Skip to main content
NCBI home page
ACS AuthorChoice logoLink to ACS AuthorChoice
. 2023 Mar 20;35(7):2827–2834. doi: 10.1021/acs.chemmater.2c03562

Colloidal CsPbX3 Nanocrystals with Thin Metal Oxide Gel Coatings

Dominic Guggisberg †,‡, Sergii Yakunin †,‡, Christoph Neff †, Marcel Aebli †,‡, Detlef Günther †, Maksym V Kovalenko †,‡,§,*, Dmitry N Dirin †,‡,§,*
PMCID: PMC10100534  PMID: 37063595

Abstract

graphic file with name cm2c03562_0007.jpg

Lead halide perovskite (LHP) nanocrystals (NCs) have gathered much attention as light-emitting materials, particularly owing to their excellent color purity, band gap tunability, high photoluminescence quantum yield (PLQY), low cost, and scalable synthesis. To enhance the stability of LHP NCs, bulky strongly bound organic ligands are commonly employed, which counteract the extraction of charge carriers from the NCs and hinder their use as photoconductive materials and photocatalysts. Replacing these ligands with a thin coating is a complex challenge due to the highly dynamic ionic lattice, which is vulnerable to the commonly employed coating precursors and solvents. In this work, we demonstrate thin (<1 nm) metal oxide gel coatings through non-hydrolytic sol–gel reactions. The coated NCs are readily dispersible and highly stable in short-chain alcohols while remaining monodisperse and exhibiting high PLQY (70–90%). We show the successful coating of NCs in a wide range of sizes (5–14 nm) and halide compositions. Alumina-gel-coated NCs were chosen for an in-depth analysis, and the versatility of the approach is demonstrated by employing zirconia- and titania-based coatings. Compact films of the alumina-gel-coated NCs exhibit electronic and excitonic coupling between the NCs, leading to two orders of magnitude longer photoluminescence lifetimes (400–700 ns) compared to NCs in solution or their organically capped counterparts. This makes these NCs highly suited for applications where charge carrier delocalization or extraction is essential for performance.

Introduction

Lead halide perovskite (LHP) nanocrystals (NCs) have emerged as promising light-emitting materials1−3 for liquid crystal displays,4−7 LEDs,8−11 lasers,12−14 scintillators,15−17 luminescent solar concentrators.18−20 and as quantum emitters.21−24 They combine broadly tunable emission colors (405–770 nm)25,26 with high photoluminescence quantum yield (PLQY)25−27 and PL linewidths as narrow as 70 meV, enabling exceptional color purity.28 Recently, LHP NCs have also been considered as photocatalysts29−38 or photoconductive materials.39,40 These applications would greatly benefit from surface accessibility and energy transfer capabilities.33−35,41−43

While the commonly employed long-chain organic ligands provide surface passivation and render NCs colloidally stable, they also act as an insulating barrier. Smaller ligands, especially inorganic ones, have shown to greatly improve the charge transport in nanocrystal solids.44,45 Unfortunately, the choice of materials for inorganic coatings is severely limited due to the structurally labile lattice of LHPs.2 First, the coating material needs to be thermodynamically stable enough to protect the LHP core from any outside influence and prevent the diffusion of the highly mobile halide anions out of the NCs. Second, among the stable materials, those that react with the LHP or employ precursors reactive toward the LHP need to be excluded as well. This eliminates most halide and chalcogenide salts since they lead to anion exchange or extraction of the Pb to form a more stable compound (PbF2, PbS, PbSe, etc.). Third, the coating should not introduce trap states or significantly alter the optical properties. The obvious choice that remained for us was oxide-based coatings. Recently, many groups have focused on encapsulating LHP NCs in an oxide-based inorganic matrix46−49 or tried to synthesize stable LHP core/inorganic shell NCs.3,50−52 A vast majority of these publications are based on SiO2 and related oxides, showing that they are indeed chemically inert toward the LHP and that the optical properties of coated NCs remain virtually unchanged.3,51,53 However, most of these works focus on rather thick coatings in an attempt to create fully environmentally stable LHP compounds. On the contrary, in this work, we sought to realize colloidally and environmentally stable LHP NCs coated with a thin inorganic layer and free of bulky organic ligands.

Besides the coating material, the synthesis path must be judiciously chosen too. A common theme among the published oxide coatings for LHP NCs is the hydrolytic sol–gel reaction used for synthesis. Hence, the synthesis outcome is a compromise between the rate of NC degradation and shell formation. Buonsanti et al. proposed a work-around by using an aluminum precursor that reacts with molecular oxygen to give a mixed alumina-organic ligand coating.57 To our knowledge, a non-hydrolytic sol gel reaction has thus far not been reported for coating LHP NCs. Herein, we present such a path, yielding a sub-nm thin oxide gel coating. The obtained NCs proved to be more stable toward polar organic solvents than their organically capped counterparts while only being covered by a thin gel layer. We showcase alumina-, titania-, and zirconia-based coatings to demonstrate the versatility of this approach. Compact films of such NCs feature strong delocalization of the photoexcited carriers, leading to PL lifetimes two orders of magnitude longer (400–700 ns) than their organically capped counterparts, opening an avenue for applications where strong electronic coupling of individual NCs is essential.

Results and Discussion

Alumina-gel-coated LHP NCs were obtained by first synthesizing organically capped NCs (Figure 1b) using a scaled-up synthesis previously reported by our group (synthesis details in the Supporting Information).58 CsPbBr3 NCs capped with 3-(N,N-dimethyloctadecylammonio)propanesulfonate (ASC18), a zwitterionic ligand introduced in our earlier work,59 were determined to work best for the subsequent alumina gel coating. The commonly employed oleic acid/oleylamine ligand system25 did not sufficiently protect the NCs during the coating step, and the NCs sintered and degraded before a sufficient amount of coating material was deposited. A similar outcome was observed for other ligands; for example, phosphatidylcholine-based ligands like lecithin60 degraded when heated and consequently were not capable of protecting the NCs. In the second step, the sol–gel coating was formed by reacting an aluminum halide AlX3 (X = Cl, Br, and I) and an aluminum alkoxide Al(OR)3 (R = Et, sBu, tBu, and Ph) in the presence of NCs, as outlined in Figure 1a.54−56 Particularly, ASC18-capped CsPbBr3 NCs (0.12 mmol) in toluene were mixed with ODE (12 mL) and dried under vacuum. A solution of AlBr3 (0.18 mmol) and Al(OsBu)3 (0.18 mmol) in anhydrous mesitylene (1 mL) was prepared in the glovebox and injected into the NC colloid at room temperature under vigorous stirring. The solution was subsequently heated to 120 °C for 10 min and then cooled to room temperature with a water bath. Coated NCs were precipitated from the crude solution with acetone (24 mL), leading to a final hydrolysis step of the gel with present trace amounts of water. This also introduced surface charges, and the NCs were now dispersible in short-chain alcohols such as ethanol, isopropanol, or n-butanol. Particularly, in n-butanol, high concentrations (up to 100 mg/mL of LHP) could be obtained. An excess alumina gel is produced, which displaces the zwitterionic ligands on the surface. The amount of aluminum precursors is adjusted such that the formation of free gel is minimized. When formed, the excess gel can either be kept for additional protection, in particular, when producing films, or be washed away. Alumina-gel-coated NCs can be precipitated multiple times with diethyl ether or hexane and re-dispersed in the solvent of choice. This gradually reduces the amount of free gel in solution until a clean NC dispersion is obtained after 3 to 5 washing cycles. Typical transmission electron microscopy (TEM) images show fairly uniform perovskite NCs with a faint, low-contrast border attributed to the alumina gel coating (Figure 1c). Well-purified samples generally display very thin coatings (on the order of 1 nm) that are difficult to image even with a high-resolution TEM. In less purified samples, NCs with thicker coatings (up to 5 nm) can be found (Figure S1). The final NC dispersions show narrow emission (FWHM <20 nm) between 490 and 515 nm (depending on the size of NCs) with a PLQY of 70 to 90% (Figure 1d).

Figure 1.

Figure 1

Open in a new tab

(a) Reaction scheme for the formation of an alumina gel by condensation of aluminum bromide and an aluminum alkoxide via alkyl halide elimination. An alumina gel is produced after heating to 120 °C and is capable of further hydrolyzing when exposed to ambient humidity.54−56 (b,c) TEM images of zwitterion-capped and alumina-gel-coated CsPbBr3 NCs. (d) Normalized absorption and emission spectra of the initial zwitterion-capped NCs (gray lines) and the alumina-gel-coated NCs (black lines), with a representative image of alumina-gel-coated CsPbBr3 NCs dispersed in n-butanol.

Colloidal stability in alcohols evidences a surface modification upon sol–gel reaction, although the proof of an alumina gel coating is not straightforward. Inductively coupled plasma mass spectrometry (ICP–MS) elemental analysis yields the amount of Al-species that are tightly bound to the NCs and not removed during washing (Figure 2a). In this analysis, we compare a non-washed, a once-washed, and a five times-purified sample. All samples were precipitated with diethyl ether, dried under vacuum, and digested in a microwave with nitric acid. The ICP–MS measurement of the unwashed sample shows that all the aluminum put into the reaction could be recovered. Already, a single washing cycle removes approximately half of the aluminum from the sample, whereas the five times-purified sample had only 0.5 equiv of aluminum compared to lead remaining. Using this value, we determined the coating thickness to be less than 0.5 nm, corresponding to a mono-to-bilayer of aluminum-oxo species at most (calculation details in the Supporting Information). 27Al solid-state nuclear magnetic resonance (NMR) experiments were acquired to further characterize the alumina coating. A 1D spectrum of an alumina sol sample prepared without the addition of NCs shows a multitude of 4-, 5-, and 6-fold coordinated (at 65, 35, and 0 ppm, respectively) AlOx-species (Figure S2).54 Upon addition of NCs to the reaction, the undercoordinated aluminum species disappear. To increase the resolution, a multiple quantum magic-angle spinning (MQMAS) sequence61 was applied to an extensively washed NC sample (Figure 2b). This method separates the anisotropic quadrupole interaction from the isotropic chemical shift, thus allowing for a better identification of individual atomic environments, even in amorphous materials. Two distinct 6-fold coordinated species can be observed at 7 and 14 ppm, both exhibiting narrow peaks with 1 kHz FWHM and only a minor quadrupole-induced shift (QIS) of 4 ppm. These results show a high degree of symmetry around the aluminum atoms in alumina gel coating.

Figure 2.

Figure 2

Open in a new tab

(a) Elemental composition of alumina-gel-coated NCs as derived from ICP–MS elemental analysis, normalized to the amount of Pb. Samples were washed to three different degrees without loss of colloidal stability or change in optical properties. (b) Solid-state 27Al MQMAS NMR spectrum of alumina-gel-coated NCs. Two distinct 6-fold coordinated AlOx species can be observed.54 (c) Change in the ζ potential of alumina-gel-coated NCs when adding the base triethylamine. The inset is a representative ζ potential measurement of alumina-gel-coated NCs in butanol where no base was added.

The alumina-gel-coated NCs are stabilized in solution via surface charge. To probe this charge, ζ potential (ZP) measurements were conducted. A potential of +30 to +40 mV was determined with no obvious trend on the amount of washing or coating thickness. This is on par with ζ potentials of aqueous Al2O3 NCs at pH 7.62−64 The charge in oxide systems stems from protonated/deprotonated oxo-species on the surface. As such, the charge is pH-dependent. The concept of pH does not directly translate to other solvents, but it should still be possible to deprotonate the NCs with a suitably strong base. Therefore, we added a controlled amount of triethylamine to NC solutions and found that the charge could be decreased to a minimum of about −4 mV (Figure 2c). When plotting the amount of base added on a log scale, the decrease in ZP becomes linear (Figure S5), similar to the linear dependence of ZP on pH that is often reported. Unfortunately, lower ZP values could not be measured due to the NCs starting to degrade under the measurement conditions when higher amounts of base were added.

Three NC sizes were utilized to find that our coating approach is applicable for all sizes of NCs without compromising the NC’ integrity (Figure 3a). Since the coating obscures the effective core size in the TEM images, we used the maximum of the first absorption peak and the sizing curve published by Akkerman et al.58 to determine the core size. In all cases, the size increased only marginally from 4.6, 8.2, and 13.2 nm to 5.3, 8.5, and 13.6 nm, respectively.

Figure 3.

Figure 3

Open in a new tab

(a) Absorption and emission spectra of three different sizes of alumina-gel-coated NCs. (b,c) Normalized emission and the respective absorption spectra of alumina-gel-coated NCs with different compositions.

LHP NCs feature PL that can be tuned throughout the whole visible spectrum by adjusting the halide composition.25 Since the coating procedure requires an aluminum halide, we adopted an approach wherein the coating and anion exchange65 occur simultaneously. A series of PL and absorption spectra covering the visible spectral range (Figure 3b,c) was obtained by varying the precursor ratios; AlCl3/AlBr3 (using CsPbCl3 or CsPbBr3 cores) or AlBr3/AlI3 (using CsPbBr3 cores). Successful coating was possible for any Cl–Br mixed composition. In the Br–I system, we could reach 80% iodine content, although the samples with more than 50% I were unstable. The polar sol–gel coating facilitated the expulsion of iodine from the NC core and promoted the transformation into the non-luminescent δ-phase66,67 upon dispersion in polar solvents. The thin labile gel coating does not prevent anion exchange between NCs of different compositions. In contrast, the unwashed samples coated with a weakly bound but thick gel layer exhibit several times slower anion exchange than the original organically capped NCs.65

Replacing the thick (∼2 nm) organic ligand shell with a thin (<0.5 nm) alumina gel coating is expected to enhance electronic and excitonic coupling of the NCs in a compact NC solid.68,69 When two or more semiconductor NCs are in close proximity to each other, their wave functions can couple to form delocalized states. This coupling manifests itself in a slight decrease in PL energy (Figure S8a) and a drastic extension of the time-resolved PL (TRPL) decay of alumina-gel-coated LHP NCs in compact film compared to the dilute solutions of the same NCs or analogous NCs capped with organic ligands (Figure 4a).

Figure 4.

Figure 4

Open in a new tab

(a) TRPL traces for various NCs in solutions and film. (b) Humidity effect on TRPL traces for a film of alumina-gel-coated NCs. (c) Variation of TRPL lifetime with humidity. (d,e) Excitation beam intensity dependencies for TRPL traces for films of alumina-gel-coated NCs at RH = 23% (d) and RH = 75% (e). (f) Cycling of PL lifetime between the vacuum (red dots) or dry air (open black dot) and elevated humidity (filled black dots, RH = 43%—gray area) conditions.

The efficiency of electronic coupling between NCs is defined not only by the distance between them but also by the height of the tunneling barrier. We found the second factor to be decisive in the case of NCs coated with the highly hydrophilic alumina gel. The TRPL lifetime of the compact NC solid changed by almost two orders of magnitude with an increase in relative humidity (R.H.) from 23 to 75% (Figure 4b,c). We hypothesize that adsorbed water increases the hydrolysis of the nanocrystal coating or raises its conductivity and thus enhances the excitonic and electronic coupling of the nanocrystals. Stronger coupling leads to delocalization of excitons and electrons and lengthening of the PL lifetime. Excitonic coupling in humid conditions and its insignificance in dry solid are also confirmed by TRPL dependences on pumping intensity. Compact NC solids prepared at RH = 23% show little change in TRPL lifetime when the excitation beam intensity is varied by three orders of magnitude (Figure 4d). Analogous NC solids exposed to humid conditions (RH = 75%) demonstrate strong acceleration of TRPL lifetime with increasing photon flux (Figure 4e). Note that the lifetime variations are largely reversible up to RH ∼60% and are caused solely by water vapor (Figures 4f and S8b). Elevated humidity also decreases PLQY in compact films due to the more efficient carrier delocalization, which increases the chance of non-radiative recombination. Specifically, films at 23% RH reach up to 75% PLQY, while at 75% RH, roughly 40% PLQY is observed (Figure S9).

In order to demonstrate the versatility of the non-hydrolytic sol–gel approach, we also synthesized zirconia- and titania-based analogues using ZrBr4 and Zr(OBu)4 or TiBr4 and Ti(OiPr)4 precursors, respectively. Thin coatings were obtained in both cases which render the NCs stable in polar solvents. For the zirconia-coated NCs, the excess gel was difficult to wash away, and some of the leftover gel can be seen on the TEM images surrounding the NCs (Figure 5c,d). For titania, very clean and uniform coatings could be obtained (Figure 5e,f). Unfortunately, zirconia coatings seemed to be detrimental to the PLQY, and only 40–50% was achieved routinely (Figure 5a). Titania coatings severely quench the emission of LHP NCs to a level consistently lower than 0.1%, in full agreement with previous reports on TiO2 being an efficient electron scavenger for LHPs (Figure 5b).70−73 We note that the extraction of the photoexcited electrons from the conventional organically capped LHP NCs is known to be more challenging compared to the extraction of holes. Readily available and long-lived excited electrons in titania-coated LHP NCs are especially interesting for photocatalysis and open up new opportunities for LHP-based photocatalysts.

Figure 5.

Figure 5

Open in a new tab

(a,b) Absorbance and emission spectra of zirconia- and titania-coated NCs, respectively. (c,d) TEM images of zirconia-coated NCs with excess zirconia sol visible around the NCs which cannot be removed to the same degree as for the other compositions. (e,f) TEM images of titania-coated NCs showing very uniform coatings.

Conclusions

We successfully coated LHP NCs with thin alumina-, zirconia-, and titania-based gels, which render NCs colloidally stable in short-chain alcohols. These coatings could be applied to NCs of any size in the range of 5–14 nm or halide composition without deterioration of the optical properties in the case of alumina gel coatings. Thin inorganic coatings make photoexcited carriers in LHP NCs more accessible, which is evidenced by electronic and excitonic coupling between NCs in a compact solid and opens up new opportunities for applications where carrier extraction or delocalization are essential.

Experimental Methods

Full experimental procedures are provided in the Supporting Information.

Alumina Gel-Coated CsPbBr3 NCs

In a typical synthesis, 0.12 mmol of the ASC18-capped NCs was mixed with ODE (12 mL), and the toluene was evaporated under vacuum. In the glovebox, a previously prepared solution of Al(OsBu)3 (0.36 mL, 0.5 M in mesitylene, 0.18 mmol) was taken and mixed with a solution of AlBr3 (48 mg, 0.18 mmol) in 0.4 mL of anhydrous mesitylene. This results in roughly 0.8 mL of Al2Br3(OsBu)3 precursor solution, which is injected into the NC solution at room temperature under continuous stirring. Due to the reactivity of this precursor solution to ambient humidity, it was transferred to the reaction flask using a sealed syringe. The reaction was then heated to 120 °C as fast as possible using a heating mantle and kept at 120 °C for 10 min. After the reaction period, the flask was cooled back to room temperature using a water bath. The NCs were precipitated from the crude solution with acetone (12 mL). After precipitation, the turbid solution was centrifuged at 12.1k rpm (20,130 g) for 1 min, and the supernatant was discarded. The NCs were washed by dispersion in n-butanol (1 mL) and precipitation with diethyl ether (20–40 mL depending on the colloidal stability), followed by centrifugation at 12.1k rpm (20,130 g) for 1 min. The product was finally dispersed in 2–6 mL of an alcohol (ethanol, isopropanol, or n-butanol) and centrifuged once more at 12.1k rpm (20,130 g) for 2 min to remove any aggregated particles.

Acknowledgments

This work was financially supported by the Swiss Innovation Agency (Innosuisse, no. 32908.1 IP-EE) and as part of NCCR Catalysis (grant number 180544), a National Centre of Competence in Research funded by the Swiss National Science Foundation. The authors are thankful for the funding received from the European Union through the Horizon 2020 research and innovation program (grant agreement no. 819740, project SCALE-HALO). The authors are thankful for the access of the Scientific Center for Optical and Electron Microscopy (ScopeM) and their facilities. The authors thank Dr. Frank Krumeich for the acquisition of the SEM EDX data.

Supporting Information Available

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.chemmater.2c03562.

  • Materials information, synthesis procedures, characterization details, analysis of an alumina sol, SEM EDX data, PXRD pattern, ζ potential measurements, ICP–MS data of alumina-gel-coated NCs, coating thickness and sizing curve calculations, TEM images of different sizes and different compositions, as well as additional TRPL measurements (PDF)

Author Contributions

The manuscript was written through contributions of all authors listed. All authors have given approval to the final version of the manuscript.

The authors declare no competing financial interest.

Notes

The datasets supporting this article are made available through Zenodo at https://doi.org./10.5281/zenodo.7645376.

Supplementary Material

cm2c03562_si_001.pdf (2.7MB, pdf)

References

  1. Kovalenko M. V.; Protesescu L.; Bodnarchuk M. I. Properties and potential optoelectronic applications of lead halide perovskite nanocrystals. Science 2017, 358, 745–750. 10.1126/science.aam7093. [DOI] [PubMed] [Google Scholar]
  2. Akkerman Q. A.; Rainò G.; Kovalenko M. V.; Manna L. Genesis, challenges and opportunities for colloidal lead halide perovskite nanocrystals. Nat. Mater. 2018, 17, 394–405. 10.1038/s41563-018-0018-4. [DOI] [PubMed] [Google Scholar]
  3. Dey A.; Ye J.; De A.; Debroye E.; Ha S. K.; Bladt E.; Kshirsagar A. S.; Wang Z.; Yin J.; Wang Y.; Quan L. N.; Yan F.; Gao M.; Li X.; Shamsi J.; Debnath T.; Cao M.; Scheel M. A.; Kumar S.; Steele J. A.; Gerhard M.; Chouhan L.; Xu K.; Wu X. G.; Li Y.; Zhang Y.; Dutta A.; Han C.; Vincon I.; Rogach A. L.; Nag A.; Samanta A.; Korgel B. A.; Shih C. J.; Gamelin D. R.; Son D. H.; Zeng H.; Zhong H.; Sun H.; Demir H. V.; Scheblykin I. G.; Mora-Seró I.; Stolarczyk J. K.; Zhang J. Z.; Feldmann J.; Hofkens J.; Luther J. M.; Pérez-Prieto J.; Li L.; Manna L.; Bodnarchuk M. I.; Kovalenko M. V.; Roeffaers M. B. J.; Pradhan N.; Mohammed O. F.; Bakr O. M.; Yang P.; Müller-Buschbaum P.; Kamat P. V.; Bao Q.; Zhang Q.; Krahne R.; Galian R. E.; Stranks S. D.; Bals S.; Biju V.; Tisdale W. A.; Yan Y.; Hoye R. L. Z.; Polavarapu L. State of the Art and Prospects for Halide Perovskite Nanocrystals. ACS Nano 2021, 15, 10775–10981. 10.1021/acsnano.0c08903. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Zhou Q.; Bai Z.; Lu W.-g.; Wang Y.; Zou B.; Zhong H. In Situ Fabrication of Halide Perovskite Nanocrystal-Embedded Polymer Composite Films with Enhanced Photoluminescence for Display Backlights. Adv. Mater. 2016, 28, 9163–9168. 10.1002/adma.201602651. [DOI] [PubMed] [Google Scholar]
  5. Yoon H. C.; Lee H.; Kang H.; Oh J. H.; Do Y. R. Highly efficient wide-color-gamut QD-emissive LCDs using red and green perovskite core/shell QDs. J. Mater. Chem. C 2018, 6, 13023–13033. 10.1039/c8tc04537b. [DOI] [Google Scholar]
  6. Lu M.; Zhang Y.; Wang S.; Guo J.; Yu W. W.; Rogach A. L. Metal Halide Perovskite Light-Emitting Devices: Promising Technology for Next-Generation Displays. Adv. Funct. Mater. 2019, 29, 1902008. 10.1002/adfm.201902008. [DOI] [Google Scholar]
  7. Lee H.; Park J.; Kim S.; Lee S.-C.; Kim Y.-H.; Lee T.-W. Perovskite Emitters as a Platform Material for Down-Conversion Applications. Adv. Mater. Technol. 2020, 5, 2000091. 10.1002/admt.202000091. [DOI] [Google Scholar]
  8. Dong Y.; Wang Y.-K.; Yuan F.; Johnston A.; Liu Y.; Ma D.; Choi M.-J.; Chen B.; Chekini M.; Baek S.-W.; Sagar L. K.; Fan J.; Hou Y.; Wu M.; Lee S.; Sun B.; Hoogland S.; Quintero-Bermudez R.; Ebe H.; Todorovic P.; Dinic F.; Li P.; Kung H. T.; Saidaminov M. I.; Kumacheva E.; Spiecker E.; Liao L.-S.; Voznyy O.; Lu Z.-H.; Sargent E. H. Bipolar-shell resurfacing for blue LEDs based on strongly confined perovskite quantum dots. Nat. Nanotechnol. 2020, 15, 668–674. 10.1038/s41565-020-0714-5. [DOI] [PubMed] [Google Scholar]
  9. Kim Y.-H.; Kim S.; Kakekhani A.; Park J.; Park J.; Lee Y.-H.; Xu H.; Nagane S.; Wexler R. B.; Kim D.-H.; Jo S. H.; Martínez-Sarti L.; Tan P.; Sadhanala A.; Park G.-S.; Kim Y.-W.; Hu B.; Bolink H. J.; Yoo S.; Friend R. H.; Rappe A. M.; Lee T.-W. Comprehensive defect suppression in perovskite nanocrystals for high-efficiency light-emitting diodes. Nat. Photonics 2021, 15, 148–155. 10.1038/s41566-020-00732-4. [DOI] [Google Scholar]
  10. Hassan Y.; Park J. H.; Crawford M. L.; Sadhanala A.; Lee J.; Sadighian J. C.; Mosconi E.; Shivanna R.; Radicchi E.; Jeong M.; Yang C.; Choi H.; Park S. H.; Song M. H.; De Angelis F.; Wong C. Y.; Friend R. H.; Lee B. R.; Snaith H. J. Ligand-engineered band gap stability in mixed-halide perovskite LEDs. Nature 2021, 591, 72–77. 10.1038/s41586-021-03217-8. [DOI] [PubMed] [Google Scholar]
  11. Wang Y.-K.; Yuan F.; Dong Y.; Li J.-Y.; Johnston A.; Chen B.; Saidaminov M. I.; Zhou C.; Zheng X.; Hou Y.; Bertens K.; Ebe H.; Ma D.; Deng Z.; Yuan S.; Chen R.; Sagar L. K.; Liu J.; Fan J.; Li P.; Li X.; Gao Y.; Fung M.-K.; Lu Z.-H.; Bakr O. M.; Liao L.-S.; Sargent E. H. All-Inorganic Quantum-Dot LEDs Based on a Phase-Stabilized α-CsPbI3 Perovskite. Angew. Chem., Int. Ed. 2021, 60, 16164–16170. 10.1002/anie.202104812. [DOI] [PubMed] [Google Scholar]
  12. Li S.; Lei D.; Ren W.; Guo X.; Wu S.; Zhu Y.; Rogach A. L.; Chhowalla M.; Jen A. K. Y. Water-resistant perovskite nanodots enable robust two-photon lasing in aqueous environment. Nat. Commun. 2020, 11, 1192. 10.1038/s41467-020-15016-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Chen J.; Du W.; Shi J.; Li M.; Wang Y.; Zhang Q.; Liu X. Perovskite quantum dot lasers. InfoMat 2020, 2, 170–183. 10.1002/inf2.12051. [DOI] [Google Scholar]
  14. Zhang Q.; Shang Q.; Su R.; Do T. T. H.; Xiong Q. Halide Perovskite Semiconductor Lasers: Materials, Cavity Design, and Low Threshold. Nano Lett. 2021, 21, 1903–1914. 10.1021/acs.nanolett.0c03593. [DOI] [PubMed] [Google Scholar]
  15. Chen Q.; Wu J.; Ou X.; Huang B.; Almutlaq J.; Zhumekenov A. A.; Guan X.; Han S.; Liang L.; Yi Z.; Li J.; Xie X.; Wang Y.; Li Y.; Fan D.; Teh D. B. L.; All A. H.; Mohammed O. F.; Bakr O. M.; Wu T.; Bettinelli M.; Yang H.; Huang W.; Liu X. All-inorganic perovskite nanocrystal scintillators. Nature 2018, 561, 88–93. 10.1038/s41586-018-0451-1. [DOI] [PubMed] [Google Scholar]
  16. Gandini M.; Villa I.; Beretta M.; Gotti C.; Imran M.; Carulli F.; Fantuzzi E.; Sassi M.; Zaffalon M.; Brofferio C.; Manna L.; Beverina L.; Vedda A.; Fasoli M.; Gironi L.; Brovelli S. Efficient, fast and reabsorption-free perovskite nanocrystal-based sensitized plastic scintillators. Nat. Nanotechnol. 2020, 15, 462–468. 10.1038/s41565-020-0683-8. [DOI] [PubMed] [Google Scholar]
  17. Montanarella F.; McCall K. M.; Sakhatskyi K.; Yakunin S.; Trtik P.; Bernasconi C.; Cherniukh I.; Mannes D.; Bodnarchuk M. I.; Strobl M.; Walfort B.; Kovalenko M. V. Highly Concentrated, Zwitterionic Ligand-Capped Mn2+:CsPb(BrxCl1–x)3 Nanocrystals as Bright Scintillators for Fast Neutron Imaging. ACS Energy Lett. 2021, 6, 4365–4373. 10.1021/acsenergylett.1c01923. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Meinardi F.; Akkerman Q. A.; Bruni F.; Park S.; Mauri M.; Dang Z.; Manna L.; Brovelli S. Doped Halide Perovskite Nanocrystals for Reabsorption-Free Luminescent Solar Concentrators. ACS Energy Lett. 2017, 2, 2368–2377. 10.1021/acsenergylett.7b00701. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Wei M.; de Arquer F. P. G.; Walters G.; Yang Z.; Quan L. N.; Kim Y.; Sabatini R.; Quintero-Bermudez R.; Gao L.; Fan J. Z.; Fan F.; Gold-Parker A.; Toney M. F.; Sargent E. H. Ultrafast narrowband exciton routing within layered perovskite nanoplatelets enables low-loss luminescent solar concentrators. Nat. Energy 2019, 4, 197–205. 10.1038/s41560-018-0313-y. [DOI] [Google Scholar]
  20. Wu J.; Tong J.; Gao Y.; Wang A.; Zhang T.; Tan H.; Nie S.; Deng Z. Efficient and Stable Thin-Film Luminescent Solar Concentrators Enabled by Near-Infrared Emission Perovskite Nanocrystals. Angew. Chem., Int. Ed. 2020, 59, 7738–7742. 10.1002/anie.201911638. [DOI] [PubMed] [Google Scholar]
  21. Park Y.-S.; Guo S.; Makarov N. S.; Klimov V. I. Room Temperature Single-Photon Emission from Individual Perovskite Quantum Dots. ACS Nano 2015, 9, 10386–10393. 10.1021/acsnano.5b04584. [DOI] [PubMed] [Google Scholar]
  22. Utzat H.; Sun W.; Kaplan A. E. K.; Krieg F.; Ginterseder M.; Spokoyny B.; Klein N. D.; Shulenberger K. E.; Perkinson C. F.; Kovalenko M. V.; Bawendi M. G. Coherent single-photon emission from colloidal lead halide perovskite quantum dots. Science 2019, 363, 1068–1072. 10.1126/science.aau7392. [DOI] [PubMed] [Google Scholar]
  23. Hsu B.-W.; Chuang Y.-T.; Cheng C.-Y.; Chen C.-Y.; Chen Y.-J.; Brumberg A.; Yang L.; Huang Y.-S.; Schaller R. D.; Chen L.-J.; Chuu C.-S.; Lin H.-W. Very Robust Spray-Synthesized CsPbI3 Quantum Emitters with Ultrahigh Room-Temperature Cavity-Free Brightness and Self-Healing Ability. ACS Nano 2021, 15, 11358–11368. 10.1021/acsnano.1c00733. [DOI] [PubMed] [Google Scholar]
  24. Zhu C.; Marczak M.; Feld L.; Boehme S. C.; Bernasconi C.; Moskalenko A.; Cherniukh I.; Dirin D.; Bodnarchuk M. I.; Kovalenko M. V.; Rainò G. Room-Temperature, Highly Pure Single-Photon Sources from All-Inorganic Lead Halide Perovskite Quantum Dots. Nano Lett. 2022, 22, 3751–3760. 10.1021/acs.nanolett.2c00756. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Protesescu L.; Yakunin S.; Bodnarchuk M. I.; Krieg F.; Caputo R.; Hendon C. H.; Yang R. X.; Walsh A.; Kovalenko M. V. Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, and I): Novel Optoelectronic Materials Showing Bright Emission with Wide Color Gamut. Nano Lett. 2015, 15, 3692–3696. 10.1021/nl5048779. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Protesescu L.; Yakunin S.; Kumar S.; Bär J.; Bertolotti F.; Masciocchi N.; Guagliardi A.; Grotevent M.; Shorubalko I.; Bodnarchuk M. I.; Shih C.-J.; Kovalenko M. V. Dismantling the “Red Wall” of Colloidal Perovskites: Highly Luminescent Formamidinium and Formamidinium–Cesium Lead Iodide Nanocrystals. ACS Nano 2017, 11, 3119–3134. 10.1021/acsnano.7b00116. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Dutta A.; Behera R. K.; Pal P.; Baitalik S.; Pradhan N. Near-Unity Photoluminescence Quantum Efficiency for All CsPbX3 (X=Cl, Br, and I) Perovskite Nanocrystals: A Generic Synthesis Approach. Angew. Chem., Int. Ed. 2019, 58, 5552–5556. 10.1002/anie.201900374. [DOI] [PubMed] [Google Scholar]
  28. Rainò G.; Yazdani N.; Boehme S. C.; Kober-Czerny M.; Zhu C.; Krieg F.; Rossell M. D.; Erni R.; Wood V.; Infante I.; Kovalenko M. V. Ultra-narrow room-temperature emission from single CsPbBr3 perovskite quantum dots. Nat. Commun. 2022, 13, 2587. 10.1038/s41467-022-30016-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Zhu X. L.; Lin Y. X.; Sun Y.; Beard M. C.; Yan Y. Lead-Halide Perovskites for Photocatalytic alpha-Alkylation of Aldehydes. J. Am. Chem. Soc. 2019, 141, 733–738. 10.1021/jacs.8b08720. [DOI] [PubMed] [Google Scholar]
  30. Huang H. W.; Yuan H. F.; Zhao J. W.; Solís-Fernández G.; Zhou C.; Seo J. W.; Hendrix J.; Debroye E.; Steele J. A.; Hofkens J.; Long J. L.; Roeffaers M. B. J. C(sp3)-H Bond Activation by Perovskite Solar Photocatalyst Cell. ACS Energy Lett 2019, 4, 203–208. 10.1021/acsenergylett.8b01698. [DOI] [Google Scholar]
  31. Zhu X.; Lin Y.; San Martin J.; Sun Y.; Zhu D.; Yan Y. Lead halide perovskites for photocatalytic organic synthesis. Nat. Commun. 2019, 10, 2843. 10.1038/s41467-019-10634-x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Luo X.; Lai R.; Li Y.; Han Y.; Liang G.; Liu X.; Ding T.; Wang J.; Wu K. Triplet Energy Transfer from CsPbBr3 Nanocrystals Enabled by Quantum Confinement. J. Am. Chem. Soc. 2019, 141, 4186–4190. 10.1021/jacs.8b13180. [DOI] [PubMed] [Google Scholar]
  33. Lu H.; Zhu X.; Miller C.; San Martin J.; Chen X.; Miller E. M.; Yan Y.; Beard M. C. Enhanced photoredox activity of CsPbBr3 nanocrystals by quantitative colloidal ligand exchange. J. Chem. Phys. 2019, 151, 204305. 10.1063/1.5129261. [DOI] [PubMed] [Google Scholar]
  34. Jiang Y.; Weiss E. A. Colloidal Quantum Dots as Photocatalysts for Triplet Excited State Reactions of Organic Molecules. J. Am. Chem. Soc. 2020, 142, 15219–15229. 10.1021/jacs.0c07421. [DOI] [PubMed] [Google Scholar]
  35. Kobosko S. M.; DuBose J. T.; Kamat P. V. Perovskite Photocatalysis. Methyl Viologen Induces Unusually Long-Lived Charge Carrier Separation in CsPbBr3 Nanocrystals. ACS Energy Lett. 2020, 5, 221–223. 10.1021/acsenergylett.9b02573. [DOI] [Google Scholar]
  36. Huang H. W.; Pradhan B.; Hofkens J.; Roeffaers M. B. J.; Steele J. A. Solar-Driven Metal Halide Perovskite Photocatalysis: Design, Stability, and Performance. ACS Energy Lett 2020, 5, 1107–1123. 10.1021/acsenergylett.0c00058. [DOI] [Google Scholar]
  37. Gualdrón-Reyes A. F.; Rodríguez-Pereira J.; Amado-González E.; Rueda-P J.; Ospina R.; Masi S.; Yoon S. J.; Tirado J.; Jaramillo F.; Agouram S.; Muñoz-Sanjosé V.; Giménez S.; Mora-Seró I. Unravelling the Photocatalytic Behavior of All-Inorganic Mixed Halide Perovskites: The Role of Surface Chemical States. ACS Appl. Mater. Interfaces 2020, 12, 914–924. [DOI] [PubMed] [Google Scholar]
  38. Hu H.; Guan W.; Xu Y.; Wang X.; Wu L.; Chen M.; Zhong Q.; Xu Y.; Li Y.; Sham T.-K.; Zhang X.; Wang L.; Cao M.; Zhang Q. Construction of Single-Atom Platinum Catalysts Enabled by CsPbBr3 Nanocrystals. ACS Nano 2021, 15, 13129–13139. 10.1021/acsnano.1c02515. [DOI] [PubMed] [Google Scholar]
  39. Yakunin S.; Sytnyk M.; Kriegner D.; Shrestha S.; Richter M.; Matt G. J.; Azimi H.; Brabec C. J.; Stangl J.; Kovalenko M. V.; Heiss W. Detection of X-ray photons by solution-processed lead halide perovskites. Nat. Photonics 2015, 9, 444–449. 10.1038/nphoton.2015.82. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Nazarenko O.; Kotyrba M. R.; Wörle M.; Cuervo-Reyes E.; Yakunin S.; Kovalenko M. V. Luminescent and Photoconductive Layered Lead Halide Perovskite Compounds Comprising Mixtures of Cesium and Guanidinium Cations. Inorg. Chem. 2017, 56, 11552–11564. 10.1021/acs.inorgchem.7b01204. [DOI] [PubMed] [Google Scholar]
  41. Amin V. A.; Aruda K. O.; Lau B.; Rasmussen A. M.; Edme K.; Weiss E. A. Dependence of the Band Gap of CdSe Quantum Dots on the Surface Coverage and Binding Mode of an Exciton-Delocalizing Ligand, Methylthiophenolate. J. Phys. Chem. C 2015, 119, 19423–19429. 10.1021/acs.jpcc.5b04306. [DOI] [Google Scholar]
  42. Saran R.; Curry R. J. Lead sulphide nanocrystal photodetector technologies. Nat. Photonics 2016, 10, 81–92. 10.1038/nphoton.2015.280. [DOI] [Google Scholar]
  43. Weiss E. A. Designing the Surfaces of Semiconductor Quantum Dots for Colloidal Photocatalysis. ACS Energy Lett. 2017, 2, 1005–1013. 10.1021/acsenergylett.7b00061. [DOI] [Google Scholar]
  44. Talapin D. V.; Lee J.-S.; Kovalenko M. V.; Shevchenko E. V. Prospects of Colloidal Nanocrystals for Electronic and Optoelectronic Applications. Chem. Rev. 2010, 110, 389–458. 10.1021/cr900137k. [DOI] [PubMed] [Google Scholar]
  45. Kagan R.; Lifshitz E.; wardargent H.; Talapin V. Building devices from colloidal quantum dots. Science 2016, 353, aac5523. 10.1126/science.aac5523. [DOI] [PubMed] [Google Scholar]
  46. Dirin D. N.; Protesescu L.; Trummer D.; Kochetygov I. V.; Yakunin S.; Krumeich F.; Stadie N. P.; Kovalenko M. V. Harnessing Defect-Tolerance at the Nanoscale: Highly Luminescent Lead Halide Perovskite Nanocrystals in Mesoporous Silica Matrixes. Nano Lett. 2016, 16, 5866–5874. 10.1021/acs.nanolett.6b02688. [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Malgras V.; Tominaka S.; Ryan J. W.; Henzie J.; Takei T.; Ohara K.; Yamauchi Y. Observation of Quantum Confinement in Monodisperse Methylammonium Lead Halide Perovskite Nanocrystals Embedded in Mesoporous Silica. J. Am. Chem. Soc. 2016, 138, 13874–13881. 10.1021/jacs.6b05608. [DOI] [PubMed] [Google Scholar]
  48. Zhang Q.; Wang B.; Zheng W.; Kong L.; Wan Q.; Zhang C.; Li Z.; Cao X.; Liu M.; Li L. Ceramic-like stable CsPbBr3 nanocrystals encapsulated in silica derived from molecular sieve templates. Nat. Commun. 2020, 11, 31. 10.1038/s41467-019-13881-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
  49. An M. N.; Park S.; Brescia R.; Lutfullin M.; Sinatra L.; Bakr O. M.; De Trizio L.; Manna L. Low-Temperature Molten Salts Synthesis: CsPbBr3 Nanocrystals with High Photoluminescence Emission Buried in Mesoporous SiO2. ACS Energy Lett. 2021, 6, 900–907. 10.1021/acsenergylett.1c00052. [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Zhong Q.; Cao M.; Zhang Q. Encapsulation of lead halide perovskite nanocrystals (NCs) at the single-particle level: strategies and properties. Nanoscale 2021, 13, 19341–19351. 10.1039/d1nr05478c. [DOI] [PubMed] [Google Scholar]
  51. Duan Y.; Wang D.-Y.; Costa R. D. Recent Progress on Synthesis, Characterization, and Applications of Metal Halide Perovskites@Metal Oxide. Adv. Funct. Mater. 2021, 31, 2104634. 10.1002/adfm.202104634. [DOI] [Google Scholar]
  52. Ahmed G. H.; Yin J.; Bakr O. M.; Mohammed O. F. Successes and Challenges of Core/Shell Lead Halide Perovskite Nanocrystals. ACS Energy Lett. 2021, 6, 1340–1357. 10.1021/acsenergylett.1c00076. [DOI] [Google Scholar]
  53. Rossi C.; Scarfiello R.; Brescia R.; Goldoni L.; Caputo G.; Carbone L.; Colombara D.; De Trizio L.; Manna L.; Baranov D. Exploiting the Transformative Features of Metal Halides for the Synthesis of CsPbBr3@SiO2 Core–Shell Nanocrystals. Chem. Mater. 2022, 34, 405–413. 10.1021/acs.chemmater.1c03749. [DOI] [Google Scholar]
  54. Acosta S.; Corriu R. J. P.; Leclercq D.; Lefèvre P.; Mutin P. H.; Vioux A. Preparation of alumina gels by a non-hydrolytic sol-gel processing method. J. Non-Cryst. Solids 1994, 170, 234–242. 10.1016/0022-3093(94)90052-3. [DOI] [Google Scholar]
  55. Vioux A. Nonhydrolytic Sol–Gel Routes to Oxides. Chem. Mater. 1997, 9, 2292–2299. 10.1021/cm970322a. [DOI] [Google Scholar]
  56. Niederberger M.; Garnweitner G. Organic Reaction Pathways in the Nonaqueous Synthesis of Metal Oxide Nanoparticles. Chem. - Eur. J. 2006, 12, 7282–7302. 10.1002/chem.200600313. [DOI] [PubMed] [Google Scholar]
  57. Loiudice A.; Strach M.; Saris S.; Chernyshov D.; Buonsanti R. Universal Oxide Shell Growth Enables in Situ Structural Studies of Perovskite Nanocrystals during the Anion Exchange Reaction. J. Am. Chem. Soc. 2019, 141, 8254–8263. 10.1021/jacs.9b02061. [DOI] [PubMed] [Google Scholar]
  58. Akkerman Q. A.; Nguyen T. P. T.; Boehme S. C.; Montanarella F.; Dirin D. N.; Wechsler P.; Beiglböck F.; Rainò G.; Erni R.; Katan C.; Even J.; Kovalenko M. V. Controlling the nucleation and growth kinetics of lead halide perovskite quantum dots. Science 2022, 377, 1406–1412. 10.1126/science.abq3616. [DOI] [PubMed] [Google Scholar]
  59. Krieg F.; Ochsenbein S. T.; Yakunin S.; ten Brinck S.; Aellen P.; Süess A.; Clerc B.; Guggisberg D.; Nazarenko O.; Shynkarenko Y.; Kumar S.; Shih C.-J.; Infante I.; Kovalenko M. V. Colloidal CsPbX3 (X = Cl, Br, I) Nanocrystals 2.0: Zwitterionic Capping Ligands for Improved Durability and Stability. ACS Energy Lett. 2018, 3, 641–646. 10.1021/acsenergylett.8b00035. [DOI] [PMC free article] [PubMed] [Google Scholar]
  60. Krieg F.; Ong Q. K.; Burian M.; Rainò G.; Naumenko D.; Amenitsch H.; Süess A.; Grotevent M. J.; Krumeich F.; Bodnarchuk M. I.; Shorubalko I.; Stellacci F.; Kovalenko M. V. Stable Ultraconcentrated and Ultradilute Colloids of CsPbX3 (X = Cl, Br) Nanocrystals Using Natural Lecithin as a Capping Ligand. J. Am. Chem. Soc. 2019, 141, 19839–19849. 10.1021/jacs.9b09969. [DOI] [PMC free article] [PubMed] [Google Scholar]
  61. Frydman L.; Harwood J. S. Isotropic Spectra of Half-Integer Quadrupolar Spins from Bidimensional Magic-Angle Spinning NMR. J. Am. Chem. Soc. 1995, 117, 5367–5368. 10.1021/ja00124a023. [DOI] [Google Scholar]
  62. Sprycha R. Electrical double layer at alumina/electrolyte interface: I. Surface charge and zeta potential. J. Colloid Interface Sci. 1989, 127, 1–11. 10.1016/0021-9797(89)90002-7. [DOI] [Google Scholar]
  63. Singh B. P.; Menchavez R.; Takai C.; Fuji M.; Takahashi M. Stability of dispersions of colloidal alumina particles in aqueous suspensions. J. Colloid Interface Sci. 2005, 291, 181–186. 10.1016/j.jcis.2005.04.091. [DOI] [PubMed] [Google Scholar]
  64. López Valdivieso A.; Reyes Bahena J. L.; Song S.; Herrera Urbina R. Temperature effect on the zeta potential and fluoride adsorption at the α-Al2O3/aqueous solution interface. J. Colloid Interface Sci. 2006, 298, 1–5. 10.1016/j.jcis.2005.11.060. [DOI] [PubMed] [Google Scholar]
  65. Nedelcu G.; Protesescu L.; Yakunin S.; Bodnarchuk M. I.; Grotevent M. J.; Kovalenko M. V. Fast Anion-Exchange in Highly Luminescent Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, I). Nano Lett. 2015, 15, 5635–5640. 10.1021/acs.nanolett.5b02404. [DOI] [PMC free article] [PubMed] [Google Scholar]
  66. Trots D. M.; Myagkota S. V. High-temperature structural evolution of caesium and rubidium triiodoplumbates. J. Phys. Chem. Solids 2008, 69, 2520–2526. 10.1016/j.jpcs.2008.05.007. [DOI] [Google Scholar]
  67. Stoumpos C. C.; Kanatzidis M. G. The Renaissance of Halide Perovskites and Their Evolution as Emerging Semiconductors. Acc. Chem. Res. 2015, 48, 2791–2802. 10.1021/acs.accounts.5b00229. [DOI] [PubMed] [Google Scholar]
  68. Kovalenko M. V.; Scheele M.; Talapin D. V. Colloidal Nanocrystals with Molecular Metal Chalcogenide Surface Ligands. Science 2009, 324, 1417–1420. 10.1126/science.1170524. [DOI] [PubMed] [Google Scholar]
  69. Akselrod G. M.; Prins F.; Poulikakos L. V.; Lee E. M. Y.; Weidman M. C.; Mork A. J.; Willard A. P.; Bulović V.; Tisdale W. A. Subdiffusive Exciton Transport in Quantum Dot Solids. Nano Lett. 2014, 14, 3556–3562. 10.1021/nl501190s. [DOI] [PubMed] [Google Scholar]
  70. Kojima A.; Teshima K.; Shirai Y.; Miyasaka T. Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells. J. Am. Chem. Soc. 2009, 131, 6050–6051. 10.1021/ja809598r. [DOI] [PubMed] [Google Scholar]
  71. Lee M.; Teuscher J.; Miyasaka T.; Murakami N.; Snaith J. Efficient Hybrid Solar Cells Based on Meso-Superstructured Organometal Halide Perovskites. Science 2012, 338, 643–647. 10.1126/science.1228604. [DOI] [PubMed] [Google Scholar]
  72. Marchioro A.; Teuscher J.; Friedrich D.; Kunst M.; van de Krol R.; Moehl T.; Grätzel M.; Moser J.-E. Unravelling the mechanism of photoinduced charge transfer processes in lead iodide perovskite solar cells. Nat. Photonics 2014, 8, 250–255. 10.1038/nphoton.2013.374. [DOI] [Google Scholar]
  73. Eperon G. E.; Paternò G. M.; Sutton R. J.; Zampetti A.; Haghighirad A. A.; Cacialli F.; Snaith H. J. Inorganic caesium lead iodide perovskite solar cells. J. Mater. Chem. A 2015, 3, 19688–19695. 10.1039/c5ta06398a. [DOI] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

cm2c03562_si_001.pdf (2.7MB, pdf)

Articles from Chemistry of Materials are provided here courtesy of American Chemical Society

RESOURCES