Figure 1.

(a–e) TEM images of CsPbBr₃ NCs synthesized by varying the alkyl chain length of secondary amines. (a) dihexylamine (DHAm), (b) dioctylamine (DOAm), (c) didecylamine (DDAm), (d) didodecylamine (DDDAm), and (e) dioctadecylamine (DODAm). (f) Corresponding XRD patterns with reference (CsPbBr₃, reference code. 96-451-0746). The presence of only the strong order peaks in the 12 nm sample (prepared with DOAm) is most likely the effect of preferential orientation for this sample. (g) Absorbance and PL spectra. The average sizes of the nanocubes measured from TEM images are written in panel f. The reaction conditions used in all these syntheses were as follows: the amount of each precursor used was 0.2 mmol of PbAc₂·3H₂O, 0.05 mmol of Cs₂CO₃, 4.75 mmol of OA, and 1.25 mmol of dialkylamine; the reaction temperature was 80 °C; 50 μL of benzoyl bromide was diluted in 0.5 mL of octadecene; the reaction time was 15 s.