Table 1.
PL and EL performance of the QDs with various combinations of shells and ligands.
| Inorganic structure | Ligands | Film PL QY (%) | EQE (%) | Device lifetimea T50 (h) |
|---|---|---|---|---|
| CdSe/CdS | Cd(RCOO)2 | 77 ± 2 | 0.25 ± 0.08 | ~0.3 |
| Cd(RPOOO) | 70 ± 3 | 0.1–0.3 | ~1 | |
| Zn(RCOO)2 | 75 ± 2 | 2–4 | ~5–7 | |
| Mg(RCOO)2 | 42 ± 3 | 8–9 | ~8000 | |
| RNH2 + RSH | 77 ± 2 | 18–20 | ~90,000 | |
| RNH2b | 76 ± 2 | 18.5 ± 0.6 | ~90,000 | |
| RNH2 | 76 ± 2 | 18.6 ± 0.6 | ~90,000 | |
| CdSe/CdS/ZnS | Zn(RCOO)2 | 80 ± 2 | 2.7 ± 0.5 | ~3–5 |
| TOPc | 79 ± 2 | 15.4 ± 0.6 | T95 @1000 nits ~400 | |
| RNH2b | 79 ± 2 | 17.8 ± 0.4 | T95 @1000 nits ~600 | |
| RNH2 + RSHb | 78 ± 2 | 17–19 | T95 @1000 nits ~550 | |
| CdSe/CdZnSe/CdZnS | Zn(RCOO)2 | 74 ± 2 | 5–7 | T95 @1000 nits ~80 |
| TOPc | 75 ± 2 | 15.8 ± 0.9 | T95 @1000 nits ~3800 |
The data shown in italics are from QDs with electrochemically reactive ligands and the rest of the data are from QDs with electrochemically inert ligands.
aThe device lifetimes are estimated at an initial brightness of 100 nits if not noted.
bThese QDs are determined to retain their negatively charged carboxylate ligands (~15% of residual carboxylate ligands).
cThe percentage of carboxylate ligands of these QDs after ligand exchange by TOP was ~25%. This value is the lower limit for maintaining the dispersity of these QDs after TOP treatment.