High-Performance CsPb1−x Sn x Br3 Perovskite Quantum Dots for Light-Emitting Diodes

All inorganic CsPbBr3 perovskite quantum dots (QDs) are potential emitters for electroluminescent display. We demonstrated an easy hot-injection method to partially replace the toxic Pb2+ with the highly stable Sn4+. Meanwhile, the absolute photoluminescence (PL) quantum yield of CsPb1-xSnxBr3 with Sn(IV) substitution increased from 45% to 83%. Based on femtosecond transient-absorption (TA), time-resolved PL, and single-dot spectroscopies, TA dynamics in undoped CsPbBr3 and CsPb0.67Sn0.33Br3 QDs at various excitation fluences., providing a clear evidence for the suppression of trion generation. These highly luminescent CsPb0.67Sn0.33Br3 QDs exhibit emission wavelength of 517 nm. The highest device performance exhibited a luminescence of 12,500 cd/m2, a current efficiency (CE) of 11.63 cd/A, an external quantum efficiency (EQE) of 4.13%, a power efficiency (PE) of 6.76 lm/w, and a low turn-on voltage of 3.6 V, which are the highest values among reported Sn-based perovskite QLEDs.