High-Performance CsPb1-xSnxBr3 Perovskite Quantum Dots for Light-Emitting Diodes

All inorganic CsPbBr3 perovskite quantum dots (QDs) are potential emitters for electroluminescent displays. We have developed a facile hot-injection method to partially replace the toxic Pb2+ with highly stable Sn4+. Meanwhile, the absolute photoluminescence quantum yield of CsPb1-xSnxBr3 increased from 45% to 83% with Sn-IV substitution. The transient absorption (TA) exciton dynamics in undoped CsPbBr3 and CsPb0.67Sn0.33Br3 QDs at various excitation fluences were determined by femtosecond transient absorption, time-resolved photoluminescence, and single-dot spectroscopy, providing clear evidence for the suppression of trion generation by Sn doping. These highly luminescent CsPb0.67Sn0.33Br3 QDs emit at 517 nm. A device based on these QDs exhibited a luminance of 12 500 cd m(-2), a current efficiency of 11.63 cd A(-1), an external quantum efficiency of 4.13%, a power efficiency of 6.76 lm w(-1), and a low turn-on voltage of 3.6 V, which are the best values among reported tin-based perovskite quantum-dot LEDs.