High-Performance CsPb Sn Br Perovskite Quantum Dots for Light-Emitting Diodes.

All inorganic CsPbBr perovskite quantum dots (QDs) are potential emitters for electroluminescent displays. We have developed a facile hot-injection method to partially replace the toxic Pb with highly stable Sn . Meanwhile, the absolute photoluminescence quantum yield of CsPb Sn Br increased from 45 % to 83 % with Sn substitution. The transient absorption (TA) exciton dynamics in undoped CsPbBr and CsPb Sn Br 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 CsPb Sn Br QDs emit at 517 nm. A device based on these QDs exhibited a luminance of 12 500 cd m , a current efficiency of 11.63 cd A , an external quantum efficiency of 4.13 %, a power efficiency of 6.76 lm w , and a low turn-on voltage of 3.6 V, which are the best values among reported tin-based perovskite quantum-dot LEDs.