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 CsPb_1-xSnxBr₃ increased from 45% to 83% with Sn^IV substitution. The transient absorption (TA) exciton dynamics in undoped CsPbBr₃ and CsPb_0.67Sn_0.33Br₃ 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 CsPb_0.67Sn_0.33Br₃ QDs emit at 517nm. 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 3.6V, which are the best values among reported tin-based perovskite quantum-dot LEDs.

10.1002/anie.201706860