A transient-electroluminescence study on perovskite light-emitting diodes

We carried out transient-electroluminescence (Tr-EL) studies on multiple-quantum-well (MQW)-based perovskite light-emitting diodes (PeLEDs). The Tr-EL shows a short onset time (τd ∼ 0.1 μs) and rising time (τr ∼ 0.15 μs), demonstrating high carrier mobility in the MQW perovskites. The electron-mobility in the MQW perovskites was evaluated to be on the order of 10−5 cm2 V−1 s−1. When the pulses are turned off, the Tr-EL decays to zero in around 1 μs, indicating a low trap density in the MQW perovskites which was estimated to be on the order of 1015 cm−3. Besides, the Tr-EL enables us to study the EL properties of PeLEDs at intense current densities, with the results showing that both the “Auger” recombination and “Joule” heating are the main causes of the efficiency droop at current densities of tens of ampere per centimeter square.