Suchergebnisse

Organometal halide perovskites can be processed from solutions at low temperatures to form crystalline direct-bandgap semiconductors with promising optoelectronic properties(1-5). However, the efficiency of their electroluminescence is limited by non-radiative recombination, which is associated with defects and leakage current due to incomplete surface coverage(6-9). Here we demonstrate a solution-processed perovskite light-emitting diode (LED) based on self-organized multiple quantum wells (MQWs) with excellent film morphologies. The MQW-based LED exhibits a very high external quantum efficiency of up to 11.7%, good stability and exceptional highpower performance with an energy conversion efficiency of 5.5% at a current density of 100 mA cm(-2). This outstanding performance arises because the lower bandgap regions that generate electroluminescence are effectively confined by perovskite MQWs with higher energy gaps, resulting in very efficient radiative decay. Surprisingly, there is no evidence that the large interfacial areas between different bandgap regions cause luminescence quenching. ; Funding Agencies|National Basic Research Program of China-Fundamental Studies of Perovskite Solar Cells [2015CB932200]; Natural Science Foundation of Jiangsu Province, China [BK20131413, BK20140952, BM2012010]; National Natural Science Foundation of China [11474164, 51522209, 91433204, 61405091, 11474249]; National 973 Program of China [2015CB654901]; Jiangsu Specially-Appointed Professor programme; Synergetic Innovation Center for Organic Electronics and Information Displays; Fundamental Research Funds for the Central Universities [2015FZA3005]; China Postdoctoral Science Foundation; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; Swedish Research Council (VR) [330-2014-6433]; European Commission Marie Sklodowska-Curie actions [691210, INCA 600398]