Cheap Perovskite LEDs Achieve Efficiency Breakthrough, Threatening Traditional Display Market
Researchers have developed solution-processed perovskite light-emitting diodes that match or exceed the efficiency of conventional LED technology while using simpler, lower-cost manufacturing. The advance could disrupt a multi-billion-dollar display and lighting industry by enabling flexible screens and ultra-efficient lights produced at a fraction of current costs.
Originaltitel: Perovskite light-emitting diodes based on solution-processed self-organized multiple quantum wells
Perovskitbaserade lysdioder når nu effektivitet som gör kommersiell konkurrens möjlig. Forskare vid NanjingTech, Zhejiang University och Linköpings universitet presenterar en lösningsbearbetad perovskitLED med självorganiserade kvantbrunnar som uppnår extern kvanteffektivitet på 11,7 procent och energiomvandlingseffektivitet på 5,5 procent vid 100 mA/cm². Konstruktionen använder bandgapskonfinering — högre energiegap omsluter lågare områden som genererar ljus — för att minska ej-strålande rekombination från defekter och strömlekage. Det kritiska genomslaget är att gränssnitten mellan bandgapen inte orsakar luminescensslöckning som tidigare förutsagts. För leverantörer och produktchefer betyder detta att perovskiter kan bli konkurrenskraftiga mot OLED och konventionella halvledarlysdioder inom displaytillämpningar. Stabilitet och högeffektivitet öppnar vägen för praktiska applikationer inom några år.
<p>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.</p>