  Perovskite nanocrystal light-emitting diodes (LEDs) employing architecture
comprising a ZnO nanoparticles electron-transport layer and a conjugated
polymer hole-transport layer have been fabricated. The obtained LEDs
demonstrate a maximum external-quantum-efficiency of 6.04%, luminance of 12998
Cd/m2 and stable electroluminescence at 519 nm. Importantly, such high
efficiency and brightness have been achieved by employing solution processed
transport layers, formamidinium lead bromide nanocrystals (CH(NH2)2PbBr3 NCs)
synthesized at room-temperature and in air without the use of a Schlenk line,
and a procedure based on atomic layer deposition to insolubilize the NC film.
The obtained NCs show a photoluminescence quantum yield of 90% that is retained
upon film fabrica-tion. The results show that perovskite NC LEDs can achieve
high-performance without the use of transport layers deposited through
evapo-ration in ultra-high-vacuum.
