Novel hybrid light-emitting devices based on MAPbBr₃ nanoplatelets:PVK nanocomposites and zinc oxide nanorod arrays

In this research, we demonstrate inverted perovskite light-emitting devices (PeLEDs) based on zinc oxide nanorod arrays (ZnO NAs) as the electron transport layer and methylammonium lead bromide nanoplatelets (MAPbBr₃ NPLs) as the emissive material for the first time. The polyethyleneimine ethoxylated (PEIE) was inserted between the ZnO NAs and the MAPbBr₃ NPLs layer to reduce the energy barrier and improve the electron injection efficiency. Besides, different weight ratios of poly(N-vinylcarbazole) (PVK) were blended with MAPbBr₃ NPLs to make evenly dispersed nanocomposite films, thereby enhancing the performance of devices. Meanwhile, the photoluminescence of MAPbBr₃ NPLs:PVK nanocomposite film was increased due to reduced self-quenching and prolonged carrier lifetime. Inverted PeLEDs with the configuration of ITO/PEIE-modified ZnO NAs/MAPbBr₃ NPLs:PVK/TFB/Au were fabricated and evaluated, using TFB as the hole transport layer. The current density of the devices containing PVK matrix was significantly suppressed compared to those without PVK. Herein, the best device revealed a max brightness of 495 cd m^-2 and a low turn-on voltage of 3.1 V that shows potential use in light-emitting applications.