ZnO nanoparticles(NPs)play a crucial role in advancing quantum-dot light-emitting diodes(QLEDs)because of their excellent electron transport properties.While the conductivity of ZnO is determined by both the density a...ZnO nanoparticles(NPs)play a crucial role in advancing quantum-dot light-emitting diodes(QLEDs)because of their excellent electron transport properties.While the conductivity of ZnO is determined by both the density and mobility of charge carriers,a previously overlooked problem is that excessive carrier density in ZnO can lead to nonradiative Auger recombination at the quantum-dot/ZnO interface.An ideal electron transport layer should possess both high mobility and low carrier density.Here,we achieve such transport properties in ZnO NP films through operando recrystallization,a process triggered by the diffusion of Al ions from the cathode under acidic conditions.This diffusion induces the coalescence of neighboring ZnO NPs,forming defect-passivated,long-range ZnO crystals.When used as the electron transport layer in QLEDs,recrystallized ZnO NPs enhance the external quantum efficiency from 17.2%to 33.7%compared with devices with conventional ZnO electron transport layers.These findings offer valuable insights into the development of charge transport materials for high-performance optoelectronic devices.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12374375 and 12274173)the Science and Technology Development Projectof JilinProvince(20240101008JJ).
文摘ZnO nanoparticles(NPs)play a crucial role in advancing quantum-dot light-emitting diodes(QLEDs)because of their excellent electron transport properties.While the conductivity of ZnO is determined by both the density and mobility of charge carriers,a previously overlooked problem is that excessive carrier density in ZnO can lead to nonradiative Auger recombination at the quantum-dot/ZnO interface.An ideal electron transport layer should possess both high mobility and low carrier density.Here,we achieve such transport properties in ZnO NP films through operando recrystallization,a process triggered by the diffusion of Al ions from the cathode under acidic conditions.This diffusion induces the coalescence of neighboring ZnO NPs,forming defect-passivated,long-range ZnO crystals.When used as the electron transport layer in QLEDs,recrystallized ZnO NPs enhance the external quantum efficiency from 17.2%to 33.7%compared with devices with conventional ZnO electron transport layers.These findings offer valuable insights into the development of charge transport materials for high-performance optoelectronic devices.
