William Gunnarsson1,Zhaojian Xu1,Nakita Noel1,Barry Rand1
Princeton University1
William Gunnarsson1,Zhaojian Xu1,Nakita Noel1,Barry Rand1
Princeton University1
Perovskite light-emitting diodes (LEDs) have experienced a rapid increase in efficiency over the last several years and are now regarded as promising low-cost devices for displays and communication systems. However, it is often challenging to employ ZnO, a well-studied electron transport material, in perovskite LEDs due to chemical instability at the ZnO/perovskite interface and charge injection imbalance caused by the relatively high conductivity of ZnO. In this work, we address these problems by depositing an ultrathin Al<sub>2</sub>O<sub>3</sub> interlayer at the ZnO/perovskite interface, allowing the fabrication of green-emitting perovskite LEDs with a maximum luminance of 21,815 cd/m<sup>2</sup>. Using atomic layer deposition, we can precisely control the Al<sub>2</sub>O<sub>3</sub> thickness and thus fine-tune the electron injection from ZnO, allowing us to enhance the efficiency and operational stability of our LEDs.