Enhanced Responsivity of CsCu<sub>2</sub>I<sub>3</sub> Based UV Detector with CuI Buffer‐Layer Grown by Vacuum Thermal Evaporation
X. R. Zhou, Lichun Zhang, Yu Huang, Zhiying Zhou, Wenqiang Xing, Jing Zhang, Fuwang Zhou, Dengying Zhang, Fengzhou Zhao
Abstract
Abstract All‐inorganic Cu‐based perovskite Cs x Cu y I x + y thin films are deposited with vacuum thermal evaporation using CuI and CsI mixed powder with different proportion as evaporation sources. With CuI film as buffer‐layer, the as grown Cs x Cu y I x + y perovskite films only have CsCu 2 I 3 phase owing to the epitaxy on CuI layer. And the thin film quality and optoelectronic properties of CsCu 2 I 3 are also improved. Then, metal–semiconductor–metal UV detectors based on CsCu 2 I 3 films with Au interdigital electrodes are fabricated and the enhancement of photoresponse performance is investigated in detail. The peak responsivity and specific detectivity of the detector are 49.22 mA W −1 and 2.49 × 10 12 cm Hz 1/2 W −1 , which are 74 and 138 times larger than that of the device without the CuI buffer‐layer, respectively.