Optimized photoelectric characteristics of MAPbCl<sub>3</sub> and MAPbBr<sub>3</sub> composite perovskite single crystal heterojunction photodetector
Chao Liu, Hang Chen, Ping Lin, Haihua Hu, Qingyu Meng, Lingbo Xu, Peng Wang, Xiaoping Wu, Can Cui
Abstract
Abstract MAPbBr 3 single crystal (SC) thin layer was successfully grown on MAPbCl 3 SC substrate to form perovskite SC heterojunction. Planar structure electrodes are deposited by thermal evaporation on the surfaces of MAPbCl 3 , MAPbBr 3 , and SCs heterojunction, respectively to evaluate their photoelectric performance. The SC heterojunction device exhibits excellent unidirectional conductivity in the voltage-current curves. Meanwhile, the current–time curves prove that SC heterojunction devices can effectively utilize the advantages of MAPbCl 3 and MAPbBr 3 , possessing relatively low dark current (∼300 nA), which is comparable to the dark current of MAPbCl 3 , but very high photocurrent (∼3500 nA), which is equivalent to the photocurrent of MAPbBr 3 . Rather than the photocurrent overshot and decay occurring at the exposure of light illumination in the MAPbBr 3 device, the photocurrent is extremely stable without overshot and decay in the SC heterojunction device. The light-to-dark ratio of the SC heterojunction device is twice that of MAPbCl 3 device and three times that of MAPbBr 3 device. Furthermore, the detectivity of the heterojunction device reaches as high as <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>∼</mml:mo> <mml:mrow> <mml:mtext>7</mml:mtext> </mml:mrow> <mml:mo>×</mml:mo> <mml:mrow> <mml:mtext>1</mml:mtext> </mml:mrow> <mml:mrow> <mml:msup> <mml:mrow> <mml:mtext>0</mml:mtext> </mml:mrow> <mml:mrow> <mml:mrow> <mml:mtext>11</mml:mtext> </mml:mrow> </mml:mrow> </mml:msup> </mml:mrow> <mml:mrow> <mml:mtext> Jones</mml:mtext> </mml:mrow> </mml:math> , an order of magnitude higher than MAPbCl 3 and MAPbBr 3 . The excellent characteristics of SC heterojunction further expand the practical application prospect of perovskite materials.