Zhang Tao, Zhang Guojuan, Wang Qing, Guo Siyang, Zhang Zicai, Liu Jihong, Wang Shufang, Qiao Shuang
Hebei Key Laboratory of Optic-Electronic Information and Materials, College of Physics Science and Technology, Hebei University, Baoding 071002, P. R. China.
J Phys Chem Lett. 2024 Mar 7;15(9):2511-2518. doi: 10.1021/acs.jpclett.4c00238. Epub 2024 Feb 27.
An electron transport layer (ETL) with a suitable gradient energy level can enhance electron transfer, suppress carrier recombination, and effectively improve the photoresponse of photodetectors (PDs). In this letter, a series of ITO/ZnO/CdS/MAPbI/Spiro-OMeTAD heterojunction PDs were prepared by incorporating a ZnO layer at the CdS/ITO interface upon varying the thickness from 0 to 95 nm. The optimized band arrangement in the PD results in an excellent self-powering ability and improved photoresponse. Moreover, both the photovoltaic and pyroelectric responses strongly correlate with the thickness of the ZnO layer. The PD with an optimal ZnO thin film thickness of 50 nm achieves a huge responsivity () of 1.19 × 10 V/W and detectivity () of 2.22 × 10 Jones, primarily due to the strengthened pyro-phototronic effects enabled by the dual ETL layers. In addition, the enhanced pyroelectric effect broadens the spectral range of the PD to 360-1550 nm, largely surpassing the band gap of the heterojunction.
具有合适梯度能级的电子传输层（ETL）可以增强电子转移、抑制载流子复合，并有效提高光电探测器（PD）的光响应。在本文中，通过在CdS/ITO界面处引入厚度从0到95 nm变化的ZnO层，制备了一系列ITO/ZnO/CdS/MAPbI/Spiro-OMeTAD异质结光电探测器。光电探测器中优化的能带排列产生了出色的自供电能力和改善的光响应。此外，光伏响应和热释电响应都与ZnO层的厚度密切相关。ZnO薄膜最佳厚度为50 nm的光电探测器实现了1.19×10 V/W的巨大响应度（）和2.22×10琼斯的探测率（），这主要归因于双电子传输层实现的增强热光电效应。此外，增强的热释电效应将光电探测器的光谱范围拓宽到360 - 1550 nm，大大超过了异质结的带隙。
