Gu Jiaming, Mou Yicheng, Ma Jianwen, Chen Haonan, Zhang Chuanxin, Wang Yuxiang, Wang Jiayu, Guo Hangwen, Shi Wu, Yuan Xiang, Jiang Xue, Ta Dean, Shen Jian, Zhang Cheng
State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, People's Republic of China.
Center for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, People's Republic of China.
Nano Lett. 2024 Aug 21;24(33):10322-10330. doi: 10.1021/acs.nanolett.4c02941. Epub 2024 Aug 12.
Light-to-electricity conversion is crucial for energy harvesting and photodetection, requiring efficient electron-hole pair separation to prevent recombination. Traditional junction-based mechanisms using built-in electric fields fail in nonbarrier regions. Homogeneous material harvesting under a photovoltaic effect is appealing but is only realized in noncentrosymmetric systems via a bulk photovoltaic effect. Here we report the realization of a photovoltaic effect by employing surface acoustic waves (SAWs) to generate zero-bias photocurrent in the conventional layered semiconductor MoSe. SAWs induce periodic modulation to electronic bands and drag the photoexcited pairs toward the traveling direction. The photocurrent is extracted from a local barrier. The separation of generation and extraction processes suppresses recombination and yields a large nonlocal photoresponse. We distinguish the acousto-electric drag and electron-hole pair separation effect by fabricating devices of different configurations. The acousto-drag photovoltaic effect, enabled by piezoelectric integration, offers an efficient light-to-electricity conversion method, independent of semiconductor crystal symmetry.
光电转换对于能量收集和光电探测至关重要，需要高效的电子 - 空穴对分离以防止复合。使用内置电场的传统基于结的机制在无障碍区域失效。在光伏效应下的均匀材料收集很有吸引力，但仅通过体光伏效应在非中心对称系统中实现。在这里，我们报告了通过利用表面声波（SAW）在传统层状半导体MoSe₂中产生零偏压光电流来实现光伏效应。SAW对电子能带进行周期性调制，并将光激发的对向传播方向拖动。光电流从局部势垒中提取。产生和提取过程的分离抑制了复合，并产生了大的非局部光响应。我们通过制造不同配置的器件来区分声电拖动和电子 - 空穴对分离效应。由压电集成实现的声拖动光伏效应提供了一种高效的光电转换方法，与半导体晶体对称性无关。
