Wang Hailu, Xia Hui, Liu Yaqian, Chen Yue, Xie Runzhang, Wang Zhen, Wang Peng, Miao Jinshui, Wang Fang, Li Tianxin, Fu Lan, Martyniuk Piotr, Xu Jianbin, Hu Weida, Lu Wei
State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Nat Commun. 2024 Apr 29;15(1):3639. doi: 10.1038/s41467-024-47958-2.
Avalanche or carrier-multiplication effect, based on impact ionization processes in semiconductors, has a great potential for enhancing the performance of photodetector and solar cells. However, in practical applications, it suffers from high threshold energy, reducing the advantages of carrier multiplication. Here, we report on a low-threshold avalanche effect in a stepwise WSe structure, in which the combination of weak electron-phonon scattering and high electric fields leads to a low-loss carrier acceleration and multiplication. Owing to this effect, the room-temperature threshold energy approaches the fundamental limit, E ≈ E, where E is the bandgap of the semiconductor. Our findings offer an alternative perspective on the design and fabrication of future avalanche and hot-carrier photovoltaic devices.
基于半导体中的碰撞电离过程，雪崩或载流子倍增效应在提高光电探测器和太阳能电池性能方面具有巨大潜力。然而，在实际应用中，它存在高阈值能量的问题，降低了载流子倍增的优势。在此，我们报道了一种阶梯状WSe结构中的低阈值雪崩效应，其中弱电子-声子散射和高电场的结合导致了低损耗的载流子加速和倍增。由于这种效应，室温阈值能量接近基本极限，E ≈ E，其中E是半导体的带隙。我们的发现为未来雪崩和热载流子光伏器件的设计与制造提供了另一种视角。
