Yue Lei, Tian Fuyu, Liu Ran, Li Zonglun, Li Ruixin, Li Chenyi, Li Yanchun, Yang Dongliang, Li Xiaodong, Li Quanjun, Zhang Lijun, Liu Bingbing
State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China.
Key Laboratory of Automobile Materials of MOE and School of Materials Science and Engineering, Jilin University, Changchun 130012, China.
Natl Sci Rev. 2024 Dec 3;12(1):nwae419. doi: 10.1093/nsr/nwae419. eCollection 2025 Jan.
The intentional manipulation of carrier characteristics serves as a fundamental principle underlying various energy-related and optoelectronic semiconductor technologies. However, achieving switchable and reversible control of the polarity within a single material to design optimized devices remains a significant challenge. Herein, we successfully achieved dramatic reversible p-n switching during the semiconductor‒semiconductor phase transition in BiI via pressure, accompanied by a substantial improvement in their photoelectric properties. Carrier polarity flipping was monitored by measuring the photocurrent dominated by the photothermoelectric (PTE) effect in a zero-bias two-terminal device. Accompanying the p-n transition, a switch between positive and negative photocurrents was observed in BiI, providing a feasible method to determine the conduction type of materials via photoelectric measurements. Furthermore, the combined effects of the photoconductivity and PTE mechanism improved the photoresponse and extended the detection bandwidth to encompass the optical communication waveband (1650 nm) under an external bias. The remarkable photoelectric properties were attributed to the enhanced energy band dispersion and increased charge density of BiI under pressure. These findings highlight the effective and flexible modulation of carrier properties through pressure engineering and provide a foundation for designing and implementing multifunctional logic circuits and optoelectronic devices.
对载流子特性进行有意调控是各种与能源相关的光电子半导体技术的基本原理。然而，在单一材料中实现可切换且可逆的极性控制以设计优化器件仍是一项重大挑战。在此，我们通过压力成功地在BiI的半导体-半导体相变过程中实现了显著的可逆p-n切换，同时其光电性能也有大幅提升。在零偏置双端器件中，通过测量由光热电动势（PTE）效应主导的光电流来监测载流子极性翻转。随着p-n转变，在BiI中观察到正、负光电流之间的切换，这为通过光电测量确定材料的导电类型提供了一种可行方法。此外，光电导和PTE机制的综合作用改善了光响应，并在外部偏置下将检测带宽扩展至涵盖光通信波段（1650 nm）。这些卓越的光电性能归因于压力作用下BiI增强的能带色散和增加的电荷密度。这些发现突出了通过压力工程对载流子特性进行有效且灵活的调制，并为设计和实现多功能逻辑电路及光电器件奠定了基础。
