Jiankun Tang, Kaixiang Liu*, Lidong Dai*, Yukai Zhuang*, Junjie Gao, Yuxue Yang, Wen Liang, Shengyun Luo, Guangcan Luo, Jing Zhang, Qinghong Li, Tengfei Wang, Rongrong Wang, Yushu Yu

Cite this article: https://doi.org/10.1016/j.cjsc.2026.101080

Publication date:

Keywords: AgBiP₂Se₆; High pressure; Structural phase transition; Electrical conductivity; Optoelectronic property

ABSTRACT

Layered ferroelectric AgBiP2Se6 has recently emerged as a promising two-dimensional semiconductor for optoelectronic conversion, whereas its pressure-regulated structural evolution, electronic transport, and broadband photoresponse remain largely unexplored. Here, we combine in situ Raman spectroscopy, synchrotron X-ray diffraction, photocurrent measurements, AC impedance spectroscopy, and first-principles calculations to establish the pressure-structure-transport-photoresponse relationship in polycrystalline layered AgBiP2Se6. Upon compression, AgBiP2Se6 undergoes an isostructural transition at approximately 7.6 GPa, followed by a semiconductor-to-metal transition near 15.3 GPa and pressure-induced amorphization above ∼28.2 GPa. These structural and electronic reconstructions give rise to a pronounced broadband enhancement of the photoresponse. Under 365 nm illumination, the photocurrent density increases from 0.0068 to 7.69 mA cm-2, while the responsivity increases from 0.11 to 128.21 mA W-1, with both parameters exhibiting an approximately 1131-fold enhancement upon compression. Enhanced photoresponse is also observed in the visible and near-infrared spectral regions. AC impedance measurements and theoretical calculations reveal that the enhanced optoelectronic performance originates from pressure-enhanced electrical conductivity, improved carrier transport, and band-gap narrowing. This work identifies pressure-driven electronic reconstruction as an effective route for optimizing broadband photoresponse in layered AgBiP2Se6 and provides insight into pressure-regulated optoelectronic behavior in two-dimensional chalcogenide semiconductors.