发表机构
The Ohio State University; Air Force Research Laboratory（俄亥俄州立大学; 空军研究实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究报道层状半导体CuScP2S6中单双光子吸收诱导的光电流，揭示2.35 eV带隙及位移电流机制，确立其为偏振敏感非线性光电子学多功能平台。
AI 中文摘要
层状金属硫代磷酸盐和硒代磷酸盐类材料正成为非线性光子学和光电子学应用的有前景候选材料。本文报道了 $CuScP_2S_6$ 中由单光子吸收（1PA）和双光子吸收（2PA）诱导的光电流，确立了其作为具有光电子活性的非中心对称半导体的地位。光谱分辨的1PA和2PA光响应度，结合光致发光和差分反射测量，揭示了2.35 eV的带隙、多个更高能量的带间跃迁以及亚带隙多光子激子跃迁。垂直石墨/$CuScP_2S_6$/石墨器件表现出零偏压光电流，其极性由光子能量和ab面内的光学偏振方向共同控制。这种符号依赖性，加上从线性到平方根标度的特征幂律转变，与体光伏效应（BPVE）的位移电流起源一致。这些发现确立了 $CuScP_2S_6$ 作为偏振敏感非线性光电子学多功能平台的地位。
英文摘要
The class of layered metal thiophosphates and selenophosphates are emerging as promising candidates for non-linear photonic and optoelectronic applications. Here we report one-photon absorption (1PA) and two-photon absorption (2PA) induced photocurrents in $CuScP_2S_6$, establishing it as an optoelectronically-active non-centrosymmetric semiconductor. Spectrally-resolved 1PA and 2PA photoresponsivity paired with photoluminescence and differential reflectance measurements reveal a band gap of 2.35 eV, several higher energy interband transitions, and sub-band gap multiphoton excitonic transitions. Vertical graphite/$CuScP_2S_6$/graphite devices exhibit zero-bias photocurrent with a polarity controlled by both photon energy and optical polarization orientation within the ab-plane. This sign-dependence combined with a characteristic power-law transition from linear to square-root scaling are consistent with a shift-current origin to this bulk photovoltaic effect (BPVE). These findings establish $CuScP_2S_6$ as a multi-functional platform for polarization-sensitive non-linear optoelectronics.
Comments11 pages, 9 figures
