AI 中文总结
该研究以PtSe₂为对象，通过单轴拉伸应变调控其光电流，明确了应变可通过形变势调节SOC带隙，实现可重构红外偏振探测，为红外光电子学提供新调控思路。
AI 中文摘要
半金属型贵金属二硫化物是红外光电子学的有前途材料，但其非线性光学响应的起源与可调性仍知之甚少。本文展示了在柔性聚酰亚胺衬底上生长的多晶PtSe₂薄膜中光拖光电流的原位机械调控。通过单轴拉伸应变下的偏振分辨中红外光电流光谱，我们观察到电阻率、光电导性和与螺旋度相关的非线性光电流存在显著的应变依赖变化。该光谱响应与自旋轨道耦合（SOC）诱导的K点附近带隙的光激发一致。我们开发了理论框架，将光电流主要归因于光子动量对称性破缺导致的光拖效应。应变通过形变势调控SOC诱导带隙，从而改变光电流的大小和偏振依赖性。这些结果确立了机械应变作为可重构红外偏振探测的一种途径。
英文摘要
Semi-metallic noble-metal dichalcogenides are promising materials for infrared optoelectronics, yet the origin and tunability of their nonlinear optical responses remain poorly understood. Here, we demonstrate in-situ mechanical control of photon-drag photocurrents in polycrystalline PtSe$_2$ thin films grown on flexible polyimide substrates. Using polarization-resolved mid-infrared photocurrent spectroscopy under uniaxial tensile strain, we observe pronounced strain-dependent changes in resistivity, photoconductivity, and helicity-dependent nonlinear photocurrents. The spectral response is consistent with optical excitations across the spin-orbit-coupling-induced (SOC) band gap near the K point. We develop a theoretical framework attributing the photocurrent primarily to photon-drag induced by photon-momentum symmetry breaking. Strain modifies its magnitude and polarization dependence through deformation potentials that tune the SOC-induced band gap. These results establish mechanical strain as a route toward reconfigurable infrared polarization detection.
