光铁电体/石墨烯器件中光伏屏蔽与缺陷介导掺杂的波长分辨控制
Wavelength-Resolved Control of Photovoltaic Screening and Defect-Mediated Doping in Photo-Ferroelectric/Graphene Devices
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中文总结 AI 辅助
该研究针对光铁电体/石墨烯器件，通过波长分辨光照解析光伏屏蔽与缺陷介导掺杂的竞争机制，实现对石墨烯电阻的调控，为器件光学编程提供指导。
中文摘要 AI 辅助
铁电体可对二维覆盖层实现大电荷掺杂，但开关型与非开关型电荷动力学的共存会使电光分析复杂化。本研究探究铁电体/石墨烯器件在365 nm与530 nm光照下的光电响应，将铁电偶极子排列的效应与外部电流通路分离开。石墨烯作为高增益传感器，将微弱的极化动力学放大为显著的电阻差异。通过解析暗态与光照下的开关型及非开关型通道，研究揭示了光伏电荷屏蔽与缺陷辅助激发间的竞争关系，该竞争关系决定了器件的静电特性。带隙以上的光照产生自由载流子，引发漏电铁电滞回线，并因动态光伏电荷屏蔽，使石墨烯在相反剩余极化态间的电阻比从290%降至15%。相比之下，530 nm光照主要通过缺陷态激发诱导铁电体内的电荷重新分布，导致石墨烯电阻变化的抑制作用显著更弱。这些结果为选择光子能量与强度提供了实用指导，可在保留剩余极化的同时调控沟道掺杂，或通过光学编程主动重构极化。
英文摘要
Ferroelectrics enable large charge doping of two-dimensional overlayers, but the coexistence of switching and nonswitching charge dynamics complicate electro-optical analysis. Here, we investigate the optoelectronic response of a ferroelectric/graphene device under 365 and 530 nm illumination, disentangling effects on ferroelectric dipole alignment from extrinsic current pathways. Graphene acts as a high-gain sensor, amplifying subtle polarization dynamics into a pronounced resistance difference. By resolving switching and nonswitching channels in dark and illuminated conditions, we reveal a competition between photovoltaic charge screening and defect-assisted excitation that governs device electrostatics. Above-band gap illumination generates free carriers that induce leaky ferroelectric hysteresis and suppress the graphene resistance ratio between opposite remanent polarization states from 290% to 15% due to dynamic photovoltaic charge screening. In contrast, 530 nm illumination primarily induces charge redistribution in ferroelectrics via defect-state excitation, leading to a significantly weaker suppression of the resistance variation of graphene. These results establish practical guidelines for selecting photon energy and intensity to either preserve remanent polarization while tuning channel doping or deliberately reconfigure polarization through optical programming.
