范德华铁电材料4H-SnS2中的光偏振敏感晶体管效应
Light Polarization Sensitive Transistor Action in the van der Waals ferroelectric 4H-SnS2
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中文总结 AI 辅助
本研究证实4H-SnS2存在室温铁电性，基于其构建的三端晶体管展现偏振调控特性，确立该材料为偏振驱动电子与光电子技术的潜在体系。
中文摘要 AI 辅助
范德华（vdW）铁电半导体为在纳米尺度探索自发极化、电子输运、离子迁移与光生载流子产生之间的相互作用提供了独特平台。本研究通过将中心对称的2H相与极性4H相直接对比，证实了SnS2中存在室温铁电态及其对结构多型性的敏感性。拉曼光谱通过特征声子指纹区分SnS2的2H和4H多型体，压电力显微镜证实4H相存在室温铁电性，而2H相无铁电响应。在基于4H-SnS2的三端晶体管器件中，内置极化可通过静电栅压及线偏振、圆偏振光暴露显著调制，该器件展现出偏振调控的输出特性，具有明显的栅压诱导滞后响应和热激活载流子输运，证实p型半导体行为与铁电极化强耦合。其光响应同样表现出偏振辅助载流子分离、亚线性幂律标度、与特征拉曼模式相关的非单调温度响应、铁电滞后，以及对入射激光圆偏振和线偏振态的显著依赖。这些结果确立4H-SnS2为偏振驱动电子与光电子技术的潜在材料体系，包括非易失性存储器和光铁电功能器件。
英文摘要
Van der Waals (vdW) ferroelectric semiconductors provide a unique platform for exploring the interplay between spontaneous polarization, electronic transport, ion migration, and photocarrier generation at the nanoscale. Here, we establish a room-temperature ferroelectric state in SnS2 and its sensitivity to structural polytype by directly contrasting the centrosymmetric 2H-phase with the polar 4H-phase. Raman spectroscopy distinguishes the 2H and 4H polymorphs of SnS2 through their characteristic phonon fingerprints. Piezoresponse force microscopy confirms room-temperature ferroelectricity in the 4H phase, while the 2H phase exhibits no ferroelectric response. The built-in polarization in a three-terminal transistor device of the 4H-SnS2 is modulated significantly by electrostatic gating and on exposure to linear and circularly polarized light. This device reveals polarization-controlled output characteristics with distinct gate-voltage induced hysteretic response and thermally activated carrier transport, confirming p-type semiconducting behavior strongly coupled to ferroelectric polarization. The photoresponse likewise exhibits polarization-assisted carrier separation, sublinear power-law scaling, a nonmonotonic temperature response correlated with the characteristic Raman modes, ferroelectric hysteresis, and a pronounced dependence on the circular and linear polarization states of the incident laser beam. These results establish 4H-SnS2 as a promising material system for polarization-driven electronic and optoelectronic technologies, including nonvolatile memory and photoferroelectric functionalities.
