二维PdSe2的可控制备及其偏振敏感型光电探测器应用的基础研究

Two-dimensional (2D) polarization-sensitive photodetector is regarded as one of the most promising optoelectronic device system. Nowadays, achieving polarization-sensitive photodetection with high-efficiency and long-term stability is a challenge for 2D polarization-sensitive photodetectors. PdSe2 is a newly re-discovered low-symmetry 2D material, possessing high air-stability, high mobility, wide tunable bandgap and potential high in-plane anisotropy ratio, which may very promising for polarization-sensitive photodetection. Currently, the research on 2D PdSe2 is still in its infancy. The homogenization and thickness controllable synthesis of 2D PdSe2 is an urgent issue at present, and the development of its application in polarization-sensitive photodetectors also needs further exploration. In view of the above problems, chemical vapor deposition (CVD) method will be employed to realize the uniformization and thickness controllable synthesis of 2D PdSe2, through introducing low-melting PdI2 as precursor and finely adjusting growth parameters; the in-plane anisotropic electrical and optical will be studied to establish the relationship between anisotropic properties and planar crystal orientation; the polarization modulator photoelectric measurement will be carried out to reveal the microscopic mechanism of polarized photocurrent generation, and in order to improve the performance of the 2D PdSe2 based polarization-sensitive photodetectors.

二维偏振敏感型光电探测器是一类极具发展前景的光电器件体系。当前，实现高效、稳定的偏振光电探测是二维偏振敏感型光电探测器研究的一项挑战。PdSe2是最近被重新发现的具有高稳定性、高迁移率、宽的可调带隙和潜在高平面各向异性比等特点的新型低对称结构二维材料，是一种非常具有潜力的偏振光电探测材料。目前，对二维PdSe2的研究尚处于起步阶段，实现其均匀化、厚度可控制备是当前亟待解决的重要问题，同时，开发其在偏振敏感型光电探测器中的应用也有待进一步探索。针对上述问题，本项目拟采用CVD方法，引入低熔点的PdI2作为前驱体，通过细致地调节生长参数，以实现对PdSe2均匀化、层数可控的制备；通过对其平面各向异性光、电物性研究，建立各向异性物性与平面晶向间的关联；通过系统性偏振光电探测性能测试，揭示其偏振光电流产生的微观机制，以期实现稳定高效的偏振光电探测器构筑。

二维偏振敏感型光电探测器是一类极具发展前景的光电器件体系, PdSe2材料是一种非常具有研究潜力的二维偏振光电探测材料，当前，实现其可控高质量制备是当前亟待解决的重要问题，同时，其面内各向异性物性及开发其在偏振敏感型光电探测器中的应用也有待进一步探索。本项目采用“限制空间”CVD方法实现了对二维PdSe2的可控制备；采用显微拉曼光热法，通过将偏振光沿着不同的方向探测PdSe2拉曼光谱，发现其面内各向异性热导率比为1.42；成功构筑了基于PdSe2的偏振敏感型探测器，实现了4 µs的超快速响应，该探测器还拥有自驱动、空气稳定，偏振光响应，响应度高等优势。