p-ReSe2/n-ReS2二维异质结的气相控制合成及其各向异性光电性能研究

Construction of pn junction based on two dimensional (2D) materials is one of main stream strategies for improving the integration density of devices. However, limited by the deficiency of p-type 2D semiconducting materials, the study on 2D pn junction is developing slowly. ReS2 is the youngest member among CVD-grown TMDs which is n-type semiconductor. Interestingly, ReSe2 is identified to be p-type semiconductor. More importantly, both ReS2 and ReSe2 have Re4 cluster chain in their lattice plane which renders them anisotropic properties. Therefore, this project is designed to synthesize p-ReSe2/n-ReS2 in-plane or out-of-plane heterojunctions via CVD method and then take a systematically study on the anisotropic properties, especially for (opto)electronic properties, of such a pn heterojunction. The CVD growth of 2D ReS2, ReSe2 and their heterojunction will be conducted by optimization of growth conditions including source, temperature, substrate and growth procedure, etc. Moreover, the anisotropic properties of p-ReSe2/n-ReS2 heterojunction will further be studied by electronic/optoelectronic devices and spatial/time-resolved optoelectronic measurement system. We expect that the studies on CVD growth of p-ReSe2/n-ReS2 heterojunction and its anisotropic properties would pave the way for the research and application of large-scale, anisotropic 2D pn junction based devices in future.

二维pn结是提升半导体器件集成度的重要发展方向之一。然而，由于目前二维半导体材料，尤其是p型材料的种类稀少，二维pn结的研究进展缓慢。ReS2是过渡金属硫属化合物家族中通过化学气相沉积（CVD）方法最新制备的二维n型半导体，有意思的是，其同族化合物ReSe2却为p型半导体。更为有趣的是，ReS2和ReSe2因晶体结构中存在牢固的Re4团簇链而具备各向异性的性质。本项目拟通过CVD法制备p-ReSe2/n-ReS2面间或面内异质结，并对其各向异性性能，尤其是光电性能开展系统研究。二维材料及其异质结的CVD生长，将主要通过调节生长参数，如生长源，温度，衬底以及生长流程等来实现。异质结的各向异性性能研究将基于光电子器件以及空间/时间分辨光电测试系统开展。p-ReSe2/n-ReS2异质结的CVD法可控制备与性质研究，将为未来大规模各向异性二维pn结器件的研究与应用提供基础。

二维pn结是提升半导体器件集成度的重要发展方向之一。然而，由于目前二维半导体材料，尤其是p型材料的种类稀少，二维pn结的研究进展缓慢。ReS2是n型半导体，ReSe2却为p型半导体，且ReS2和ReSe2因晶体结构中存在牢固的Re4团簇链而具备各向异性的性质。本项目通过化学气相沉积方法制备了ReS2xSe2(1-x), p-ReSe2/n-ReS2面内异质结等二维材料，并对其各项异性的光电性能进行了研究。通过精确控制生长条件，ReS2xSe2(1-x)合金的带隙从1.32 eV (ReSe2)到1.62 eV (ReS2)的连续调节，电学的属性从n型、到双极型，再到p型的连续可调，并表现出优异的各向异性光学、电学和光电特性。p-ReSe2/n-ReS2异质结器件呈现出明显的整流效应和偏振光响应。借助该合成策略，成功实现了一系列二维金属硫属化合物材料的可控合成，并研究了其光电性能。项目执行期间，累计在Adv. Mater., Adv. Funct. Mater., J. Am. Chem. Soc.等期刊上发表论文28篇，申请专利4项，指导出站博士后4名，毕业博士生3名，毕业硕士研究生7名。项目负责人荣获国家杰出青年基金、英国皇家化学会会士、高被引科学家、科技部中青年科技创新领军人才等。通过本项目的实施，为未来二维材料器件的研究与应用奠定了基础。