聚合物辅助沉积宽带隙SiC/GaN外延薄膜研究

Due to wide-bandgap, good thermal conductivity, high-temperature resistance, and strong anti-radiation, SiC and GaN are ideal electronic materials under the harsh condition. However, both of them are hard to grow. SiC and GaN usually need themselves to induce their epitaxial growth. Unfortunately, both of them have no single crystal bulk in nature, so the expensive man-made substrates are necessary to the epitaxial growth of SiC and GaN. All these impede their application. Here, we propose a chemical solution approach for SiC/GaN heterogeneous growth, orignially based on the relatively cheap Si substrate. Ultimately, we attempt to fully investigate the electrical performance under the condition of high temperature and radiation. In addition, it is noting that there is no buffer layer used to grow these heterogeneous growth. Because the chemical solution reactions happen at the films' interface, it naturally generates a buffer-layer-like transition between the film and substrate. Simultaneously, the natural transition is helpful to reduce the stress and defect as well. In the end, the heterogeneous epitaxial films can be grown with high quality. This project not only urges the wide-bandgap semiconducting films' growth, but also contributes the electrical study of materials under harsh conditions. Our study is promising to provide potential and alternative materials in some special fields. Therefore, this study has an very important scientific values and social merits.

SiC 和GaN 具有宽带隙、高热导率、耐高温和强抗辐照等特点，因此是极端条件理想电子材料。但这两种材料非常难生长，通常需要本身块材为基底，然而SiC 和GaN 都没有天然块体材料，且人工生长基底非常昂贵，这大大阻碍了它们的应用。本项目拟发展一种廉价的聚合物辅助沉积外延生长宽带隙SiC/GaN 异质结薄膜，并研究其在极端条件下的光电子性能。这里聚合物辅助沉积溶液手段利用界面化学反应来产生完美匹配的融合过渡层，不但用于生长高质量外延薄膜，同时也有利于降低界面缺陷和应力，从而达到薄膜无缓冲层的异质外延生长。此项研究利用廉价成熟的硅基底，且不要过渡层来外延异质生长SiC/GaN 薄膜。该研究不但促进宽带隙半导体薄膜生长的实验研究，且为极端条件下此类材料的光电研究提供了基础平台。

宽带半导体薄膜在光电子领域具有广泛应用前景，如何精准控制薄膜厚度及其外延生长尤其重要。本项目主要利用化学溶液（包括聚合物辅助）生长新型宽带半导体薄膜材料，发展了新型二维半导体横向和纵向异质结、并构建各种半导体结构的性能测试与分析，对这三个方向进行研究。项目团队经过四年的研究与探索，首次提出了利用反应抑制金属离子的化学溶液法进行超薄薄膜的可控生长，从原子层面揭示了超薄薄膜生长机理，并发展了高效稳定新型光电子器件。a）利用化学法实现了新型宽带半导体的大面积生长，并在此基础上发展了利用反应抑制的化学溶液法实现了不同超薄半导体薄膜的可控生长；b）实现了溶液体系二维半导体的横向和纵向异质结的生长；c）构建了新型异质结薄膜半导体结构，并发展了多种高效光电/伏器件。并在相关领域共发表SCI通讯作者论文47篇（影响因子>20文章4篇，影响因子>10文章12篇，封面文章3篇，科普类文章2篇），其中篇JACS 2 篇， Angew Chem 2 篇，Science Adv.1篇，Nature Comm.1篇，Adv. Mater. 3篇，ACS Nano 1篇，Nano Lett 1篇，Adv. Energ. Mater.1篇。共申请专利6项，其中授权专利3项。此外，培养了一支创新能力强的年轻队伍，包括一名教授和两名副教授，博士生4名和硕士生8名。