锗锡合金中锡的迁移动力学研究

硅基光电子学将光子学技术与成熟的微电子技术融合，在光通信、光互连、光传感等领域有广泛应用前景。与CMOS工艺兼容的硅基激光器是制约硅基光电子发展的最大障碍。GeSn合金是近年研究最热门的四族半导体材料，当Sn组分达到约8%以上时，GeSn将由间接带隙转变为直接带隙材料，被认为是硅基激光器的希望。然而，要实现高组分同时保持高的晶体质量具有很大挑战。课题提出通过对外延生长的GeSn材料进行后续退火等处理方式，利用Sn在GeSn中的凝聚或者扩散过程，制备高质量高Sn组分的GeSn合金量子结构发光材料。课题将研究GeSn合金中Sn的迁移动力学过程，研究GeSn中的缺陷和应变的引入对Sn迁移的影响，探明Sn的迁移规律；掌握控制Sn迁移的有效方法；制备出高Sn组分同时晶体质量优良的GeSn直接带隙材料，研究其能带结构和发光特性；用制备的材料试制GeSn高效发光器件。

Combining the photonic technology and mature microelectronic technology together, Si-based optoelectronics has comprehensive application prospect in optical communication, optical connection and sensing. The Si-based laser compatible with the CMOS processing is still not realized. It becomes the biggest obstruction for the development of Si optoelectronics. GeSn alloy is a novel group-four semiconductor. When the Sn composition is larger than 8%, GeSn will transform from indirect to direct energy band. So, GeSn is considered as the key material for Si-based laser. But it is very difficult to grow GeSn with high Sn composition and high crystalline quality simultaneously. In this project, we propose to treat the as-grown GeSn by annealing, via the segregation or diffusion of the Sn in the GeSn alloy to form GeSn alloy luminescence material with high Sn composition and high quality. The migration dynamics of Sn in GeSn will be studied and the migration rule will be ascertained. The effect of the defect and strain to the Sn migration will be researched and the method will be obtained to control the Sn migration. According to the research, GeSn alloy with direct energy bandgap will be formed and the energy structure and luminescence properties will be studied. Using the formed GeSn alloy material, GeSn light emission devices will be fabricated.