晶硅薄膜生长和转移中表面织构的形成与陷光效应研究

Compared to traditional crystalline silicon solar cells, thin-film crystalline silicon solar cells are able to maintain high efficiency while consuming less silicon material, which makes them an important direction for the future development of crystalline silicon solar cells. This project develops a novel route to grow high-quality crystalline silicon films via periodic seed arrays fabricated on single-crystalline silicon wafers. The effects of the seed size and period on the growth and surface texture of the films will be investigated, and the growth mechanism will be revealed. The transfer process of crystalline silicon films will be explored, and the texture on the upper and lower surfaces will be formed synchronously. The analysis on the antireflection and light trapping effect of the texture on both surfaces of the films will improve the short circuit current and conversion efficiency of the solar cells. This project provides a cheap and efficient technique of fabricating high-quality crystalline silicon films, strengthens the research on the antireflection and light trapping effect of crystalline silicon films, and promotes the development of crystalline silicon solar cells.

相比于传统晶硅太阳能电池，薄膜晶硅电池在减少硅原料消耗的同时，能够保持较高的能量转换效率，是未来晶硅电池发展的重要方向。本项目在单晶硅片上构建周期性排列的籽晶阵列，外延生长高质量晶硅薄膜。研究籽晶尺寸和周期对薄膜生长和表面织构的影响，揭示薄膜生长的动力学机制。探索晶硅薄膜完整转移的工艺，并在转移过程中同步形成上下表面的织构。分析双面织构对晶硅薄膜的减反和陷光效应，提高电池的短路电流和转换效率。通过本项目的开展，能够掌握一种廉价高效的晶硅薄膜制备技术，加强对晶硅薄膜的减反和陷光效应研究，进一步推动晶硅太阳能电池的发展。

与传统晶硅太阳能电池相比，薄膜晶硅电池在减少硅原料消耗的同时，还能够保持较高的能量转换效率，是未来晶硅电池发展的重要方向。本项目进行了晶硅外延薄膜生长过程及其控制，晶硅薄膜表面织构形态控制等研究。主要进展和结果是：1、开发SiO2掩膜刻蚀法，实现了4英寸籽晶阵列衬底的制作，该方法工艺简洁、稳定、可靠，原则上无晶片尺寸限制。2、成功利用Si3N4掩膜的抗湿法刻蚀特性和抗热氧化特性制备了楔形条纹和锥形柱状籽晶阵列衬底。3、实现了从离散籽晶到连续薄膜的外延生长，同时保持连续膜与衬底之间仅通过籽晶支撑结构连接而具有空洞空间结构，从而利于外延薄膜的剥离转移操作。4、验证了外延膜的前表面或面向衬底的表面可以通过控制生长行为自发构成有序绒面结构。本项目开发的衬底技术可以应用于产业的Si薄膜外延设备，获得具有自发绒面结构的晶硅薄膜。这对实现低成本、高效、柔性晶硅太阳能电池的开发具有重要的应用价值。