高压射频等离子体增强化学气相沉积制备高效率硅薄膜电池的若干关键问题研究

Key issues for high-efficiency silicon thin film solar cells prepared by RF-PECVD under high-pressure-depletion conditions

报道了采用高压射频等离子体增强化学气相沉积(RF-PECVD)制备高效率单结微晶硅电池和非晶硅/微晶硅叠层电池时几个关键问题的研究结果,主要包括:1)器件质量级本征微晶硅材料工艺窗口的确定及其结构和光电性能表征;2)孵化层的形成机理以及减小孵化层的有效方法;3)氢稀释调制技术对本征层晶化率分布及其对提高电池性能的作用;4)高电导、高晶化率的微晶硅p型窗口层材料的获得,及其对减小微晶硅电池p/i界面孵化层厚度和提高电池性能的作用等.在解决上述问题的基础上,采用高压RF-PECVD制备的单结微晶硅电池效率达8.16%,非晶硅/微晶硅叠层电池效率11.61%.

Our recent work on deposition and characterization of hydrogenated microcrystalline silicon （uc-Si：H） thin films and silicon thin film solar cells prepared by RF-PECVD under high-pressure-depletion conditions is summarized in this paper. Several key issues are studied in detail： 1） process windows for device-quality uc-Si：H thin films, 2） formation mechanism of amorphous silicon incubation layer and the effective methods to reduce the incubation layer thickness, 3） modification of crystalline fraction volume of intrinsic uc-Si：H layers and its influence on the device performance of uc-Si：H solar cells, 4） deposition of high conductive p-type I.tc-Si：H window layers with high crystalline fraction volume, and the influence of p-layer on the device performance. After solving the above key issues, a high efficiency of 8.16% is obtained for uc-Si：H sing-junction solar cell with intrinsic layer prepared by RF-PECVD under high-pressure-depletion conditions. When it is used as bottom cell in a-Si：H/uc-Si：H tandem solar cell, the efficiency of tandem cell reaches 11.61%.