A Convenient and Effective Method to Deposit Low-Defect-Density nc-Si:H Thin Film by PECVD

作者：Wang, Yuwei; Liu, Hong; Shen, Wenzhong^*

来源：Nanoscale Research Letters, 2018, 13(1): 234.

DOI：10.1186/s11671-018-2641-z

• Hydrogenated nanocrystalline silicon
• PECVD
• Deposition pressure
• Ion bombardment
• Defect density

Hydrogenated nanocrystalline silicon (nc-Si:H) thin film has received a great deal of attention as a promising material for flat panel display transistors, solar cells, etc. However, the multiphase structure of nc-Si:H leads to many defects. One of the major challenges is how to reduce the defects conveniently. In this work, we developed a simple and effective method to deposit low-defect-density nc-Si:H thin film. This method is simply by tuning the deposition pressure in a high-pressure range in plasma-enhanced chemical vapor deposition (PECVD) process. Microstructures of the nc-Si:H were characterized by Raman, AFM, and SEM. Furthermore, we focused on the defect density which was the key characteristic for photovoltaic materials and achieved the defect density of 3.766 x 10(16) cm(-3).This defect density is lower than that of previous studies on the fabrication of low-defect-density nc-Si:H by other complex methods in PECVD process. The minority carrier lifetime of nc-Si:H is thus greatly improved. Moreover, we demonstrated the mechanism about the effect of deposition pressure on the ion bombardment and proved that the defect density is the key characteristic for nc-Si:H photovoltaic material.

• 出版日期2018-8-10
• 单位上海交通大学