Microstructure and lateral conductivity control of hydrogenated nanocrystalline silicon oxide and its application in a-Si:H/a-SiGe:H tandem solar cells

作者：Li, Tian-Tian; Yang, Tie; Fang, Jia; Zhang, De-Kun; Sun, Jian; Wei, Chang-Chun; Xu, Sheng-Zhi; Wang, Guang-Cai; Liu, Cai-Chi; Zhao, Ying; Zhang, Xiao-Dan^*

来源：Chinese Physics B, 2016, 25(4): 046101.

DOI：10.1088/1674-1056/25/4/046101

• gradient deposition power
• n-nc-SiOx:H films
• back reflector
• Tandem solar cells

Phosphorous-doped hydrogenated nanocrystalline silicon oxide (n-nc-SiOx:H) films are prepared via radio frequency plasma enhanced chemical vapor deposition (RF-PECVD). Increasing deposition power during n-nc-SiOx:H film growth process can enhance the formation of nanocrystalline and obtain a uniform microstructure of n-nc-SiOx:H film. In addition, in 20s interval before increasing the deposition power, high density small grains are formed in amorphous SiOx matrix with higher crystalline volume fraction (I-c) and have a lower lateral conductivity. This uniform microstructure indicates that the higher I-c can leads to better vertical conductivity, lower refractive index, wider optical band -gap. It improves the back reflection in a-Si:H/a-SiGe:H tandem solar cells acting as an n-nc-SiOx:H back reflector prepared by the gradient power during deposition. Compared with the sample with SiO, back reflector, with a constant power used in deposition process, the sample with gradient power SiO, back reflector can enhance the total short-circuit current density (J(sc)) and the initial efficiency of a-Si:H/a-SiGe:H tandem solar cells by 8.3% and 15.5%, respectively.

• 出版日期2016-4
• 单位河北工业大学; 南开大学