摘要
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 （Ic） and have a lower lateral conductivity. This uniform microstructure indicates that the higher Ic 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 SiOx back reflector, with a constant power used in deposition process, the sample with gradient power SiOx back reflector can enhance the total short-circuit current density （Jsc） and the initial efficiency of a-Si：H/a-SiGe：H tandem solar cells by 8.3% and 15.5%, respectively.
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 （Ic） and have a lower lateral conductivity. This uniform microstructure indicates that the higher Ic 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 SiOx back reflector, with a constant power used in deposition process, the sample with gradient power SiOx back reflector can enhance the total short-circuit current density （Jsc） and the initial efficiency of a-Si：H/a-SiGe：H tandem solar cells by 8.3% and 15.5%, respectively.
基金
supported by the Hi-Tech Research and Development Program of China(Grant No.2013AA050302)
the National Natural Science Foundation of China(Grant No.61474065)
Tianjin Municipal Research Key Program of Application Foundation and Advanced Technology,China(Grant No.15JCZDJC31300)
the Key Project in the Science&Technology Pillar Program of Jiangsu Province,China(Grant No.BE2014147-3)
the Specialized Research Fund for the Ph.D.Program of Higher Education,China(Grant No.20120031110039)
