Comprehensive study of different PECVD-deposition methods for deposition of thin intrinsic amorphous silicon for heterojunction solar cells
This work tackles the question whether a soft PECVD-deposition of intrinsic, hydrogenised, amorphous silicon (a-Si:H(i)) is really supportive for the passivation quality of the heterojunction interface between a crystalline wafer and the a-Si:H(i)-layer itself. Two PECVD-deposition methods are under investigation: i) parallel plate 13.5 MHz deposition chamber (PP-13.5 MHz), and ii) an inductively coupled plasma deposition chamber (ICP). The time dependent degradation and the thickness dependence of the passivation quality of the a-Si:H(i)- layers are discussed as an important fact to note, when the work aims to compare different a-Si:H(i)-layer deposition techniques and/or deposition parameter sets. The two different PECVD a-Si:H(i) deposition techniques are optimized and compared with the goal to find the highest possible passivation quality while reducing the layer thickness below 10 nm.