Properties Of Interfaces In Amorphous Crystalline Silicon Heterojunctions PDF Download

The main focus of this work is the study of interfaces in amorphous/crystalline silicon (a-Si:H/c-Si) heterostructures, especially the investigation of the a-Si:H/c-Si heterointerface's electronic quality and its effect on the consecutive a-Si:H/c-Si heterojunction (HJ) solar cell fabrication. c-Si based solar cells have the potential for achieving high conversion efficiencies, but the standard simple fabrication processes lead to medium module efficiencies. Thin-film Si based technologies offer the prospect of low-cost fabrication but yield lower efficiencies. a-Si:H/c-Si HJ solar cells combine the advantages of both technologies, i.e., the high efficiency potential of c-Si and the low fabrication cost of a-Si:H. In this way the c-Si cost becomes reasonable because it is possible to use very thin wafers to produce highly efficient solar cells. The electronic quality of the heterostructure interface was evaluated experimentally with photogenerated carrier lifetime measurements. In this study, carrier recombination at the interface is the step limiting photogenerated carriers' lifetime. In the theoretical part of this work, c-Si surface recombination is modeled by considering for the first time the amphoteric nature of Si dangling bonds. For this, a model previously established for bulk a-Si:H recombination, is extended to the description of the c-Si surface recombination through amphoteric defects. Its differences and similarities compared to existing interface recombination models are discussed. This new model is currently the simplest that allows an understanding of the largest set of experimentally observed behaviors of passivation layers on c-Si. The potential of the model's applicability to passivation by silicon dioxide (SiOsub2/sub) and silicon nitride (SiNsubx