Study of the interface in n+ c-Si/p-type c-Si Heterojunctions: Role of the fluorine chemistry in the interface passivation

Investigation of n –p heterojunction solar cells obtained by depositing a n-type thin silicon films either amorphous or microcrystalline on p-type c-Si is carried out.The study is focused on the improvement of the c-Si surface and emitter layer y c-Si substrate interface.The peculiarity is the use of SiF -based plasmas for the in situ dry cleaning and passivation of the c-Si surface and for the PECVD deposition of the emitter layer that can be either amorphous (a-Si:H,F )or microcrystalline (m c-Si). The use of SiF instead of the conventional SiH results in a lower hydrogen content in the film and in a reduction of the 44 interaction of the c-Si surface with hydrogen atoms.Furthermore,the dependence of the heterojunction solar cell photovoltaic parameters on the insertion of an intrinsic buffer layer between the n-type thin silicon layer and the p-type c-Si substrate is discussed. _ 2002 Elsevier Science B.V.All rights reserved. Keywords: Heterojunctions;Thin silicon;Buffer layer