Conductive SiC as an intermediate layer for CSITF solar cells

Crystalline silicon thin-film solar cells (CSITF; high temperature approach) on low-cost substrates will only get their chance on the market when they can be introduced into an industrial solar cell process. Therefore, a conductive diffusion barrier intermediate layer (IL) is necessary. The most promising candidate is, in our opinion, SiC. Not just because doping with boron or phosphorous can change the electrical behavior effectively. It also matches well in thermal expansion coefficients with RBSiC (reaction-bonded) ceramics which is a very promising low-cost substrate. The passivation performance and the possibility to use the thin layer as a dopant source for an in situ back surface field are additional benefits. In this paper, we will show that the electrical conductivity of SiC can become sufficiently high with temperature treatments. We will furthermore present FTIR and SIMS measurements which would give information about the changing of bonding conditions and the distribution of the dopant boron with different deposition temperatures and annealing. (c) 2005 Elsevier B.V All rights reserved.