Abstract
This paper deals with the structure, composition and electro-optical characteristics of n-type amorphous and microcrystalline silicon thin films produced by plasma-enhanced chemical vapour deposition in a hydrogen-helium mixture. In addition, special emphasis is given to the role that hydrogen incorporation plays in the film's properties and in the characteristics of n-type microcrystalline films presenting simultaneously optical gaps of about 2–3 eV (controlled by the hydrogen content in the film), a dark conductivity of 6·5 S cm−1 and a Hall mobility of about 0·86 cm2 V−1 s−1, the highest combined values for n-type microcrystalline silicon films, as far as we know.