Thin Si films strongly doped with P and B are grown at 325 degrees C by ele
ctron cyclotron resonance chemical vapor deposition (ECR-CVD) on quartz sub
strates and Si wafers. Films deposited on quartz are microcrystalline. By a
n analysis of Hall effect data it is shown that the electrical transport in
these films is controlled by potential barriers at grain boundaries. Using
a simple barrier-limited transport model it is found that the effective in
terface defect density Q(it) increases with the doping level N-d,N-a, follo
wing a power law. A study of electron spin resonance shows that the in-grai
n mobility of electrons is much higher than the Hall mobility. At high dopi
ng levels the films grew epitaxially on Si substrates. Such films are used
as emitter layers in solar cell structures and efficiencies of 14% are demo
nstrated. (C) 2000 Elsevier Science S.A. All rights reserved.