Seite - 84 - in Photovoltaic Materials and Electronic Devices

kept commonbetween the two setsof spectra. For the i-layer, the nominal substrate temperature and hydrogen dilution ratio were T = 200˝C and R = 10, respectively. Theoptimizedn-typea-Si:Hthicknesswasfixedat278ÅforR=50asfoundbyRTSE growth evolution studies. The depositing material fills the void space in the surface roughness layer of the underlying film. The protrusions in the surface roughness of the substrate film are coated with the depositing material, generating an interface layer associatedwith thegrowingfilm. Bruggeman effectivemedium approximation definesspectra in ε for these interfaces. 84