Four different categories of rough reflecting substrates as well as a single periodic grating are incorporated and tested within n‐i‐p type amorphous silicon (a‐Si:H) solar cells. Each category is characterised by its own texture shape; dimensions were varied within the categories. Compared to flat reflecting substrates, gains in short‐circuit current density (Jsc) up to 20% have been obtained on rough reflecting plastic substrates. As long as (1) the characteristic dimensions of the textures are lower than the involved light wavelengths, (2) the textures do not present any defects i.e. as long as they do not have large craters or bumps spread over the surface, the root mean square roughness (δRMS) as well as the ratio of average feature height to average period can be used to evaluate the gain in Jsc; if each category of randomly textured substrates is considered separately, the haze factor can be used to estimate δRMS and thereby the gains in Jsc. Copyright © 2006 John Wiley & Sons, Ltd.

In the present work, several series with variation of deposition parameters such as hydrogen dilution ratio, VHF-power and plasma excitation frequency f have been extensively analyzed. Compared with`conventionala more-stable layers obtained at 200}2503C and high H dilution ratios of about 10, it was observed that electrical transport properties after light-induced degradation of layers deposited at`moderately higha temperatures (300}3503C) are equivalent but required lower H dilution ratios (between 2 and 4). As a consequence, the deposition rate of more stable layers obtained at moderately high temperatures is increased by a factor of 2. Moreover, optical gaps of a-Si:H deposited at 300}3503C are signi"cantly lower (by approx. 10 meV); furthermore, they decrease with f .