Abstract
A nearly stoichiometric bismuth sulphide precipitate obtained as a by-product of the chemical deposition technique is used as a source in low-temperature vapour phase deposition of 
thin films. At relatively low deposition temperatures (
) highly polycrystalline films are formed on glass substrates, while very thin films are obtained at lower temperatures (95 - 250
). The highest photocurrent (
) is found in the first group while the highest photosensitivity (S = 56) is found in the amorphous or too thin films. XRD patterns of bismuth sulphide powder before and after 5 h deposition show its enrichment in Bi due to the enrichment in S and sulphur-rich bismuth sulphide species 
of the vapour phase. For films deposited at temperatures in the range of 290 - 380, the change in composition of the source causes different deposition rates and preferential growth of some of the bismuthinite planes (
for as-deposited powder and 
for bismuth-rich sources), compositional changes in the films (stratification) does not seem to be relevant at these temperatures. The bandgap 
of the films decreases as the deposition temperature increases from 
at 
to 1 - 1.3 eV at 
. Similar results were obtained with different sources, which indicates the stronger dependence of 
with respect to substrate temperature than with respect to the type of source.
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