The sulfurization behaviour of co-evaporated Cu-In precursor films in dilut
ed H2S atmosphere is investigated as a function of process temperature, tim
e, post-deposition annealing and sulfur activity. The structural analysis i
s performed using X-ray diffraction including Rietveld's algorithm. Photolu
minescence spectroscopy indicates a high electronic quality for precursors
sulfurized at 400 degreesC. Lower temperatures lead to non-equilibrium effe
cts and too high process temperatures (600 degreesC) to an electronic degra
dation. At medium process temperature, a prolonged sulfurization time (6 in
stead of 3 h) leads to a drastic increase of near-band-gap states. The use
of H-2 instead of Ar as a carrier gas removes unidentified electronic state
s below 1.51 eV transition energy. (C) 2001 Elsevier Science B.V. All right
s reserved.