CuIn1−x GaxS2 wide gap absorbers grown by close-spaced vapor transport

• Published in: Journal of crystal growth Vol. 270; no. 3-4; pp. 517 - 526
• Main Authors: Moudakir, T., Djessas, K., Massé, G.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-10-2004; Elsevier
• Subjects: A1. X-ray diffraction; A2. Close-spaced vapor transport; B3. Solar cells; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Vapor phase epitaxy; growth from vapor phase; A2. Close-spaced vapor transport; 81.15.Gh; B3. Solar cells; A1. X-ray diffraction; 68.55; Gallium sulfides; Stoichiometry; Inorganic compounds; Electrical conductivity; Energy dispersive spectroscopy; Transition element compounds; Thick films; Crystal growth from vapors; XRD; Experimental study; Columnar structure; Chalcopyrite; Copper sulfides; Morphology; Chemical composition; Absorption spectra; 81.15.Gh A1. X-ray diffraction; Quaternary compounds; Indium sulfides
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2004.06.057

CuIn1−xGaxS2 wide gap absorber thin films were grown by means of a low cost method using the close-spaced vapor transport principle. No high-cost vacuum apparatus is needed. From X-ray analyses, the chalcopyrite superstructure was found to be present on all the samples, except when the substrate temperatures were below 300°C. Energy dispersive spectroscopy studies showed a large quasi-stoichiometry range, corresponding to substrate temperatures between 300 and 600°C (glass substrate use limit). For initial pressures in the reactor close or equal to the atmospheric value, quasi-columnar structures were grown, with crystallite sizes of about 1μm and thicknesses of the order of 2μm. The deposition rates were about 0.05μm/min. For low pressures (<0.1bar), the deposition rates are high (up to 0.5μm/minute) and the crystallite sizes can be of several micrometers. The optical absorption showed energy gap values up to 1.65eV and rather sharp absorption fronts. The thin film resistivities are between 30 and 5000Ωcm, depending on the experimental growth conditions.