Adjustment of the selenium amount provided during formation of CuInSe₂ thin films from the metallic precursors

Abstract

CuInSe2 (CIS) thin films were grown by selenization of sequentially evaporated Cu and In metallic precursors. The adjustment of the Selenium amount provided during the selenization process within a partially closed graphite box for film thicknesses between 0.5–2.5 μm was performed. We obtained CuInSe2 films with chalcopyrite structure and preferential orientation along the (112) direction plane. XRD patterns showed intense and narrow peaks that indicate high crystallinity corresponding to a Se amount between 120–180 mg. Direct band gap energy between 0.90–0.97 eV, depending on the Se amount and film thickness, and a high absorption coefficient (∼105 cm–1) were found. A slight improvement in the surface morphology for the optimum Se amount aforementioned was observed. The measured film resistivities varied from 0.1 Ω cm to 40 Ω cm. Thus, the structural, optical and morphological characteristics were dependent of the Se amount provided during the selenization process and after fitting of this selenium, an optimization of the CIS thin films properties and a saving of the Se consumption were achieved. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Study of the chalcopyrite Cu(In,Al)Se2 crystalline growth by selenization of different evaporated precursors ratios

“…When Cu-Se secondary phases were detected after high temperatures of selenization, they were removed by immersion of the films in aqueous solution of 0.5 M KCN at 40 1C for 2 min [10].…”

Mechanism of forming (2 2 0/2 0 4)-oriented CuInSe2 film on Al:ZnO substrate using a two-step selenization process

“…The selenization effects of Se vapor pressure and Se amount in precursors on the CIS films have been studied [26,27], high Se pressure can lead to larger grains and rough surface, but all of the CIS or CIGS films previously studied have a (1 1 2)-preferred surface orientation. Whether high Se vapor pressure used in the selenization process can result in a CIS (2 2 0/2 0 4)-preferred film or not has not been confirmed.…”

Crystallization of wide-bandgap CuAlSe2 thin films deposited on antimony doped tin oxide substrates

“…The chalcopyrite structure has been identified from the splitting of the structure lines (220)/(204) and (312)/(116) due to the tetragonal distortion (c/ a s 2). The formation of the ternary compound CuAlSe 2 is clearly identify by the (112) [25,29]. Fig.…”

“…Inside of this graphite box elemental Se has been placed together with the metallic precursor samples and loaded into a quartz tube furnace at atmospheric pressure (10 5 Pa) with flowing Ar atmosphere. The elemental Se amount has been varied over a wide range from 60 to 240 mg for 2 Â 6 cm 2 metallic samples areas [25] and final film thicknesses from 0.6 to 2 mm have been obtained after selenization.…”