Effect of iodine utilisation conditions on CSVT deposited CuInSe₂ films

Abstract

In this work, we investigate the effect of the carrier gas (iodine) utilisation conditions on the growth of CuInSe₂ (CIS) thin films deposited by the close spaced vapour transport technique. This study shows that the CIS films deposited at 430°C, with heated iodine and open reactor, are of high quality in structural, optical and electrical properties. Analysis by X-ray diffraction showed that these films are polycrystalline and have a chalcopyrite structure. The preferential orientation according to the plane (112) was obtained. The morphological study of these films showed that they present a compact aspect with crystallites of uniform size. The energy dispersive spectrometer analysis showed that these films are slightly copper rich. The optical and electrical studies at room temperature gave the following results: an energy gap of 1 eV, an absorption coefficient higher than 10⁵ cm^− 1, p type conductivity and a low resistivity of 0·12 Ω cm.

Keywords:

• CuInSe2
• Thin films
• CSVT
• Growth
• Iodine