Preparation of CuInS₂ thin films from materials grown by mechanochemical method

Abstract

Optical second harmonic generation (SHG) has been studied in TlMeX2 (Me=In,Ga, X=S,Se,Te) compounds with layered and chain crystalline structures. For layered TlInS2 and TlGaSe2, SHG signal has been observed in a range of temperatures below the point of phase transition into ferroelectric phase for which asymmetry is prominent. On the other hand, the chain TlInSe2 and TlGaTe2 have shown SHG signal at a temperature above 270 and 293K, respectively. Both the TlInSe2 and TlGaTe2 have symmetry centre at room temperature and second order optical non‐linearity is an artefact incompatible with their bulk structure. Surface structure is speculated to be responsible for SHG signal observed in these materials for the first time to our knowledge. The details of temperature behaviour of SHG in TlInSe2 and TlGaTe2 lead to a phase‐transition based model for explanation of the observed phenomenon. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Characterization of CuInS2thin films prepared from materials grown by using the mechanochemical method and their photovoltaic applications

“…The diffraction peaks corresponding to the CuS phase along with the CuInS 2 phase also appeared in the films annealed below 300 °C. 16) It has been shown that the CuS layer does not homogeneously cover the surface of the films. 13,23) Most probably, these particles are CuS crystals.…”

“…However, the source materials were grown using crystal growth from the melt, and the thin films prepared had low crystallinity. In our previous paper, CuInS 2 thin films were prepared using single-source thermal evaporation with a ternary compound grown by either the HP method 15) or the MC method 16) as source materials; the thin films were subsequently annealed in an H 2 S atmosphere. All thin films annealed above 400 °C in H 2 S atmosphere successfully formed CuInS 2 in the crystal phase.…”