Growth of CuInS 2 crystals from melt and their properties

CuInS2 crystals are grown from the melt with the typical compositions which are stoichiometric, In2S3 and Cu2S excess ones and the effect of the melt composition on the melt growth is examined. Large grain size crystals are grown for the melt compositions except the case of Cu2S excess one. It is found that a small amount of CuIn5S8 is precipitated in In2S3 excess crystals by forming thin film layers in the bulk. From electrical conductivity and photo-luminescence (PL) spectra of the grown crystals, predominant native point defects characterizing their semi-conducting properties are discussed. As a result, it is suggested that native vacancy and the interstitial Cu play an important roles and a tentative band-diagram is proposed. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)