In order to overcome the difficulties in getting bulk single crystals of Cu-based multinary compounds of high quality, we have investigated the chemical reaction involving single phase formation, the phase diagrams for bypassing the peritectic reaction, and the solid-state phase transition and the effect of VI vapor pressure on the crystal growth. The selenization or sulfurization method of a CuIn alloy is devised to grow single crystals of CuInSe2 or CuInS2. To bypass the peritectic reaction of CuGaSe2, solution growth has been performed by using a self-flux, and it is shown that large single crystals can be grown better from a CuSe solvent than from a Cu2Se solvent. In addition, a solvent of Sb2Se3 is used to grow CuInSe2 single crystals at temperatures below the solid-state phase transition. Furthermore, the melt growth under controlled VI vapor pressure is adopted to grow high-quality crystals of CuInSe2 and CuInS2. (C) 2002 Elsevier Science B.V. All rights reserved.