Wurtzite-Chalcopyrite Polytypism in CuInS2 Nanodisks

Monodisperse CuInS2 nanodisks were synthesized by heating metal chlorides and thiourea in oleylamine. X-ray diffraction showed the predominant phase to be wurtzite (hexagonal) CuInS2 instead of chalcopyrite (tetragonal) or compositionally disordered sphalerite (cubic). High-resolution transmission electron microscopy, however, revealed polytypism in the nanodisks, with the wurtzite phase interfaced with significant chalcopyrite domains.