Abstract
CuInS2 nanoparticles (NPs) have been synthesized via thermal decomposition of metal-thiolate in high boiling temperature solvent. This method does not require toxic, unstable and expensive raw materials. Nearly monodispersed NPs with average diameter ranging from 1.8 to 2.8 nm are obtained. The NPs are found to be compositionally copper rich, Cu:In:S=1.6:1.0:1.3. They exhibit size-dependent optical properties such as photoluminescence (PL) and optical absorption, indicating quantum confinement effects. In PL spectra, the stokes-shifts (∼300 meV) from the absorption band edge and their broad PL spectra indicate that PL is ascribed to a donor-acceptor transition. These results demonstrate that chalcopyrite NPs are promising candidates for luminous and solar cell materials.
