Direct synthesis of indium nanoparticles and their application to prepare CuInS2 thin films and solar cells

This paper reports a simple hot-injection method to prepare monodisperse indium nanoparticles which are applied as indium sources to prepare CuInS2 thin films and solar cells. Indium nanoparticles with particle sizes of about 10 nm or even smaller are synthesized and are influenced by the stabilizing agent, reaction temperature and solvent, which can be elucidated by a burst nucleation and growth mechanism. Moreover, the inks from the indium nanoparticles are used to prepare compact and well crystallized CuInS2 (CIS) films which are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and I-V measurement. Finally, the CIS solar cells are fabricated on the basis of the CIS films, and their efficiency is about 2.08%, which can be further improved by decreasing series resistance.