Synthesis and Phase Transformation of In₂Se₃ and CuInSe₂ Nanowires

III−VI and I−III−VI semiconductors with anomalous grain boundaries have been actively studied for high efficiency photovoltaic applications. Nanowire morphology can provide a well-defined nanodomain for studying grain boundary and p−n junction physics for improving solar cell efficiency. We report the synthesis of In 2 Se 3 and CuInSe 2 single crystalline nanowires via a Au-catalyzed vapor−liquid−solid growth. Superlattice forms in In 2 Se 3 nanowires at room temperature and a reversible superlattice transformation takes place at 200 °C. Cu concentration in CuInSe 2 nanowires can be controlled, and nanowires show a dependence of crystal structure on Cu concentration.