Mechanism of CuInSe₂ nanorod formation: Cu_2-xSe phase conversion induced by indium intercalated route

Chalcopyrite CuInSe₂ nanorods have been prepared by using as-prepared Cu_2-xSe nanorods as a precursor reacted with indium chloride via a solvothermal approach. Cu_2-xSe nanorods with a diameter of about 300-500 nm, were prepared by reacting copper(i) chloride with Selenium powder and hydrazine hydrate in a mixture of NaOH and KOH. The morphology of CuInSe₂ was similar to that of the precursor Cu _2-xSe. A possible formation mechanism of the CuInSe₂ nanorods is proposed in this work. Phase conversion is believed to occur within the In³⁺ intercalated Cu_2-xSe:In during the reaction and lead to the formation of chalcopyrite phase CuInSe₂ nanorods. The structure, morphology and composition of the samples were characterized using an X-ray diffraction, transmission electron microscopy, an energy dispersive X-ray spectroscope and scanning electron microscopy.