Growth of CuInSe2 nanowires without external catalyst by molecular beam epitaxy

We report the growth of CuInSe
₂
nanowires (NWs) using an evaporation process. The NWs grow on top of an underlying CuInSe
₂
polycrystalline layer that initially forms on Si(100) substrates with native SiO
₂
. Reference samples grown after removal of the native oxide do not exhibit the formation of NWs. The polycrystalline base layer has a tetragonal chalcopyrite structure and is optically active as confirmed by x-ray diffraction and photoluminescence, respectively. Transmission electron microscopy confirms the composition and atomic structure of the CuInSe
₂
NWs. Samples with NWs exhibit a reduced reflectance compared with reference samples, making them interesting for photovoltaic applications.