The light absorption properties of Cu2S nanowire arrays

Cu2S nanowire arrays with different morphologies were prepared by solid-gas reaction between Cu foil and mixture gas of H2S and O-2. Their microstructures were observed with XRD, TEM, and the optical properties were measured by DRS, PL and Raman. The results showed that the nanowire were Cu2S single crystal with a thin layer CuxO (x=1, 2) over the surface. The optical properties of the Cu2S nanowire arrays are related to the diameter, length, and distribution density of nanowire arrays. The thinner is the nanowire's diameter; the bigger is the absorption of the visible light, and the absorbance begun to descend within infrared band. The absorbance of nanowire arrays with bigger diameter to the infrared light was stronger than that with thinner diameter. The photoluminescence spectrum (PL) indicated that band gaps of Cu2S nanowire arrays also changed simultaneously with the nanowire arrays' structure parameters. The research demonstrated the Cu2S nanowire arrays' potential applications in the photovoltaic cell and solar-heat harvesting area.