Enhanced photoelectric performance of Cu2−xSe nanostructure by doping with In3+

Abstract

In³⁺ doped Cu_2−xSe nanostructures have been successfully synthesized on a flexible carboxyl functionalized multi-walled carbon nanotubes/polyimide (COOH-MWCNTs/PI) membrane substrate by an electrochemical codeposition method. In this work, the focus was on the effect of different In³⁺ doping concentrations upon the morphological, structural, optical and photoelectrical properties of Cu_2−xSe. Two different kinds of nanostructures, nanoflowers and nanolayers, were obtained. The crystallinity of Cu_2−xSe was improved by doping with In³⁺. The atomic ratio of Cu, Se in Cu_2−xSe nanolayers is about 1.85 : 1.00, and the atomic % of In is 1.32, confirming the presence of indium. The optical absorption intensity increased with an increase in the doping content of indium ions. However, In³⁺ had no effect upon the band gap and absorption edge. The effect of In³⁺ dopant on the photoelectric properties was investigated by photocurrent–time and current–voltage (I–V) measurements, which demonstrated that the photoelectric properties of Cu_2−xSe were improved by doping with In³⁺. This result is significant for the fabrication of optoelectronic nanomaterials and photodetectors based on In³⁺-doped Cu_2−xSe nanoflowers and nanolayers.