The structural and optical property dependence of disordered copper oxide on oxygen content

This study has investigated the optical and structural properties of reactively sputtered copper oxide. The investigated Cu to O ratio (oxygen content) spans the metal-insulator transition. Initially, the number of copper crystallites reduces and Cu2O crystallite numbers increase with increasing oxygen content, this then turns to a crystallite evolution of Cu2O to CuO as the oxygen content is increased above the nominal value for Cu2O, with no copper crystallites remaining. Along with the change in the structure, the system smoothly evolves from optically being metallic in nature to being band gap like, with increasing oxygen content.