Deposition of cupric oxide thin films by spin coating

Abstract

Cupric oxide thin films were deposited onto soda lime glass by spin coating and subsequent annealing of copper nitrate dissolved in a glycerol–water solvent. It was found that the solution consistently gave reproducible films with good adhesion on glass. A range of band gaps were estimated between 0·8 and 1·17 eV, showing that this material has potential as a photoabsorber. Resistivity was successfully reduced from 1·47×10⁵ to 7·02 Ω cm by doping the films with sodium. Dopant concentrations of 1 at-% gave the lowest resistivity, showing that the ideal doping is 1% or less. Film structure was found to improve with an increase in annealing time from 10 min to 1 h, although this did not have any noticeable effect on either the electrical or optical properties of the films.