Optical bandgap widening of p-type Cu2O films by nitrogen doping

Abstract

We have investigated the effect of N doping into Cu2O films deposited by reactive magnetron sputtering. With increasing N-doping concentration up to 3%, the optical bandgap energy is enlarged from ∼2.1 to ∼2.5 eV with retaining p-type conductivity as determined by optical absorption and Hall effect measurements. Additionally, photoelectron spectroscopy in air measurements shows an increase in the valence and conduction band shifts with N doping. These experimental results demonstrate possible optical bandgap widening of p-type N-doped Cu2O films, which is a phenomenon that is probably associated with significant structural changes induced by N doping, as suggested from x-ray diffraction measurements.