Nitrogen doping in cuprous oxide films synthesized by radical oxidation at low temperature

We study nitrogen (N) doping in cuprous oxide (Cu2O) films by radical oxidation of Cu films at low temperature (500 degrees C). The morphological, crystal, and optoelectronic properties of the Cu2O have been investigated by different N-2 plasma treatment times. X-ray diffraction measurements show that Cu2O thin films grow on c-sapphire substrate with preferred (111) orientation. With increasing N-2 plasma treatment time from 0 to 40 min, the optical bandgap energy is increased from 1.69 to 2.42 eV with p-type conductivity. From the Hall measurements, it is found that the hole density is increased from 10(14) to 10(15) cm(-3) and the resistivity is decreased from 1879 to 780 Omega cm after N-2 plasma treatment. (C) 2012 Elsevier B.V. All rights reserved.