The influence of N2O gas addition on the properties of zinc oxide (ZnO) films grown on a-plane (11–20) sapphire (a-Al2O3) substrates was investigated, using a chemical vapor deposition method based on the reaction between dimethylzinc and high-temperature H2O produced by a catalytic H2-O2 reaction on platinum (Pt) nanoparticles. The addition of N2O was found to increase the size of the crystalline facets and to improve the crystal orientation along the c-axis. The electron mobility at 290 K was also increased to 234 cm2/Vs following the addition of N2O gas at a pressure of 3.2 × 10−3 Pa. In addition, the minimum full width at half maximum of the most intense photoluminescence peak derived from neutral donor bound excitons at 10 K decreased to 0.6 meV by the addition of N2O gas at a pressure of 3.1 × 10−2 Pa.

Improvement in the optical properties of ZnO films grown on glass substrates was investigated using a N2O-doped buffer layer inserted between the glass substrate and a ZnO film deposited by chemical vapor deposition (CVD). ZnO films were grown at 773 K using dimethylzinc (DMZn) and high-temperature H2O generated by catalytic reaction as zinc and oxygen sources, respectively. Crystal growth was enhanced for the ZnO film grown on the N2O-doped buffer layer, and the fluctuation in crystal orientation along the c-axis became less than that for a film grown directly on the glass substrate by CVD. The optical transmittance of the film in the wavelength range of 375–700 nm also increased with insertion of the buffer layer.