P-type conductivity in doped and codoped ZnO thin films synthesized by RF magnetron sputtering

Abstract

N-doped and Al–N codoped ZnO thin films with different volume ratios of N2 reactive gas were deposited on plane glass substrates using the radio frequency magnetron sputtering method. The phase transition temperature and absorption edge of the ZnO powder were studied by differential scanning calorimetry at different heating rates and with Fourier transform infrared spectroscopy, respectively. The target used for the sputtering was synthesized using a palletize machine. It was sintered at 450 °C for 5 h. The X-ray diffraction results confirm that the thin films have wurtzite hexagonal structures with a very small distortion. The results indicate that the ZnO thin films have obviously enhanced transmittance of up to 80% on an average in the visible region. The Al–N codoped ZnO thin films exhibited the best p-type conductivity with a resistivity of 0.825 Ω-cm, a hole concentration of 6.55 × 1019 cm−3, and a Hall mobility of 1.25 cm2/Vs. The p-type conductivity was observed after doping and codoping of the ZnO thin film.