Enhancement of electrical properties of Al-doped ZnO thin films (AZO) by hydrogene plasma treatment

Abstract

Transparent and conductive Al-doped ZnO (AZO) films were prepared by magnetron sputtering at temperature 200^oC onto glass substrate. The films were treated with hydrogen plasma at temperatures 200^oC from 30 to 60 minutes with 200 mW/cm² power plasma. The optical, electrical and structural characteristics of the AZO coatings were analyzed as a function of the treatment time by spectrophotometry,Hall effects measurements, and X-ray diffraction. Results of X-ray diffraction analysis showed that the structure of the plasma-treated film did not change compared to that of the asdeposited film. The electrical resistivity of the AZO films decreased after H2 plasma treatment. The plasma treatment not only significantly decreased film resistivity but enhanced electrical stability as aging in air ambient. The average optical transmittance in the wave length range of 300 to 700 nm was 85%. These results were significant in application of AZO thin film as transparent electrode for a-Si:H based thin film solar cell prepared by PE-CVD method in next step.