Electrical and Optical Properties of Ga-Doped ZnO Films Grown on Glass and Plastic Substrates by Using Plasma-Assisted Deposition

Abstract

Ga-doped zinc-oxide (GZO) lms grown under various Ga/Zn supply ratios were carefully characterized by using Hall measurements and optical transmittance measurements to investigate the electrical and the optical properties of the GZO lms on glass, polyethylene terephthalate (PET), and polycarbonate (PC) substrates. The resistivity of the GZO lms grown at 290 C on glass substrates ranged from 4 10 2 cm to 3 10 4 cm for Ga/Zn supply ratios from 0 % to 0.5 %. The growth of the GZO lms at a low temperature of 90 C was also performed on glass, PET, and PC substrates. When the Ga/Zn supply ratios were 0.05 0.1 %, the 90 C-grown GZO lms on glass substrates showed resistivities similar to those of 290 C-grown GZO lms. The 90 C-grown GZO lms on PET and PC substrates showed resistivities of 1 10 3 cm and 4 10 4 cm, respectively. The Hall carrier density was 8 1020 cm 3, which was almost the same value as that of the 90 C-grown GZO lms on glass substrates. The GZO lms on PET and PC substrates also showed visible transparency as good as that of the GZO lms on glass substrates, and the average transmittance in the visible region was higher than 85 %.