Structural, Electrical, and Optical Properties of Bismuth-doped Zinc-oxide Thin Films Grown by Radio-frequency Magnetron Sputtering

Abstract

The effect of deposition temperature on the structural, optical, and electrical properties of bismuth-doped zinc-oxide (BZO) thin films was studied. The BZO thin films were prepared on sapphire substrates at various deposition temperatures by using radio-frequency magnetron sputtering. X-ray diffraction patterns showed a strong peak due to the (002) planes of Zinc-oxide (ZnO) for all samples, regardless of deposition temperature. As the deposition temperature increased, both the grain size and the film thickness increased. The optical transmittance (~ 80% at ~ 440 nm) increased rapidly with increasing wavelength and approached nearly 99% above the wavelengths of 800 nm. With increasing deposition temperature, both the electron concentration and mobility in the BZO thin films increased whereas the resistivity decreased. These results suggested that the deposition temperature is an important factor in determining the formation of high-quality BZO thin films on sapphire substrates.