CHARACTERIZATIONS OF GALLIUM AND ARSENIC CO-DOPED ZnO THIN FILMS DEPOSITED BY PULSED LASER DEPOSITION TECHNIQUE

ABSTRACT

Gallium and arsenic doped ZnO thin films (0.1 at.%) were deposited at different temperatures by using pulsed laser deposition technique. An x-ray diffractometer was used to investigate the structural properties of the thin films. It is found that the thin films have a preferred (002) orientation, and the peak intensity of the (002) orientation increases with increasing growth temperature. Atomic force microscope was used to investigate the surface morphologies of the thin films. The grain size and roughness of the thin films depend on the growth temperature. A spectrophotometer was used to measure the transmittances of the thin films. The band gap energies of the thin films were calculated by linear fitting the sharp absorption edge of high-quality thin films. It is found that, the band gap energies of gallium and arsenic co-doped ZnO thin films are larger than the pure ZnO due to Burstein-Moss effect, and the band gap energy decreases with increasing growth temperature. A spectrometer was used to investigate the luminescent properties of the thin films. All of the thin films show near band edge emission and no deep-level emissions are observed. This is believed to be the compensation of the oxygen vacancies. Hall measurements indicate that all the thin films are n-type semiconductor and the doped thin film grown at 400°C is the most conductive and has the highest mobility.

Keywords:

• GaAs-doped ZnO
• Thin film
• PLD
• AFM
• XRD
• PL
• Hall coefficient

ACKNOWLEDGMENTS

This work was supported by Electronic Ceramics Center at DongEui University as an RIC program of ITEP under MOCIE and Busan Metropolitan City.