8-10 June 2016
Asia/Bangkok timezone

Electrical Property of Titanium Doped Gallium Phosphide Thin Film Deposited by Asymmetric Bipolar Pulsed-DC Magnetron Sputtering for Intermediate Band Solar Cell (IBSC)

Not scheduled
15m
Poster presentation Surface, Interface and Thin Films

Speaker

Mr Tanachai Ponken (Department of Physics, Faculty of Science, Khon Kean University, 40002, Thailand)

Description

Ti-Ga-P thin films were prepared by an asymmetric bipolar pulsed-dc magnetron sputtering technique using GaP:Ti targets onto glass substrate at 300°C in an argon atmosphere. The sputtering targets contained GaP powder compacted between metallic titanium (Ti) sheets, at the surface area ratio GaP:Ti of 1:1, 2:1, and 5:1. The crystal structure, electrical sheet resistance, and surface morphology of the as-deposited films were analyzed by X-ray diffraction (XRD), the linear 4 point probe technique, and atomic force microscopy (AFM), respectively. The XRD patterns showed that the as-deposited films are polycrystalline of cubic zinc blend structure. The sheet resistance at room temperature were 0.97E+1 and 6.02E+1 Ω/cm2 for the films obtained from the GaP:Ti_1:1 and GaP:Ti_2:1 targets, at the deposition time of 60 minutes. The film obtained from the GaP:Ti_2:1 target exhibited the sheet resistance which exponentially increases with decreasing temperature in the range of 180K – 50 K, indicating semiconducting behavior. On the other hand, the film obtained from the GaP:Ti_1:1 target showed the sheet resistance which is independent on the decreasing temperature, suggesting a rather metallic behavior. AFM images indicated the formation of metallic Ti clusters within crystalline grains of the films. The cluster density appears higher in the films obtained from the GaP:Ti_1:1 target than those obtained from the GaP:Ti_2:1 target. The results of this study suggest that it is possible to dope Ti into GaP host semiconductor by co-sputtering of GaP and Ti. However, above a certain concentration of Ti, the formation of metallic titanium inclusions within crystalline grains is promoted, leading to metallic like electrical behavior.

Primary author

Mr Tanachai Ponken (Department of Physics, Faculty of Science, Khon Kean University, 40002, Thailand)

Co-author

Dr Thanusit Burinprakhon (Department of Physics, Faculty of Science, Khon Kean University, 40002, Thailand)

Presentation materials

There are no materials yet.