Significant improvement in electronic properties of transparent amorphous indium zinc oxide through yttrium doping

¹ Faculty of Material Science and Chemistry, China University of Geosciences - 430074, China
² Department of Material Science and Engineering, National University Singapore - 21 Lower Kent Ridge Road, 117543, Singapore
³ Institute of High Performance Computing - 1 Fusionopolis Way, No. 16-16 Connexis, 138632, Singapore

^(a) msegongh@nus.edu.sg

Received: 21 November 2013
Accepted: 14 March 2014

Abstract

One big challenge in transparent conducting oxides (TCOs) is to achieve high conductivity and mobility at a low processing temperature. Although optimized conductivity has been achieved in indium zinc oxide (IZO) without doping, it is still interesting to find whether doping can improve conductivity of IZO further. In this paper, we report a low processing temperature achievement of high conductivity and mobility of IZO through yttrium (Y) doping. We found that with different Y doping levels, room temperature fabricated amorphous IZO (a-IZO) samples can be controlled to exhibit either metallic or semiconductor characteristics. Y₂O₃ is demonstrated to be an effective doping source to achieve conductivity 300% higher than the non-doped IZO sample. Anomalously improved mobility of certain Y₂O₃-doped IZO samples compared with the non-doped IZO sample is found and analyzed. Besides, a low-temperature resistivity anomaly (semiconductor metal transition) phenomenon is observed and discussed.