The Open Crystallography Journal

2008, 1 : 10-13
Published online 2008 May 22. DOI: 10.2174/1874846500801010010
Publisher ID: TOCRYJ-1-10

P-ZnO/n-Si Photodiodes Prepared by Ultrasonic Spraying Pyrolysis Method

Lung-Chien Chen and Chun-Nan Pan
Department of Electro-optical Engineering, National Taipei University of Technology, 1, sec.3, Chung- Hsiao E. Rd., Taipei 106, Taiwan, Republic of China.

ABSTRACT

ZnO ultraviolet (UV)/visible photodiodes were fabricated. The N-In codoped p-type ZnO films were deposited on (111)-oriented silicon substrate by ultrasonic spraying pyrolysis method. It was found the photocurrent approximately 3.9􀀁10-7 A at a bias of 1 V and a photocurrent to dark current contrast ratio higher than around two orders of magnitude. The photodiodes exhibited two higher responsive regions denoted as A and B, respectively. Region A at wavelength from 400 nm to 700 nm was owing to ZnO film absorption occurring through the band-to-deep level, and region B at wavelength from 700 nm to 1000 nm was owing to Si substrate absorption occurring through the band edge.

Keywords:

Zinc oxide, spraying pyrolysis method, photodiodes.