The 4th Global Conference on Materials Science and Engineering
August 3-6, 2015 Macau, China
| ZnO ---- A promising wide-gap semiconductor for photo electronic device applications | |
| Prof. Zikang Tang | |
| Department of Physics Hong Kong University of Science and Technology, Hong Kong, China |
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ZnO is a promising semiconductor material for applications in electronics, photonics and acoustics. Its wide band gap (3.37 eV), high exciton binding energy (60 meV) and abundant resource on the planet makes ZnO very attractive over other semiconductors for ultraviolet photo-electronic device applications. However, reproducible and reliable p-type doping in pure ZnO remains to be the main current obstacle for realization of commercial applications. Among the acceptor dopants, nitrogen is believed to be the best candidate for growing p-type ZnO. However, the solubility of N in pure ZnO is very low. In order to increase the N doping level, lots of efforts were made in the past years, such as temperature modulation epitaxial technique for high level nitrogen doping, co-doping of nitrogen with other metals, such as III- and I- group elements (Al, Ga, In, Li, etc.). Despite a significant progress made, there are still a number of important physical and chemical issues that need to be resolved before ZnO can be transitioned to commercial use. In this presentation, we will review the critical issues for realization of ZnO-based devices and report our recent progress in epitaxial growth of ZnO / BeZnO single-crystal thin film system and their efficient p-type doping.
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