Photoelectrochemical Properties of the p−n Junction in and near the Surface Depletion Region of n-Type GaN

• Published in: Journal of physical chemistry. C 2010-12, Vol.114 (51), p.22727-22735
• Main Authors: Fujii, Katsushi, Ono, Masato, Iwaki, Yasuhiro, Sato, Keiichi, Ohkawa, Kazuhiro, Yao, Takafumi
• Format: Article
• Language: English
• Subjects: C: Energy Conversion and Storage
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp104403s

Photoelectrochemical water splitting is expecting a new energy source to produce hydrogen from water. The photoilluminated electrode using a uniform semiconductor single crystal has been well analyzed, but the effect of that using a structural semiconductor is still obscure. The properties of one of the structural semiconductors with a p−n junction in and near a depletion region were investigated using the samples with thin p-type layers on n-type GaN in this article. The properties were also evaluated by the calculation based on the Poisson equation. Not only the band-edge energy of a semiconductor at the semiconductor−electrolyte interface but also the length of the depletion region and the band-edge energy profile affected the photocurrent density from the evaluation. The effect of the energy profile of the depletion region is also discussed.