Enhanced photoresponse of Cu2O/ZnO heterojunction with piezo-modulated interface engineering

• Published in: Nano research 2014-06, Vol.7 (6), p.860-868
• Main Authors: Lin, Pei, Chen, Xiang, Yan, Xiaoqin, Zhang, Zheng, Yuan, Haoge, Li, Peifeng, Zhao, Yanguang, Zhang, Yue
• Format: Article
• Language: English
• Subjects: Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Chemistry and Materials Science; Condensed Matter Physics; Materials Science; Nanotechnology; Research Article; 光响应; 半导体界面; 异质结; 接口设计; 氧化亚铜; 氧化物系统; 氧化锌; 电调制
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-014-0447-6

The ability to arbitrarily regulate semiconductor interfaces provides the most effective way to modulate the performance of optoelectronic devices. However, less work has been reported on piezo-modulated interface engineering in all-oxide systems. In this paper, an enhanced photoresponse of an all-oxide Cu2O/ZnO heterojunction was obtained by taking advantage of the piezotronic effect. The illumination density-dependent piezoelectric modulation ability was also comprehensively investigated. An 18.6% enhancement of photoresponse was achieved when applying a a-0.88% compressive strain. Comparative experiments confirmed that this enhancement could be interpreted in terms of the band modification induced by interfacial piezoelectric polarization. The positive piezopotential generated at the ZnO side produces an increase in space charge region in Cu2O, thus providing an extra driving force to separate the excitons more efficiently under illumination. Our research provides a promising method to boost the performance of optoelectronics without altering the interface structure and could be extended to other metal oxide devices.