Concurrent Improvement in Photogain and Speed of a Metal Oxide Nanowire Photodetector through Enhancing Surface Band Bending via Incorporating a Nanoscale Heterojunction
| Autor: | José Ramón Durán Retamal, Chin An Lin, Cheng-Ying Chen, Michael R. S. Huang, Chuan-Pu Liu, Jr-Hau He, Der Hsien Lien |
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| Rok vydání: | 2014 |
| Předmět: |
Materials science
Nanostructure business.industry Nanowire Oxide Photodetector Nanoparticle Heterojunction Photodetection Orders of magnitude (numbers) Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials chemistry.chemical_compound chemistry Optoelectronics Electrical and Electronic Engineering business Biotechnology |
| Zdroj: | ACS Photonics. 1:354-359 |
| ISSN: | 2330-4022 |
| Popis: | The surface effect on the photodetection of metal oxide nanostructures acting as a double-edged sword achieves ultrahigh photogain but unavoidably prolongs the response time due to slow oxygen adsorption/desorption processes. In this study, we break the compromise to enhance the UV photogain by 3 orders of magnitude as well as increase the photoresponse speed by 5 times via incorporating open-circuit p–n nanoscale heterojunctions (NHJs) by forming single-crystalline p-NiO nanoparticles on n-ZnO nanowires. This is because the formation of NHJs enhances surface band bending of ZnO nanowires, improving the spatial separation efficiency of photogenerated electrons and holes, and passivates the ZnO surfaces by minimizing the interaction of photocarriers with chemisorbed oxygen molecules. The concept using NHJs explores a new pathway toward ultrafast and supersensitive photodetection. |
| Databáze: | OpenAIRE |
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