| 학회 | 한국재료학회 |
| 학술대회 | 2013년 가을 (11/06 ~ 11/08, 제주롯데호텔) |
| 권호 | 19권 2호 |
| 발표분야 | A. 전자/반도체 재료(Electronic and Semiconductor Materials) |
| 제목 | Photochemically modified electronic properties of ZnO |
| 초록 | The photochemical tunability of charge transport mechanism in metal-oxide semiconductors is of great interest since it may offer a facile but effective semiconductor-to-metal transition, which results from photochemically modified surface electronic structure for various oxide-based device applications. Among many metal oxides, ZnO has various advantages such as low manufacturing cost, relatively stable surfaces, and great tunability of surface conductivity by post anneal process. Furthermore, the highly conductive ZnO can be applied to the transparent electrode in the visible light region due to its ultraviolet range bandgap. Absorption or emission of light in the wide photon range from the blue region to the ultraviolet region of ZnO are possible is ideal for a broad light-emitting diodes, optical filters, optical detectors, and solar cells. In spite of these merits of ZnO, the application of ZnO as the transparent electrode still requires improved electrical conductivity without transparency degradation. In this study, we exposed UV light on the ZnO surface in air to modify electronic structure and thereby to improve surface conductivity. We confirmed from experimental results that UV/air exposure led to the surface OH bond formation by H incorporation to O-vacancy sites in ZnO. This is believed to act as strong n-type donor providing excess conduction electrons in ZnO surface. The surface electronic structure of UV-exposed ZnO did not degrade visible light absorption and transparency. Regardless of the initial resistivity of ZnO samples prepared by varying RF sputtering conditions, the electrical conductivity was improved by up to x1000. The preliminary physical mechanism is also suggested to explain the origin of photochemical tunability of ZnO by UV photochemistry. |
| 저자 | 김진서, 이상연, 서형탁 |
| 소속 | 아주대 |
| 키워드 | ZnO; UV photochemistry; conductivity; electronic structure |
