tailieunhanh - Báo cáo hóa học: "Effect of Aspect Ratio on Field Emission Properties of ZnO Nanorod Arrays"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Effect of Aspect Ratio on Field Emission Properties of ZnO Nanorod Arrays | Nanoscale Res Lett 2008 3 303-307 DOI s11671-008-9154-0 NANO PERSPECTIVES Effect of Aspect Ratio on Field Emission Properties of ZnO Nanorod Arrays Xuemin Qian Huibiao Liu Yanbing Guo Yinglin Song Yuliang Li Received 27 June 2008 Accepted 1 August 2008 Published online 16 August 2008 to the authors 2008 Abstract ZnO nanorod arrays are prepared on a silicon wafer through a multi-step hydrothermal process. The aspect ratios and densities of the ZnO nanorod arrays are controlled by adjusting the reaction times and concentrations of solution. The investigation of field emission properties of ZnO nanorod arrays revealed a strong dependency on the aspect ratio and their density. The aspect ratio and spacing of ZnO nanorod arrays are 39 and 167 nm sample C respectively to exhibit the best field emission properties. The turn-on field and threshold field of the nanorod arrays are V m and V m respectively. Importantly the sample C shows a highest enhancement of factor b which is 2612. The result shows that an optimum density and aspect ratio of ZnO nanorod arrays have high efficiency of field emission. Keyword ZnO nanorod Arrays Field emission Aspect ratio Density Introduction ZnO is an important functional II-VI semiconductor compounds and have been extensively investigated for X. Qian Y. Song School of Physical Science and Technology Suzhou University Suzhou Jiangsu Province 215006 People s Republic of China e-mail ylsong@ X. Qian H. Liu Y. Guo Y. Li CAS Key Laboratory of Organic Solid Beijing National Laboratory for Molecular Sciences BNLMS Institute of Chemistry Chinese Academy of Sciences Beijing 100190 People s Republic of China e-mail liuhb@ their excellent optoelectronic electronic photochemical properties 1 2 . Various methods including chemical electro-chemical and physical deposition techniques have been employed to synthesize 1D ZnO nanostructures 3-5 . On the other hand the wet-chemical methods 6-8 have been used for .