Self-compliance bipolar switching behavior in a ZnO NRs/CuO p-n heterojuntion with low operating current

• Main Authors: Yan-Ting Chuang, 莊彥庭
• Other Authors: Yuan-Huei Chang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/95370746763416728055

碩士 === 國立臺灣大學 === 應用物理所 === 101 === The growth and bipolar resistive switching behavior of ZnO nanorods / CuO PN heterojunction are reported in this thesis. ZnO nanorods were grown on ITO substrate by using hydrothermal method. A Cu layer was then grown on top of the ZnO nanorods and oxidized to become CuO, but before the growth of the Cu layer, the empty spaces between nanorods were filled with photo-resist to prevent current leakage. Scanning electron microscope, Photoluminescence and X-Ray diffraction were used to study the surface morphology and the crystalline structure of the sample and the results indicate that the sample have good crystalline quality and optical properties. Typical PN junction rectifying behavior was observed for the sample in the current- voltage measurement. After the forming process, the bipolar switching behavior can be clearly observed with a high/low ratio of about 10 between high resistance state and low resistance state. The operation current is very low in our device, and it can be operated at a current level of 10-7 A. In additions, current self- compliance is observed in both the set and reset processes; the current in the device decreases in both the set and rest processes. Several different kinds of electrodes were deposited on the samples to study the effect of the electrodes on the switching behavior of the devices, and the results indicate that the switching behavior is electrode-independent. A model which takes into account of the migration of vacancies in the depletion region is proposed and can explain successfully the observed experimental results.