Investigation of Electron-Hole Pair Production in Reduced Graphene Oxide

• Main Authors: Tsao, Rui-Wen, 曹瑞文
• Other Authors: Jian, Wen-Bin
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/56351981826981931049

碩士 === 國立交通大學 === 電子物理系所 === 102 === This experiment use reduced graphene oxide (RGO) to explore transport mechanism and use two probe measurements to measure electrical properties. The oxygen coverage of RGO could be estimated by the conductivity at room temperature. In this experiment, RGO oxygen coverage ratio is about 16%～18%. According to previous work, RGO is well described by 2D VRH in low electric field. This experiment try to study transport properties in high electric field. At 80 K, the J-E curve of RGO cannot be well described by Shklovskii expression since Shklovskii expression is derived at T = 0 K. After considering the temperature factor, the J-E curve of RGO can be fitted well. However, the J-E curve at 300 K did not follow the same model prediction. In this work, we found that the J-E curves make a transition from linear to nonlinear, power law dependences. We also determined the critical field (E_C) for the transition to be E_C≈〖10〗^6 (V/m). According to Schwinger mechanism, the electron-hole pairs is produced near the charge neutrality point. From to a series experiments and analysis, we explored the electric field behavior and compared experiments with the theoretical model. The electric field behavior shows a power law dependence that is in agreement with the theoretical prediction given by J. Schwinger.