Zhang Zhangyuan, Zou Xuming, Xu Lei, Liao Lei, Liu Wei, Ho Johnny, Xiao Xiangheng, Jiang Changzhong, Li Jinchai
Department of Physics and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China.
Nanoscale. 2015 Jun 14;7(22):10078-84. doi: 10.1039/c5nr01924a. Epub 2015 May 15.
In this work, in order to enhance the performance of graphene gas sensors, graphene and metal oxide nanoparticles (NPs) are combined to be utilized for high selectivity and fast response gas detection. Whether at the relatively optimal temperature or even room temperature, our gas sensors based on graphene transistors, decorated with SnO2 NPs, exhibit fast response and short recovery times (∼1 seconds) at 50 °C when the hydrogen concentration is 100 ppm. Specifically, X-ray photoelectron spectroscopy and conductive atomic force microscopy are employed to explore the interface properties between graphene and SnO2 NPs. Through the complimentary characterization, a mechanism based on charge transfer and band alignment is elucidated to explain the physical originality of these graphene gas sensors: high carrier mobility of graphene and small energy barrier between graphene and SnO2 NPs have ensured a fast response and a high sensitivity and selectivity of the devices. Generally, these gas sensors will facilitate the rapid development of next-generation hydrogen gas detection.
在这项工作中，为了提高石墨烯气体传感器的性能，将石墨烯与金属氧化物纳米颗粒（NPs）结合起来用于高选择性和快速响应的气体检测。无论是在相对优化的温度下，甚至是在室温下，我们基于石墨烯晶体管并装饰有SnO2 NPs的气体传感器，当氢气浓度为100 ppm时，在50°C下表现出快速响应和短恢复时间（约1秒）。具体而言，采用X射线光电子能谱和导电原子力显微镜来探索石墨烯与SnO2 NPs之间的界面特性。通过互补表征，阐明了一种基于电荷转移和能带排列的机制，以解释这些石墨烯气体传感器的物理原理：石墨烯的高载流子迁移率以及石墨烯与SnO2 NPs之间的小能垒确保了器件的快速响应、高灵敏度和选择性。一般来说，这些气体传感器将推动下一代氢气检测的快速发展。
