The influences of temperature, humidity, and O2 on electrical properties of graphene FETs
The influences of temperature, humidity, and O2 on electrical properties of graphene FETs
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DOI：
10.1016/j.snb.2019.01.037
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发表时间：
2019-04-15
影响因子：
8.4
通讯作者：
Lin, Liwei
中科院分区：
文献类型：
--
作者：
Hayasaka, Takeshi;Kubota, Yoshihiro;Lin, Liwei
针对实际气敏应用中经常遇到的环境因素，研究了温度、湿度和氧气对石墨烯场效应管气敏特性的影响。实验结果和理论分析都描述了在较宽的栅极电压范围内从室温到100℃的加热石墨烯FET气体传感器的特性。结果表明，在中性点的栅压为-20V时，器件对湿度的灵敏度降低，而对O-2的灵敏度随工作温度的升高先减小后增大。用气体与石墨烯表面的物理吸附和化学吸附模型解释了这些现象。此外，由于湿度和O-2的p型掺杂效应，器件工作在空穴区域(原型器件中的大多数载流子是空穴)，与工作在电子区域的气体传感器相比，对湿度和O-2的灵敏度较低。因此，这项工作为基于石墨烯的FET气体传感器在环境空气、温度和湿度影响下的实际应用环境提供了良好的基础。
The influences of temperature, humidity, and O-2 to the gas sensing characteristics of graphene field effect transistors (FETs) have been studied as these environmental factors are often encountered in practical gas sensing applications. Both empirical results and theoretical analyses are characterized for heated graphene FET gas sensors from room temperature to 100 degrees C under a wide range of applied gate voltages. It is found that at a constant applied gate voltage of -20 V with respect to the gate voltage at the neutrality point, the sensitivity of the device to humidity decreases; while the sensitivity to O-2 decreases first, and increases afterwards as the operation temperature increases. These phenomena are explained by using the physisorption and chemisorption models between gases and the graphene surface. Furthermore, devices operate in the hole regime (the majority carrier is hole in the prototype devices) result in lower sensitivity to humidity and O-2 as compared to those results of gas sensors operating in the electron regime due to the p-type doping effects of moisture and O-2. As such, this work provides good foundations for graphene-based FET gas sensors in practical application environments under the influences of ambient air, temperature, and humidity.