Khan Md Ashfaque Hossain, Debnath Ratan, Motayed Abhishek, Rao Mulpuri V
Department of Electrical and Computer Engineering, George Mason University, Fairfax, VA 22030, USA.
N5 Sensors, Inc., Rockville, MD 20850, USA.
Sensors (Basel). 2021 Jan 17;21(2):624. doi: 10.3390/s21020624.
In this work, a TiO-coated GaN nanowire-based back-gate field-effect transistor (FET) device was designed and implemented to address the well-known cross-sensitive nature of metal oxides. Even though a two-terminal TiO/GaN chemiresistor is highly sensitive to NO, it suffers from lack of selectivity toward NO and SO. Here, a Si back gate with C-AlGaN as the gate dielectric was demonstrated as a tunable parameter, which enhances discrimination of these cross-sensitive gases at room temperature (20 °C). Compared to no bias, a back-gate bias resulted in a significant 60% increase in NO response, whereas the increase was an insignificant 10% in SO response. The differential change in gas response was explained with the help of a band diagram, derived from the energetics of molecular models based on density functional theory (DFT). The device geometries in this work are not optimized and are intended only for proving the concept.
在这项工作中，设计并实现了一种基于二氧化钛包覆氮化镓纳米线的背栅场效应晶体管（FET）器件，以解决金属氧化物众所周知的交叉敏感特性问题。尽管两终端二氧化钛/氮化镓化学电阻对一氧化氮高度敏感，但它对一氧化氮和二氧化硫缺乏选择性。在此，以碳-氮化铝镓作为栅极电介质的硅背栅被证明是一个可调参数，它能在室温（20°C）下增强对这些交叉敏感气体的辨别能力。与无偏置相比，背栅偏置使一氧化氮响应显著增加60%，而二氧化硫响应的增加仅为微不足道的10%。借助基于密度泛函理论（DFT）的分子模型能量学推导的能带图，解释了气体响应的差异变化。这项工作中的器件几何结构未进行优化，仅用于证明概念。
