Delgado-Notario Juan A, Velazquez-Perez Jesus E, Meziani Yahya M, Fobelets Kristel
Nano Lab, Salamanca University, Salamanca 37008, Spain.
Department of Electrical and Electronic Engineering, Imperial College, South Kensington Campus, London SW7 2AZ, UK.
Sensors (Basel). 2018 Feb 10;18(2):543. doi: 10.3390/s18020543.
Plasma waves in gated 2-D systems can be used to efficiently detect THz electromagnetic radiation. Solid-state plasma wave-based sensors can be used as detectors in THz imaging systems. An experimental study of the sub-THz response of II-gate strained-Si Schottky-gated MODFETs (Modulation-doped Field-Effect Transistor) was performed. The response of the strained-Si MODFET has been characterized at two frequencies: 150 and 300 GHz: The DC drain-to-source voltage transducing the THz radiation (photovoltaic mode) of 250-nm gate length transistors exhibited a non-resonant response that agrees with theoretical models and physics-based simulations of the electrical response of the transistor. When imposing a weak source-to-drain current of 5 μA, a substantial increase of the photoresponse was found. This increase is translated into an enhancement of the responsivity by one order of magnitude as compared to the photovoltaic mode, while the NEP (Noise Equivalent Power) is reduced in the subthreshold region. Strained-Si MODFETs demonstrated an excellent performance as detectors in THz imaging.
门控二维系统中的等离子体波可用于高效检测太赫兹电磁辐射。基于固态等离子体波的传感器可用作太赫兹成像系统中的探测器。对II型栅极应变硅肖特基栅调制掺杂场效应晶体管（MODFET）的亚太赫兹响应进行了实验研究。应变硅MODFET的响应在两个频率下进行了表征：150和300 GHz：250 nm栅长晶体管的太赫兹辐射（光伏模式）的直流漏源电压呈现出与晶体管电响应的理论模型和基于物理的模拟相符的非谐振响应。当施加5 μA的弱源漏电流时，发现光响应大幅增加。与光伏模式相比，这种增加转化为响应度提高了一个数量级，而在亚阈值区域噪声等效功率（NEP）降低。应变硅MODFET在太赫兹成像中作为探测器表现出优异的性能。
