Nanothick TiO2 Channel Thin Film Transistors for UV and Gas Sensing
Nanothick TiO2 Channel Thin Film Transistors for UV and Gas Sensing
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DOI：
10.1149/2162-8777/ac04fa
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发表时间：
2021-06
影响因子：
2.2
通讯作者：
Keito Sogai;K. Saito;K. Yoshida;M. Miura;K. Kanomata;B. Ahmmad;S. Kubota;F. Hirose
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文献类型：
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作者：
Keito Sogai;K. Saito;K. Yoshida;M. Miura;K. Kanomata;B. Ahmmad;S. Kubota;F. Hirose
研究了纳米TiO 2沟道薄膜晶体管（TFT）作为紫外和气体传感器的性能。采用原子层沉积法在热氧化的n+ Si基片上沉积了TiO 2薄膜，沉积厚度为17 ~ 42 nm，沟道长度和宽度分别固定为60 μm和1 mm。在TiO 2沟道上制作了钛漏极和源极，在n+ Si衬底上制作了栅电极。纳米厚度TiO 2沟道TFT在大气中具有极高的漏极电流调制，在1.6× 10− 5 W cm− 2的紫外线照射下，波长为278 nm。这相当于2× 10 3 AW− 1的紫外灵敏度。强的漏电流调制的紫外光的解释不仅与直接吸收的紫外光子在通道中，但也与表面与大气中的气体分子的相互作用。在紫外光传感机理的研究中，我们证实了在空气、干燥空气、N2和真空等环境中，薄膜的漏电流都有很强的调制作用，这表明薄膜有可能作为黑暗中的气体传感器。本文讨论了纳米TiO 2薄膜晶体管的工作机理.
Nanothick TiO 2 channel-thin film transistors (TFTs) are examined as UV and gas sensors. The TiO 2 thin films were deposited by atomic layer deposition on thermally oxidized n+ Si substrates with deposition thicknesses from 17 to 42 nm, where the channel length and width were fixed at 60 μm and 1 mm, respectively. The titanium drain and source electrodes were fabricated on the TiO 2 channel and the n+ Si substrate was used as the gate electrode. The nanothick TiO 2-channel TFT exhibits an extremely high drain current modulation of∼ 20 μA in the atmosphere with a UV exposure of 1.6× 10− 5 W cm− 2 and a wavelength of 278 nm. This corresponds to a UV sensitivity of 2× 10 3 AW− 1. The strong drain current modulation by the UV light is explained not only with the direct absorption of the UV photons in the channel but also with the surface interactions with gas molecules in the atmosphere. In the course of the mechanism study about the UV sensing, we confirm the strong modulation of the drain current with various ambience of air, dry air, N 2, and vacuum, suggesting a possibility as the gas sensor in the dark. The operation mechanism of the nanothick TiO 2 TFT is discussed in this paper.