Photoelectric Characteristics of a-IGZO TFT under LED Illumination
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DOI: 10.25236/scmc.2019.006
Author(s)
Qingru Lu, Fan Li, Xiaodong Huang, Haiyan Xin, Hui Huang
Corresponding Author
Qingru Lu
Abstract
Amorphous Indium Gallium Zinc Oxide thin film transistor (a-IGZO TFT) with active layer size (length width) of 300um 100um is fabricated by RF magnetron sputtering. The photoelectric characteristics of the TFT illuminated by LED light of three wavelengths (405 nm, 370 nm and 310 nm) are studied by “probe method”. Results show that the value of the threshold voltage (Vth) of the TFT illuminated by LED light is smaller than that without LED illumination, and it decreases when the wavelength of LED decreases. On the contrary, Subthreshold Swing (SS) increases with the decreasing of the wavelength as the result of the increasing of the density of bound states at the interface of the device. In addition, the responsiveness (R) of the device illuminated by LED light is independent of the source-drain voltage (VDS), it is only affected by the illumination light. R decreases when the wavelength of LED light decreases, and it is constant under the illumination of the light with the specific wavelength. It is predictable that a-IGZO TFT has good photoelectric characteristics for LED light, and it has broad application prospects in sensing and photoelectric detection.
Keywords
RF Magnetron Sputtering; a-IGZO; Thin Film Transistor (TFT); Photoelectric Characteristics