A Solution Processed Amorphous InGaZnO Thin-Film Transistor-Based Dosimeter for Gamma-Ray Detection and Its Reliability

• Published in: IEEE sensors journal Vol. 21; no. 9; pp. 10667 - 10674
• Main Authors: Zalte, Maruti B., Kumar, Virendra, Surya, Sandeep G., Baghini, Maryam Shojaei
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Environmental monitoring; Food irradiation; Gallium; Gamma irradiation; Gamma radiation; Gamma rays; Indium gallium zinc oxide; Ionizing radiation; Logic gates; Metal oxide semiconductors; Metal oxides; Radiation effects; Room temperature; Semiconductor devices; sensor; Sensors; solution-process; Substrates; Thin film transistors; Thin-film; Threshold voltage; transistor; Transistors; X-ray scattering; Zinc
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2021.3061955

Metal oxide semiconductors proved their usability in environmental monitoring applications and are considered successful in detecting ionizing radiation. This work reports the feasibility of solution-processed metal oxide semiconductor thin-film transistors for radiation sensing for the first time. In particular, the effects of a wide range of gamma radiation (100Gy to 10kGy) on the performance of solution-processed amorphous Indium-Gallium-Zinc-Oxide (a-IGZO) transistors are investigated. The current-voltage (IV) characterization (both output and transfer characteristics) of IGZO-TFTs before and after irradiation are obtained to study different parameters. The radiation-induced changes in TFT are mainly observed in the threshold voltage shift (<inline-formula> <tex-math notation="LaTeX">\sf \Delta ~\text{V}_{th} </tex-math></inline-formula>) and the increase of subthreshold swing. It is observed that up to a total dose of 1kGy, threshold voltage increases negatively (<inline-formula> <tex-math notation="LaTeX">\sf \Delta \,\,\text{V}_{th}= -1.8\text{V} </tex-math></inline-formula> at 1 kGy), and beyond 1 kGy, threshold voltage increases positively (<inline-formula> <tex-math notation="LaTeX">\Delta \,\,\text{V}_{\text{th}} =0.8\text{V} </tex-math></inline-formula> at 10 kGy). The XRD and AFM data of IGZO thin-film suggests minor structural and morphological changes after exposure to gamma irradiation. The corresponding sensitivity obtained with gamma irradiation is 27.78 mV/Gy (100Gy-1kGy), expressed in the threshold voltage shift. The effects of radiation-induced changes in TFTs are completely removed after storing irradiated TFTs in the vacuum at room temperature for 6 months.