Long-Term Behavior of Hydrogenated Amorphous Silicon Thin-Film Transistors Covered With Color Filters for Use in Optical Sensors

Fu-Hsing Chen; Chia-Lun Lee; Jui-Hung Chang; Wei-Sheng Liao; Chieh-An Lin; Chia-Wei Kuo; Chih-Lung Lin

doi:10.1109/ACCESS.2019.2936405

IEEE Access (Jan 2019)

Long-Term Behavior of Hydrogenated Amorphous Silicon Thin-Film Transistors Covered With Color Filters for Use in Optical Sensors

Fu-Hsing Chen,
Chia-Lun Lee,
Jui-Hung Chang,
Wei-Sheng Liao,
Chieh-An Lin,
Chia-Wei Kuo,
Chih-Lung Lin

Affiliations

Fu-Hsing Chen: Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan
Chia-Lun Lee: Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan
Jui-Hung Chang: Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan
Wei-Sheng Liao: Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan
Chieh-An Lin: Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan
Chia-Wei Kuo: AU Optronics Corporation, Hsinchu, Taiwan
Chih-Lung Lin: ORCiD; Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan

DOI: https://doi.org/10.1109/ACCESS.2019.2936405
Journal volume & issue: Vol. 7
pp. 116172 – 116178

Abstract

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This work investigates the long-term behavior of photo thin-film transistors (TFTs) that are covered with color filters and based on hydrogenated amorphous silicon (a-Si:H) technology. Based on the electrical characteristics and the optical responses of these TFTs as measured under different stress conditions, a new method for driving a photo TFT with a negative gate-source voltage is proposed to suppress the degradation of the photocurrent. The effectiveness of the newly proposed method is verified using our previously developed white-light photocurrent gating (WPCG) structure, the measurement of photocurrents, and the established models of red, green, and blue photo TFTs. An accelerated lifetime test of the fabricated circuit was carried out at 70 °C and under the illumination of ambient light for 504 hours, demonstrating that the proposed method improves the long-term reliability of optical sensors.

Published in IEEE Access

ISSN: 2169-3536 (Online)
Publisher: IEEE
Country of publisher: United States
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering
Website: https://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=6287639

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