Gap-Type a-Si TFTs for Backlight Sensing Application

Light-Controlled Gap-Type TFT Used for Large-Area Under-Screen Fingerprint Sensor

“…There are several photosensitive devices can be made on the same substrate of TFT, including PIN diode [4], phototransistor [5][6][7], gap-type TFTs [8][9]. We consider that gap-type TFT is the best optical device in the under-screen fingerprint sensor for its good sensitivity and low cost owing to the high photocurrent and fully TFT-compatible process [10][11].…”

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

“…Hydrogenated amorphous silicon thin-film transistors (a-Si:H TFTs) are extensively used in switching devices and peripheral driver circuits for active-matrix liquid crystal displays (AMLCDs) owing to their low cost, high uniformity over a large-area substrate, and the maturity of their fabrication process [1]- [8]. The higher photo-sensitivity of a-Si:H TFTs under illumination by visible light in comparison to amorphous-indium-gallium-zinc-oxide (a-IGZO) favors their use in optical sensors in displays, supporting X-ray image sensing, backlighting, and optical input functions [1], [3], [9], [10]. Moreover, the integration of TFT-based optical sensors into a large interactive panel can easily realize multipoint optical inputs, such as those generated using a light emitting diode (LED) pen, without the need for a complex algorithm or an additional sensing module [3].…”