80‐4: Amorphous Silicon Top‐Gate‐Gap TFTs for Front‐illuminated Optical Sensors

The amorphous silicon top gate‐gap TFTs are proposed for frontilluminated optical sensors in this work, which is identical to the process of standard VA TFT‐LCD arrays. The proposed top gategap TFT exhibits distinct photocurrent in both the on and off regions of Id‐Vg curve under different front‐illuminated intensities, remaining theoretically undisturbed by the bottom backlight. The length of gap has an impact on the photocurrent of top gate‐gap TFTs, where even with a real W/L of only 40μm/9μm, and the maximum dynamic range and photocurrent can achieve 128 dB and 1.86E‐7A, respectively. The photocurrent and dynamic range could be taken into account by optimized size of top gate‐gap TFTs, which could provide a new development idea for front optical sensors.