47‐2: Photosensitive characteristics and application of photosensitive device based on TFT process

Abstract

A glass‐based TFT (thin film transistor circuit) module with ambient light detection function was designed and manufactured on the display panel, and the photoelectric characteristics of TFT photosensitive devices were measured and obtained. After the data analysis and processing, the photoelectric characteristic curves with good linearity were obtained. After algorithmically optimizing the intrinsic data, the thin‐film transistor photosensitive element achieved the same photoelectric characteristic as the silicon‐based photosensitive element. Measurements of the photoelectric characteristics of the TFT photosensitive device showed that the photoelectric performance of the sensor is repeatable and relatively undetermined. The photoelectric characteristics demonstrate the corresponding relationship of multiple direction functions. Different products show different current values under the same illumination, but the overall photoelectric characteristics still maintain the trend of multiple direction functions. In the experiment, 200 TFT photosensitive device units were connected into a set of photosensitive elements array, and placed under the ambient illumination of 0~30000 LUX. The output current range of the photosensitive array after parallel connection is 0~200 mA. The results indicate that the photoelectric characteristic of TFT photosensitive device has linear relationship after effective data processing and algorithm computing. After testing with different products, the device characterizes the ambient light with less than 5% accuracy. Therefore, the glass‐based TFT module with ambient light detection function can accurately reflect the data of ambient light, realizing the practicability of the photosensitive device based on TFT technology.