Photoelectric Effects on the Photocurrent of an a-Si:H Thin Film Transistor due to the Spectral Properties of Backlight Sources

摘要

An inverted staggered-type hydrogenated amorphous-silicon thin-film transistor (a-Si:H TFT) was fabricated with a protrusion of the a-Si:H layer and its photocurrent was obtained for various backlight sources, such as a cold cathode fluorescent lamp (CCFL) and a RGB light-emitting diode (LED). Although the backlight sources had similar luminances, different photocurrents were obtained and the results were analyzed in terms of the spectral characteristics of the backlight sources instead of the luminance. The results show that the photocurrent is related to the electron-hole pairs generated in the a-Si:H layer and that the generation depends on the wavelength of the peak intensity in the spectral properties of backlight sources because the absorption of the incident light is mainly carried out at a wavelength of less than 500__600 nm. From the relationship between the backlight sources and the photocurrent of the a-Si:H TFT, it is possible to consider the effect of the backlight unit system on the photo characteristics of the TFT-LCD(liquid crystal display) panel.