A coplanar hydrogenated amorphous silicon thin-film transistor for controlling backlight brightness of liquid-crystal display

摘要

We studied a coplanar hydrogenated amorphous silicon thin-film transistor (TFT) to control the backlight brightness in liquid-crystal display (LCD). This was done by designing the inverse-staggered TFT for the switching device and the coplanar TFT to absorb the illumination from backlight. We achieved the field-effect mobility of 0.3 cm~2/V s, threshold voltage of 3.6 V, and the subthreshold voltage swing of 1.3 V/d for the coplanar TFT. The TFT showed the photocurrent of ～10~(-8) A and dark current of ～10~(-11) A in the operation region of backlight for TFT-LCD. The dynamic range was 50 dB which is good enough to control the brightness of the backlight.