Optical sensor

摘要

Disposing the light absorption layer formed in contact with a polycrystal silicon layer of a bottom gate type polycrystal silicon TFT allows a depletion layer formed between drain and channel forming regions to extend further into the inside of the light absorption layer, resulting in collection of photo carriers produced in the depletion layer into the channel forming region. The photo carriers collected into the channel forming region are subsequently collected into the source region to be output as large photocurrents by high mobility of the polycrystal silicon.