TFT photodetector integrated on display panel

A thin-film transistor (TFT) photodetector for a display panel, the TFT photodetector comprising:

• an amorphous transparent substrate used as the display panel;
• a source formed of amorphous silicon or polycrystalline silicon on the transparent substrate;
• a drain formed of amorphous silicon or polycrystalline silicon, opposite to the source on the transparent substrate;
• an active layer formed between the source and the drain and having a current channel formed between the source and the drain;
• an insulating oxide film formed on the source, the drain, and the active layer;
• and
• a light receiving part formed on the insulating oxide film and configured to absorb light,
• wherein the light receiving part is isolated from the active layer by the insulating oxide film, and
• wherein when light is incident on the light receiving part, electrons migrate by tunneling through the insulating oxide film between the light receiving part and the active layer which have been excited with the insulating oxide film in between, the amount of charge in the light receiving part is changed by the migration of the electrons, a threshold voltage of the current channel is changed due to the change of the amount of charge, and photocurrent flows through the current channel due to the change of the threshold voltage.