Highly Sensitive Photo-Sensing Element and Photo-Sensing Device Using the Same

A photo-sensing device, comprising a photo-sensing element and a switching element provided on an insulating substrate, wherein:

• said photo-sensing element comprises:
• a first electrode and a second electrode prepared by introducing phosphorous at a first density on a first semiconductor layer,
• a photoelectric conversion region prepared by introducing phosphorous at a second density, lower than said first density, on said semiconductor layer disposed between said first electrode and said second electrode, and
• a third electrode arranged above said photoelectric conversion region,
• wherein for decreasing resistance between the first and second electrodes, said third electrode to be disposed above said photoelectric conversion region in contact with said first electrode via an insulating film, but not above a region of the photo-electric conversion region in contact with the second electrode, and
• wherein said switching element comprises:
• a first electrode and a second electrode prepared by introducing phosphorous at a third density on said first semiconductor layer,
• an active region (channel) prepared by introducing phosphorous at a fourth density, lower than said third density, on said semiconductor layer disposed between said first electrode and said second electrode,
• a relaxing layer prepared by introducing phosphorous at density lower than said third density, and higher than said fourth density on said first electrode and said active region (channel), and on said second electrode and said active region (channel), and
• a third electrode disposed above said active region (channel) via an insulating film.

A photo-sensing device comprising a photo-sensing element and switching element provided on an insulating substrate, wherein:

• said photo-sensing element comprises:
• a first electrode and a second electrode prepared by introducing phosphorous at a first density on said first semiconductor layer,
• a photoelectric conversion region prepared by introducing phosphorous at a second density, lower than said first density, on said semiconductor layer disposed between said first electrode and said second electrode, and
• a third electrode arranged above said photoelectric conversion region,
• wherein said third electrode is disposed via the insulating film to be asymmetrically located above the photoelectric conversion region such that said third electrode is located above all of the photoelectric conversion region including a region of the photoelectric conversion region in contact with said first electrode,
• said switching element comprises:
• a first electrode and a second electrode prepared by introducing phosphorous at a third density on a first semiconductor layer,
• an active region (channel) prepared by introducing phosphorous at a fourth density, lower than said third density, on said semiconductor layer disposed between said first electrode and said second electrode,
• a relaxing layer prepared by introducing phosphorous at a lowly-doped density lower than said third density and higher than said fourth density on said first electrode and said active region (channel), and on said second electrode and on said active region (channel) on said first semiconductor layer, and
• a third electrode disposed above said active region (channel) via an insulating film.