An optical detector, comprising: a stacked structure including a first electrode , a photoelectric conversion layer , a second electrode , a first insulating layer , and a third electrode ; an active layer electrically coupled to one of the first electrode or the second electrode , and electrically coupled to the third electrode ; a gate insulating layer on the active layer ; and a gate electrode on the gate insulating layer , wherein: the optical detector further comprises a second insulating layer arranged between the active layer and the photoelectric conversion layer , and between the active layer and the second electrode ; the active layer is electrically coupled to the first electrode and is electrically insulated from the second electrode ; the second insulating layer is arranged on a side wall of the photoelectric conversion layer and a sidewall of the second electrode ; and the active layer is formed on an edge region of an upper surface of the first electrode , the second insulating layer , and the third electrode ; or, wherein: the active layer is electrically coupled to the second electrode and is electrically insulated from the first electrode ; and the active layer is formed on a sidewall of the second electrode , a sidewall of the first insulating layer , and the third electrode . a stacked structure including a first electrode , a photoelectric conversion layer , a second electrode , a first insulating layer , and a third electrode ; an active layer electrically coupled to one of the first electrode or the second electrode , and electrically coupled to the third electrode ; a gate insulating layer on the active layer ; and a gate electrode on the gate insulating layer , wherein: the optical detector further comprises a second insulating layer arranged between the active layer and the photoelectric conversion layer , and between the active layer and the second electrode ; the active layer is electrically coupled to the first electrode and is electrically insulated from the second electrode ; the second insulating layer is arranged on a side wall of the photoelectric conversion layer and a sidewall of the second electrode ; and the active layer is formed on an edge region of an upper surface of the first electrode , the second insulating layer , and the third electrode ; or, wherein: the optical detector further comprises a second insulating layer arranged between the active layer and the photoelectric conversion layer , and between the active layer and the second electrode ; the active layer is electrically coupled to the first electrode and is electrically insulated from the second electrode ; the second insulating layer is arranged on a side wall of the photoelectric conversion layer and a sidewall of the second electrode ; and the active layer is formed on an edge region of an upper surface of the first electrode , the second insulating layer , and the third electrode ; or, wherein: the active layer is electrically coupled to the second electrode and is electrically insulated from the first electrode ; and the active layer is formed on a sidewall of the second electrode , a sidewall of the first insulating layer , and the third electrode . <EOS>