▎ 摘　　要

NOVELTY - Single photon detecting device comprises light absorbing layer (105), charge carrier confinement layer (103), and field effect transistor (FET) (101), where the charge carrier confinement layer is arranged between the light absorbing layer and a channel layer of the FET, and a source of the FET is arranged on a same side of the channel layer of the FET as a gate of the FET and separated by a dielectric medium. The light absorbing layer is a black phosphorus material. The channel layer of the FET is a tungsten diselenide material. The dielectric medium is a hexagonal boron nitride material. The charge carrier confinement layer is a molybdenum disulfide material. The source and a drain of the FET is connected to a terminal conductor through graphene contacts. USE - The single photon detecting device is useful; in single photon detector (claimed) for detecting smallest quantum of light; for detecting room temperature; and as a pixel sensor. ADVANTAGE - The device: is simple and economical; can detect a single photon with high efficiency at room temperature; and has transparent protective layer for protecting the single photon detecting device from damage or deterioration due to environmental conditions e.g. dust and moisture. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a single photon detector comprising the single photon detecting device. DESCRIPTION OF DRAWING(S) - The figure shows the cross sectional view of the single photon detecting device. 101FET 103Charge carrier confinement layer 105Light absorbing layer