Room-temperature high sensitivity of multiple tunnel junctions based on single-charge photodetection

We successfully demonstrate the high stability at room temperature of a new design of single-photon detector based on multiple tunnel junctions with superior responsivity and high quantum efficiency. The single-photon detector uses one-dimensional (1D) multiple tunnel junctions (MTJs) with 12 islands and 13 tunnel junctions coupled with a silicon single-electron box. A single-electron transistor (SET) is used to read the charge state of a silicon quantum dot (Si-QD). The response of the single-photon detector (Si-QD and SET) is directly related to the photoconductivity gain in the MTJs with associated conductance steps produced by individual photocarriers. Numerical simulations confirm the high stability at room temperature of the single-photon detection. Moreover, an analytical model developed in MATLAB that takes account of the thermionic emission of charge carriers confirms the high stability of the single-photon detection at room temperature.