We describe the design of the epitaxial layers for an efficient, photon-number-determining detector that utilizes a layer of self-assembled quantum dots as an optically addressable gate in a field-effect transistor. Our design features a dedicated absorption layer where photoexcited holes are produced and directed with tailored electric fields to the quantum dots. A barrier layer ensures that the quantum dot layer is located at a two-dimensional potential minimum of the structure for the efficient collection of holes. Using quantum dots as charge traps allows us to contain the photoexcited holes in a well-defined plane. We derive an equation for a uniform size of the photon signal based on this precise geometry. Finally, we show corroborating data with well-resolved signals corresponding to different numbers of photons.
Citation: Journal of Vacuum Science and Technology B
Pub Type: Journals
HEMT heterostuctures, photon number-determining detection, quantum dots, single photon detection