Single-photon detector with a quantum dot and a nano-injector

A nano-resonator, comprising:

• (a) a photon absorption member;
• and
• (b) a carrier injecting member having a first layer formed on the photon absorption member, a second layer formed on the first layer, a third layer formed on the second layer, and a fourth layer formed on the third layer, and adapted for injecting carriers from the fourth layer into the photon absorption member, wherein the carrier injecting member has a horizontal dimension in a scale of nanometers,
• wherein the photon absorption member and the first to fourth layers are configured to have an energy band structure that defines a quantum dot in the second layer, such that when a photon is incident to the photon absorption member, an electron-hole pair is generated therein responsively, and one of the electron and hole of the photo-generated electron-hole pair is transported and trapped into the quantum dot in the second layer so as to enhance the concentration of the corresponding carrier therein, thereby enhancing a rate of injected carriers tunneling through the quantum dot in the second layer into the photon absorption member, wherein the injected carriers are complementary to the corresponding carrier trapped in the quantum dot.

A single-photon detector, comprising:

• (a) a multilayer structure having a photon absorption layer and a carrier mobile layer formed on the photon absorption layer, the multilayer structure configured to form a quantum well in the carrier mobile layer, the photon absorption layer adapted for generating an electron-hole pair responsive to an incident photon thereto;
• and
• (b) a nano-injector for injecting carriers, having a working end with a dimension in a scale of nanometers formed over the carrier mobile layer and configured to define a quantum dot in the carrier mobile layer directly under the nano-injector, the quantum dot being capable of trapping one type of carriers of electrons and holes while repelling the other type of carriers of electrons and holes,
• wherein in operation, an electric field is established with a lateral component and a vertical component and a stream of injected carriers flows through the working end of the nano-injector, and wherein the lateral component of the electric field causes one of the electron and hole of the photo-generated electron-hole pair to move towards the quantum dot under the nano-injector and be trapped therein, wherein the presence of the trapped carrier in the quantum dot in turn, enhances a rate of the stream of injected carriers from the working end of the nano-injector tunneling through the quantum dot into the photon absorption layer, thereby resulting in a measurable increase of a corresponding electric current, wherein the injected carriers are complementary to the corresponding carrier trapped in the quantum dot.

A single-photon detector, comprising:

• (a) a photon absorption layer for generating an electron-hole pair responsive to an incident photon thereto;
• (b) a first carrier barrier layer formed on the photon absorption layer;
• (c) a carrier mobile layer formed on the first carrier barrier layer;
• (d) a second carrier barrier layer formed on the carrier mobile layer to have a carrier barrier region and an oxidized region surrounding the carrier barrier region, the carrier barrier region having a dimension, d, in a scale of nanometers, wherein the carrier mobile layer and the first and second carrier barrier layers are configured to form a first energy band structure having a quantum well in the carrier mobile layer;
• (e) a first conductive element in contact with the second carrier barrier layer and positioned over the carrier barrier region of the second carrier barrier layer to form a nano-injector therewith for injecting electrons, which in turn, defines a quantum dot in the carrier mobile layer directly under the nano-injector which is capable of trapping the hole of the photo-generated electron-hole pair while regulating an electron flow through the nano-injector;
• (f) a second conductive element in contact with at least the photon absorption layer;
• and
• (g) a power source electrically coupled to the first conductive element and the second conductive element.