Narrowband nanocomposite photodetector
AssigneeNUtech Ventures
InventorsJinsong Huang, Fawen Guo, Liang Shen
Life of this patent
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Abstract
A photodetector includes an anode that is transparent or partially transparent to light, a cathode and an active layer disposed between the anode and the cathode. The active layer includes a nanocomposite material that has a polymer blended with nanoparticles or organic electron trapping particles. The photodetector has a low dark current when not illuminated by light and has a high conductivity when illuminated by light, in which the light passes the anode and is absorbed by the active layer. The active layer has a thickness selected such that the photodetector has a narrowband spectral response.
Claims56
A method of operating a photodetector, the method comprising:
- providing a bias voltage from a power supply, and applying the bias voltage across a cathode and an anode of a photodetector, the photodetector having an active layer disposed between the cathode and the anode, the active layer comprising an electron donor material, a first electron acceptor material, and a second material that includes organic electron trapping particles;
- and
- detecting light by transmitting the light through the anode to the active layer, absorbing the light in the active layer, and increasing a current flowing through the photodetector;
- wherein the organic electron trapping particles modify energy band levels near an interface between the active layer and at least one of the anode or cathode, resulting in photoconductive gain such that a number of charges collected at the anode or cathode is larger than a number of photons detected by the photodetector.
A method of operating a photodetector, the method comprising:
- providing a bias voltage from a power supply, and applying the bias voltage across a cathode and an anode of a photodetector, the photodetector having an active layer disposed between the cathode and the anode, the active layer comprising an electron donor material, a first electron acceptor material, and a second material that includes organic charge trapping particles that electrons;
- when the photodetector is not illuminated by light, operating the photodetector in a first mode comparable to a photodiode having a rectifying Schottky contact;
- and
- when the photodetector is illuminated by light, operating the photodetector in a second mode comparable to a photoconductor having an Ohmic contact.
An apparatus comprising:
- a power supply to provide a bias voltage;
- and
- a photodetector comprising:
- an anode;
- a cathode, in which the power supply is configured to apply the bias voltage across the anode and the cathode;
- an active layer disposed between the anode and the cathode, the active layer comprising an electron donor material, a first electron acceptor material, and a second material that includes organic electron trapping particles;
- a first buffer layer disposed between the active layer and the anode;
- and
- a second buffer layer disposed between the active layer and the cathode, in which the first buffer layer blocks conduction of electrons and the second buffer layer blocks conduction of holes to reduce a dark current through the photodetector when the photodetector is not illuminated by light.
An apparatus comprising:
- a power supply to provide a bias voltage;
- and
- a photodetector array comprising:
- a plurality of anode lines that are individually selectable;
- a plurality of cathode lines that are individually selectable, in which the power supply is configured to apply the bias voltage across a selected anode line and a selected cathode line;
- and
- an active layer disposed between the anode lines and cathode lines, the active layer comprising an electron donor material, a first electron acceptor material, and a second material that includes organic trapping particles, in which each intersection of one of the anode lines and one of the cathode lines form an individually selectable photodetector.
Dependencies are inferred from the claim text.