Method and apparatus for enhanced photoconductivity of semiconductor

Patent metadata

Field	Value
Publication number	US-11677040-B2
Application number	US-201916690181-A
Country	US
Kind code	B2
Filing date	Nov 21, 2019
Priority date	Nov 21, 2019
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

A photoconductor assembly includes a substrate formed of an undoped and single-crystal semiconductor material that is configured to absorb electromagnetic energy, a plurality of electrodes arranged normal to the substrate, and a power supply that applies a voltage to the electrodes for modulating the electromagnetic energy through the substrate.

First claim

What is claimed is:

1. A photoconductor assembly comprising:
a substrate formed of an undoped and single-crystal semiconductor material that is configured to reflect or absorb electromagnetic energy;
a plurality of electrodes arranged normal to the substrate;
a power supply that applies a voltage to the electrodes for modulating the electromagnetic energy through the substrate; and
a light source that generates excitation wavelengths for illuminating the substrate having energies that are equal to or greater than a band gap energy of the semiconductor material;
wherein the plurality of electrodes are arranged on opposing sides of the substrate; and
wherein the power supply is used to electrically bias the substrate and reduce a recombination rate of relevant carriers by increasing radio frequency modulation.

2. The photoconductor assembly according to claim 1 , wherein the semiconductor material has a resistivity that is greater than 5000 ohms-cm.

3. The photoconductor assembly according to claim 1 , wherein the semiconductor material is float-zone silicon or germanium.

4. The photoconductor assembly according to claim 1 further comprising an insulating layer formed on at least one of two opposing faces of the substrate.

5. The photoconductor assembly according to claim 1 , wherein the electrodes are formed of a transparent conductive film.

6. The photoconductor assembly according to claim 5 , wherein the transparent conductive film includes indium tin oxide.

7. The photoconductor assembly according to claim 1 , wherein the substrate is formed as a disc-shaped wafer.

8. The photoconductor assembly according to claim 1 , wherein the electrodes are uniformly coated on opposing surfaces of the substrate.

9. The photoconductor assembly according to claim 1 , wherein the electrodes are patterned on the substrate.

10. The photoconductor assembly according to claim 9 , wherein the electrodes are arranged in a pattern that includes at least one of striped or checkered.

11. The photoconductor assembly according to claim 1 , wherein the power supply is configured to apply a modulated voltage.

12. The photoconductor assembly according to claim 1 , wherein the wavelengths have a length in a range that is between zero and ten percent shorter than a wavelength corresponding to the band gap energy of the semiconductor material.

13. The photoconductor assembly according to claim 1 , further comprising an electromagnetic energy transmitter operatively coupled to the substrate to transmit energy to the substrate.

14. The photoconductor assembly according to claim 13 , wherein the electromagnetic energy transmitter is a microwave transmitter.

15. The photoconductor assembly according to claim 13 , wherein the electromagnetic energy transmitter is a radio frequency (RF) transmitter.

16. The photoconductor assembly according to claim 1 , further comprising a receiver operatively coupled to the substrate to receive energy from the substrate.

17. The photoconductor assembly according to claim 16 , wherein the receiver is a radio frequency (RF) receiver.

18. An electronic device comprising:
an electromagnetic energy transmitter;
a wafer that is formed of an undoped and single-crystal semiconductor material that reflects or absorbs electromagnetic energy from the electromagnetic energy transmitter;
a light source that generates excitation wavelengths for illuminating the wafer having energies that are greater than a band gap of the semiconductor material;
a plurality of electrodes arranged normal to the wafer; and
a power supply that applies a voltage to the electrodes for modulating the electromagnetic energy through the wafer;
wherein the plurality of electrodes are arranged on opposing sides of the wafer; and
wherein the power supply is used to electrically bias the substrate and reduce a recombination rate of relevant carriers by increasing radio frequency modulation.

19. The electronic device according to claim 18 , wherein the power supply is configured to apply a modulated voltage and/or the light source includes a pulsed light source or an analog intensity modulator.

20. The electronic device according to claim 18 , wherein the semiconductor material is a float-zone silicon or germanium.

21. The electronic device according to claim 18 , wherein the wavelengths have a length in a range that is between zero and ten percent shorter than a wavelength corresponding to the band gap energy of the semiconductor material.

22. The electronic device according to claim 18 , wherein the electrodes are uniformly coated on opposing sides of the wafer or patterned on at least one of the opposing sides of the wafer.

23. A method of generating electrical conductivity for a photoconductor, the method comprising:
forming a wafer of an undoped and single-crystal semiconductor material for absorbing electromagnetic energy;
arranging a plurality of electrodes normal to the wafer, wherein the plurality of electrodes are arranged on opposing sides of the wafer;
determining a depth of absorption for the wafer;
transmitting electromagnetic energy to the wafer;
illuminating the wafer based on the depth of absorption using a light source that generates excitation wavelengths having energies that are greater than a band gap of the semiconductor material; and
applying a voltage between the electrodes to modulate the electromagnetic energy through the wafer.

Assignees

• Raytheon Co

Inventors

• Frazier Gary A
• Grosse Kyle L

Classifications

• H01Q15/002

  said selective devices being reconfigurable or tunable, e.g. using switches or diodes · CPC title

• H01L31/1804

  Electricity · mapped topic

• H01L31/028

  Electricity · mapped topic

• H01L31/143

  Electricity · mapped topic

• H01L31/0216

  Electricity · mapped topic