Thyristor Radiation Detector Array and Applications Thereof

• US 20100123121A1
• Filed: 03/18/2008
• Published: 05/20/2010
• Est. Priority Date: 03/18/2008
• Status: Active Grant

• Current Assignee: OPEL Solar, Inc. (POET Technologies Inc.), University of Connecticut (State of Connecticut)
• Original Assignee: OPEL Solar, Inc. (POET Technologies Inc.)
• Inventors: Taylor, Geoff W.
• Granted Patent: US 8,080,821 B2
• Time in Patent Office: Days
• US Class Current: 257/21
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G01S 3/781 Details
• CPC Class Codes: G01S 3/784 using a mosaic of detectors
• CPC Class Codes: H01L 31/035236 Superlattices; Multiple quantum well structures
• CPC Class Codes: H01S 5/0265 Intensity modulators intra-cavity modulators H01S5/0625

Abstract

An array of thyristor detector devices is provided having an epitaxial growth structure with complementary types of modulation doped quantum well interfaces located between a P+ layer and an N+ layer. The thyristor detector devices operate over successive cycles that each include a sequence of two distinct modes: a setup mode and a signal acquisition mode. During the setup mode, the n-type quantum well interface and/or the p-type quantum well interface is(are) substantially emptied of charge. During the signal acquisition mode, photocurrent is generated by the thyristor detector device in response to the absorption of incident electromagnetic radiation therein, which can induce the thyristor detector device to switch from an OFF state to an ON state. The OFF/ON state of the thyristor detector device produces an output digital electrical data that corresponds to the amount of incident radiation absorbed by the thyristor detector device during the signal acquisition mode of the current cycle. In the preferred embodiment, the array of thyristor detector devices is part of a monolithic integrated circuit that includes additional electronic circuitry and/or optical components. Moreover, the array of thyristor detector devices is preferably part of a monolithic integrated circuit for high angular resolution laser irradiation detection.

Claims

1. A radiation detector comprising:

an array of thyristor devices each including complementary first-type and second-type modulation doped quantum well interfaces that are formed on a common substrate and that are spaced apart from one another, wherein each given thyristor device is adapted to operate in each of the following modes;

i) a setup mode whereby charge is emptied from said first-type and second-type modulation doped quantum well interfaces for said given thyristor device; and

ii) a signal acquisition mode whereby electromagnetic radiation within a predetermined wavelength is absorbed by said given thyristor device over a time period producing photocurrents that selectively switch said given thyristor device from an OFF state to an ON state in accordance with power of the electromagnetic radiation within the predetermined wavelength range that is received at said given thyristor device.

2. A radiation detector according to claim 1, wherein:

each given thyristor device is adapted to perform a sequence of cycles, each cycle including said setup mode and said signal acquisition mode.

3. A radiation detector according to claim 2, wherein:

in the event that said given thyristor device switches to said ON state during the signal acquisition mode of a given cycle, said given thyristor device is switched to the OFF state in the setup mode of the next cycle.

4. A radiation detector according to claim 1, wherein:

each given thyristor device comprises an anode terminal, injector control terminals coupled to corresponding complementary modulation doped quantum well interfaces, and a cathode terminal.

5. A radiation detector according to claim 4, further comprising:

bias load circuitry operably coupled to a current path between said anode terminal and said cathode terminal.

6. A radiation detector according to claim 5, wherein:

said bias load circuitry is selectively coupled to the current path between said anode terminal and said cathode terminal in the signal acquisition mode and selectively isolated from the current path between said anode terminal and said cathode terminal in the setup mode.

7. A radiation detector according to claim 6, further comprising:

first bias current source circuitry operably coupled to at least one of said complementary modulation doped quantum well structures in the setup mode.

8. A radiation detector according to claim 7, further comprising:

second bias current source circuitry operably coupled to at least one of said complementary modulation doped quantum well structures in the signal acquisition mode for adjusting sensitivity of said given thyristor device.

9. A radiation detector according to claim 8, wherein:

the array of thyristor devices, said bias load circuitry, said first bias current source circuitry, and said second bias current source circuitry are all realized by devices integrally formed on a common substrate.

10. A radiation detector according to claim 9, wherein:

said devices are formed from an epitaxial structure deposited on the common substrate.

11. A radiation detector according to claim 10, wherein:

said epitaxial structure comprises a III-V material system.

12. A radiation detector according to claim 1, wherein:

each given thyristor device includes an undoped spacer layer disposed between said first-type modulation doped quantum well interface and said second-type modulation doped quantum well interface.

13. A radiation detector according to claim 12, wherein:

said first-type modulation doped quantum well interface and said second-type modulation doped quantum well interface are adapted to absorb electromagnetic radiation in a first predetermined wavelength range and said undoped spacer layer is adapted to absorb electromagnetic radiation in a second predetermined wavelength range.

14. A radiation detector according to claim 13, wherein:

said first predetermined wavelength range includes wavelengths between 980 nm and 1650 nm, and said second predetermined wavelength range includes wavelengths between 500 nm and 980 nm.

15. A radiation detector according to claim 13, wherein:

each given thyristor device includes

at least one first-type ion implant in electrical contact with said first-type modulation doped quantum well interface, and

second-type ions implants in electrical contact with said second-type modulation doped quantum well interface.

16. A radiation detector according to claim 15, wherein:

each given thyristor device includes

at least one first channel injector terminal formed from a metal layer deposited on said at least one first-type ion implant, and

at least one second channel injector terminal formed from a metal layer deposited on said second-type ion implants.

17. A radiation detector according to claim 16, wherein:

each given thyristor device includes an anode, an anode terminal electrically coupled to said anode, a cathode, and a cathode terminal electrically coupled to said cathode.

18. A radiation detector according to claim 17, further comprising:

circuitry, electrically coupled to at least one said first and second channel injectors for the given thyristor device in the setup mode, that empties free charge from the corresponding modulation doped quantum well interface.

19. A radiation detector according to claim 17, further comprising:

circuitry, electrically coupled to at least one said first and second channel injectors for the given thyristor device in the signal acquisition mode, that supplies a bias current that adjusts sensitivity of the given thyristor device.

20. A radiation detector according to claim 16, further comprising:

shutter circuitry, electrically coupled to said cathode terminal for the given thyristor device, that selectively operates to couple said cathode terminal to a load element or place said cathode terminal in a high-impedance state.

21. A radiation detector according to claim 20, wherein:

said shutter circuitry couples said cathode terminal for the given thyristor device to the load element during the signal acquisition mode.

22. A radiation detector according to claim 20, wherein:

said shutter circuitry places said cathode terminal for the given thyristor device in a high-impedance state during the setup mode.

23. An apparatus comprising:

the radiation detector of claim 1;

a mask that blocks incident radiation within a spectral range of interest, said mask including multiple apertures positioned above the radiation detector; and

decode logic, operably coupled to the output of the radiation detector, for detecting angle of incidence of an incoming incident radiation based on the output of the radiation detector.

24. An apparatus according to claim 23, further comprising:

a plurality of transmission gates corresponding to the thyristor devices of the radiation detector for selectively transmitting output signals generated by the thyristor devices of the radiation detector.

25. An apparatus according to claim 23, wherein:

the thyristor devices of the radiation detector are arranged as a linear array with a constant active area size over the thyristor devices of the linear array; and

the mask comprises a plurality of two-dimensional apertures whose size vary over rows of such apertures.

26. An apparatus according to claim 23, wherein:

the thyristor devices of the radiation detector are arranged as a two dimensional array with variable active area size over the thyristor devices of the two dimensional array, and

the mask comprises a single slot aperture.

27. An apparatus according to claim 23, wherein:

the thyristor devices of the radiation detector, the mask and the decode logic are arranged to measure angle-of-arrival in two orthogonal directions.

28. An apparatus according to claim 23, wherein:

the mask is integrally formed with the radiation detector.