PHOTODETECTOR WITH SURFACE PLASMON RESONANCE

• US 20130228887A1
• Filed: 09/12/2012
• Published: 09/05/2013
• Est. Priority Date: 03/01/2012
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Wehner, Justin Gordon Adams, Smith, Edward Peter Gordon
• Granted Patent: US 8,941,203 B2
• Time in Patent Office: Days
• US Class Current: 257/432
• CPC Class Codes: H01L 27/142 Energy conversion devices photovoltaic modules or arrays of single photovoltaic cells comprising bypass diodes integrated or directly associated with the devices H01L31/0443; photovoltaic modules composed of a plurality of thin film solar cells deposited on the same substrate H01L31/046
• CPC Class Codes: H01L 27/1446 in a repetitive configuration
• CPC Class Codes: H01L 31/00 Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof H10K30/00 takes precedence; devices consisting of a plurality of solid state components formed in, or on, a common substrate, other than combinations of radiation-sensitive components with one or more electric light sources, H01L27/00
• CPC Class Codes: H01L 31/02325 the optical elements not being integrated nor being directly associated with the device
• CPC Class Codes: H01L 31/02327 the optical elements being integrated or being directly associated to the device, e.g. back reflectors optical coatings H01L31/0216
• CPC Class Codes: H01L 31/04 adapted as photovoltaic [PV] conversion devices testing thereof during manufacture H01L22/00; testing thereof after manufacture H02S50/10
• CPC Class Codes: H01L 31/09 Devices sensitive to infrared, visible or ultraviolet radiation H01L31/101 takes precedence
• CPC Class Codes: H01L 31/1013 devices sensitive to two or more wavelengths, e.g. multi-spectrum radiation detection devices
• CPC Class Codes: H01L 31/102 characterised by only one potential barrier

Abstract

Methods and structures for providing single-color or multi-color photo-detectors leveraging plasmon resonance for performance benefits. In one example, a radiation detector includes a semiconductor absorber layer having a first electrical conductivity type and an energy bandgap responsive to radiation in a first spectral region, a semiconductor collector layer coupled to the absorber layer and having a second electrical conductivity type, and a plasmonic resonator coupled to the collector layer and having a periodic structure including a plurality of features arranged in a regularly repeating pattern.

Claims

1. A radiation detector comprising:

a semiconductor absorber layer having a first electrical conductivity type and an energy bandgap responsive to radiation in a first spectral region;

a semiconductor collector layer coupled to the absorber layer and having a second electrical conductivity type; and

a plasmonic resonator coupled to the collector layer and having a periodic structure including a plurality of features arranged in a regularly repeating pattern.

2. The radiation detector of claim 1, wherein the periodic structure of the plasmonic resonator is a grating, and the plurality of features includes a plurality of ridges.

3. The radiation detector of claim 2, wherein the plurality of ridges are interconnected to each other.

4. The radiation detector of claim 2, wherein at least one of a dimension of the plurality of ridges and a period of the grating is selected to impart a predetermined wavelength selectivity or polarization selectivity to the plasmonic resonator.

5. The radiation detector of claim 1, wherein the absorber layer is an n-type semiconductor material, and the collector layer is a p-type semiconductor material.

6. The radiation detector of claim 1, wherein the absorber layer is a p-type semiconductor material, and the collector layer is an n-type semiconductor material.

7. The radiation detector of claim 1, wherein the first electrical conductivity type of the absorber layer is one of n-type and p-type, the second electrical conductivity type of the collector layer is the same as the first electrical conductivity type;

and wherein the absorber layer is separated from the collector layer by a barrier.

8. The radiation detector of claim 1, wherein the first spectral region includes a plurality of wavelengths including at least one first wavelength and at least one second wavelength that is longer than the first wavelength;

wherein the absorber layer includes a first region responsive to radiation having the at least one first wavelength and a second region responsive to radiation having the at least one second wavelength; and

wherein the plasmonic resonator is configured to focus the radiation having the at least one first wavelength into the first region of the absorber layer.

9. The radiation detector of claim 8, wherein the first region of the absorber layer has a thickness approximately equal to a depletion width of the radiation detector.

10. The radiation detector of claim 1, wherein the absorber layer is a first absorber layer and the collector layer is a first collector layer, and further comprising:

a second semiconductor absorber layer having the first electrical conductivity type and a second energy bandgap responsive to radiation in a second spectral region; and

a second semiconductor collector layer coupled to the second absorber layer and positioned between the second absorber layer and the first absorber layer, and having a third electrical conductivity type.

11. The radiation detector of claim 10, wherein the first electrical conductivity type is n-type, the second electrical conductivity type is n+-type, and the third electrical conductivity type is p-type.

12. The radiation detector of claim 10, wherein the first spectral region includes a first plurality of wavelengths, and the second spectral region includes the second plurality of wavelengths that are shorter than the first plurality of wavelengths.

13. The radiation detector of claim 12, wherein the second spectral region includes at least a portion of one of the NIR, SWIR and MWIR spectral regions.

14. The radiation detector of claim 10, wherein the first absorber layer has a thickness approximately equal to a depletion width of the radiation detector.

15. The radiation detector of claim 1, further comprising a substrate, the absorber layer being formed on the substrate and positioned between the substrate and the collector layer.

16. A dual-band radiation detector comprising:

a first collector layer having a first electrical conductivity type;

a first absorber layer having a second electrical conductivity type and a first energy bandgap responsive to radiation in a first spectral region including a first plurality of wavelengths;

a second absorber layer having the second electrical conductivity type and a second energy bandgap responsive to radiation in a second spectral region including a second plurality of wavelengths longer than the first plurality of wavelengths, the first collector layer being positioned between the first and second absorber layers;

a third layer coupled to the second absorber layer and having a third electrical conductivity type, the second absorber layer being positioned between the third layer and the first collector layer; and

a plasmonic resonator coupled to third layer and having a grating structure including a plurality of ridges arranged in a regularly repeating pattern, the plasmonic resonator being configured to focus the radiation in the second spectral region to the second absorber layer.

17. The dual-band radiation detector of claim 16, wherein the first collector layer comprises a p-type material, the first and second absorber layers each comprises an n-type material, and the third layer comprises an n+-type material.

18. The dual-band radiation detector of claim 16, wherein the first and second spectral regions are infrared spectral regions.

19. A dual-band radiation detector comprising:

a first absorber layer having a first electrical conductivity type and a first energy bandgap responsive to radiation in a first spectral region including a first plurality of wavelengths;

a second absorber layer having the first electrical conductivity type and a second energy bandgap responsive to radiation in a second spectral region including a second plurality of wavelengths longer than the first plurality of wavelengths;

a barrier layer disposed between the first absorber layer and the second absorber layer; and

a plasmonic resonator coupled to second absorber layer and having a grating structure including a plurality of ridges arranged in a regularly repeating pattern, the plasmonic resonator being configured to focus the radiation in the second spectral region to the second absorber layer.