NANOWIRE BOLOMETER PHOTODETECTOR

• US 20110168894A1
• Filed: 03/12/2009
• Published: 07/14/2011
• Est. Priority Date: 10/20/2008
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Osipov, Viatcheslav V., Bratkovski, Alexandre M.
• Granted Patent: US 8,178,842 B2
• Time in Patent Office: Days
• US Class Current: 250/338.4
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0808 Convex mirrors
• CPC Class Codes: G01J 5/0815 Light concentrators, collectors or condensers
• CPC Class Codes: G01J 5/0853 having infrared absorbers other than the usual absorber layers deposited on infrared detectors like bolometers, wherein the heat propagation between the absorber and the detecting element occurs within a solid
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: G02B 19/0019 having reflective surfaces only (e.g. louvre systems, systems with multiple planar reflectors)
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0042 for use with direct solar radiation
• CPC Class Codes: G02B 19/0076 for use with a detector G02B19/009, G02B19/0095 take precedence
• CPC Class Codes: G02B 19/009 for use with infrared radiation

Abstract

A photodetector for the detection of radiated electromagnetic energy includes at least one bolometer nanowire disposed at least partially within a photon trap. The at least one nanowire has at least one blackened surface. The blackened surface is configured to absorb radiated electromagnetic energy ranging from far-infrared light to visible light.

Claims

1. A photodetector comprising at least one bolometer nanowire disposed at least partially within a photon trap, wherein said nanowire comprises a blackened surface configured to absorb from far-infrared to visible light.

2. The photodetector of claim 1, wherein said nanowire comprises at least one of silicon, germanium, and an alloy of silicon and germanium.

3. The photodetector of claim 1, wherein said photon trap comprises an open reflective cavity.

4. The photodetector of claim 3, wherein said open reflective cavity comprises at least one:

a side reflector slanted with respect to said at least one nanowire, a conical reflector, and a reflector having at least one V-groove.

5. The photodetector of claim 3, wherein said photon trap further comprises a reflector disposed above said cavity and configured to reflect light into said cavity.

6. The photodetector of claim 3, wherein said at least one nanowire is horizontally suspended over said reflective cavity.

7. The photodetector of claim 1, wherein said at least one nanowire is electrically coupled to a first electrode disposed at a first end of said at least one nanowire and a second electrode disposed at a second end of said at least one nanowire.

8. The photodetector of claim 1, wherein said blackened surface comprises at least one of a layer of carbon black and a polymer with embedded light absorbing species configured to absorb from far-infrared to visible light.

9. A photodetector, comprising:

first and second electrodes disposed on opposite sides of a reflective cavity;

a plurality of nanowires disposed at least partially within said reflective cavity, wherein each said nanowire comprises a first end electrically coupled to said first electrode, a second end electrically coupled to said second electrode, and a blackened surface configured to absorb from far-infrared to visible light;

a voltage source configured to apply a voltage difference between said first and second electrodes; and

a meter configured to monitor at least one electrical characteristic of a current flowing between said first and second electrodes and determine an amount of light absorbed by said nanowires from said at least one electrical characteristic.

10. The photodetector of claim 9, wherein said nanowires comprise at least one of silicon, germanium, and an alloy of silicon and germanium.

11. The photodetector of claim 9, wherein said electrical characteristic is a measured magnitude of said current.

12. The photodetector of claim 9, further comprising a top reflector disposed above said reflective cavity.

13. A method of detecting radiated energy, said method comprising:

receiving said radiated energy into a photon trap comprising at least one nanowire disposed at least partially within said photon trap, said nanowire having a blackened surface configured to absorb from far-infrared to visible light;

measuring a resistance of said at least one nanowire, and

determining an amount of light absorbed by said at least one nanowire from said measured resistance.

14. The method of claim 13, wherein said photon trap comprises a reflective cavity.

15. The method of claim 13, wherein said photon trap further comprises a top reflector disposed above said reflective cavity and configured to direct radiated electromagnetic energy into said cavity.