SEMICONDUCTOR OPTOELECTRONIC DEVICE

• US 20120262701A1
• Filed: 01/07/2011
• Published: 10/18/2012
• Est. Priority Date: 01/08/2010
• Status: Active Grant

• Current Assignee: President and Fellows of Harvard College (Harvard Corporation), U.S. Army Rdecom-Ardec;Attn: Lori Andrews
• Original Assignee: President and Fellows of Harvard College (Harvard Corporation), U.S. Army Rdecom-Ardec;Attn: Lori Andrews
• Inventors: Aziz, Michael J., Said, Aurore J., Recht, Daniel L., Warrender, Jeffrey M.
• Granted Patent: US 8,835,852 B2
• Time in Patent Office: Days
• US Class Current: 356/4.01
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: H01L 31/0288 characterised by the doping material
• CPC Class Codes: H01L 31/068 the potential barriers being only of the PN homojunction type, e.g. bulk silicon PN homojunction solar cells or thin film polycrystalline silicon PN homojunction solar cells
• CPC Class Codes: H01L 31/103 the potential barrier being of the PN homojunction type
• CPC Class Codes: H01L 31/1804 comprising only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 31/1864 Annealing
• CPC Class Codes: H01L 31/1872 Recrystallisation
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A manufacture having an electrical response to incident photons includes a semiconductor substrate; a chalcogen-doped semiconductor active layer on a first side of the substrate; a first contact in electrical contact with the active layer; and a second contact in electrical contact with the substrate; wherein, photons incident upon the active layer cause a variation in current between the first and second contacts.

Claims

1. A manufacture having an electrical response to incident photons, said manufacture comprising:

a semiconductor substrate;

a chalcogen-doped semiconductor active layer on a first side of said substrate;

a first contact in electrical contact with said active layer; and

a second contact in electrical contact with said substrate;

wherein, photons incident upon said active layer cause a variation in current between said first and second contacts.

2. The manufacture of claim 1, wherein said active layer is a single-crystal semiconductor.

3. The manufacture of claim 1, wherein said active layer has a thickness between 50 nm and 500 nm.

4. The manufacture of claim 1, wherein said active layer is silicon.

5. The manufacture of claim 1, wherein said photons incident upon said active layer include infrared photons.

6. The manufacture of claim 1, wherein said photons incident upon said active layer have wavelengths above 1050 nm.

7. The manufacture of claim 1, wherein said active layer is doped with sulfur.

8. The manufacture of claim 1, wherein said active layer is doped with selenium.

9. The manufacture of claim 1, wherein said active layer is doped with a combination of sulfur and selenium.

10. The manufacture of claim 1, wherein said active layer is doped with different types of atoms.

11. The manufacture of claim 1, wherein the active layer is doped to have 1 atomic percent of chalcogen atoms.

12. The manufacture of claim 1, where the active layer is doped to have in excess of 1 atomic percent of chalcogen atoms.

13. The manufacture of claim 1, wherein the active layer has a concentration of chalcogen atoms within the range of 10¹⁸ and 5.10²¹ atoms per cubic centimeter.

14. A method for manufacturing a photovoltaic or light detecting device, said method comprising:

exposing a first side of a substrate to a beam of chalcogen ions to form a chalcogen-doped active layer;

illuminating said first side with a series of short pulses of laser light to melt the surface and to allow the surface to re-solidify between pulses; and

forming electrical contacts on said active layer and on said substrate.

15. The method of claim 14, wherein exposing the first side of the substrate comprising exposing the substrate to a dose of between 1.10¹³ and 5.10¹⁶ chalcogen ions per square centimeter.

16. The method of claim 14, wherein exposing the first side of the substrate comprising exposing the substrate to a dose of about 1.10¹⁴ chalcogen ions per square centimeter.

17. The method of claim 14, wherein exposing the first side to a beam of chalcogen ions comprises selecting a dosage of chalcogen ions such that the concentration of chalcogen atoms in the active layer is sufficient to cause electrical activity in response to exposure to infrared photons.

18. The method of claim 14, wherein exposing the first side to a beam of chalcogen ions comprises selecting a dosage of chalcogen ions such that the concentration of chalcogen atoms in the active layer is between about 10¹⁸ and 5.10²¹ chalcogen atoms per cubic centimeter.

19. The method of claim 14, wherein illuminating said first side comprises illuminating said first side with a series of laser pulses, each of which has a duration of between 1 ns and 50 ns.

20. The method of claim 14, further comprising annealing the photovoltaic device.

21. An apparatus for use in optical communication or rangefinding, said apparatus comprising

an infrared laser;

an optical detector for receiving light from said laser, said optical detector including a chalcogen-doped active layer on a substrate; and

a receiver for receiving a signal from said optical detector, said signal being indicative of illumination by said infrared laser.