Group-IV solar cell structure using group-IV or III-V heterostructures

• US 9,985,160 B2
• Filed: 09/14/2012
• Issued: 05/29/2018
• Est. Priority Date: 09/14/2012
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: King, Richard R., Fetzer, Christopher M., Karam, Nasser H.
• Primary Examiner(s): GONZALEZ RAMOS, MAYLA
• Application Number:
  US13/619,625
• Publication Number:
  US 20140076391A1
• Time in Patent Office: 2,083 Days
• Field of Search: 136243-265
• CPC Class Codes: H01L 31/0687 Multiple junction or tandem solar cells
• CPC Class Codes: H01L 31/0725 Multiple junction or tandem solar cells
• CPC Class Codes: H01L 31/074 comprising a heterojunction with an element of Group IV of the Periodic Table, e.g. ITO/Si, GaAs/Si or CdTe/Si solar cells
• CPC Class Codes: H01L 31/0745 comprising a AIVBIV heterojunction, e.g. Si/Ge, SiGe/Si or Si/SiC solar cells
• CPC Class Codes: H01L 31/078 including different types of potential barriers provided for in two or more of groups H01L31/062 - H01L31/075
• CPC Class Codes: Y02E 10/544 Solar cells from Group III-V materials

Abstract

Device structures, apparatuses, and methods are disclosed for photovoltaic cells that may be a single junction or multijunction solar cells, with at least a first layer comprising a group-IV semiconductor in which part of the cell comprises a second layer comprising a III-V semiconductor or group-IV semiconductor having a different composition than the group-IV semiconductor of the first layer, such that a heterostructure is formed between the first and second layers.

Claims

1. A photovoltaic cell comprising:

at least two group-IV subcells within a multijunction cell, wherein at least one upper subcell is positioned closer to a primary light source than at least one lower subcell, wherein the at least one upper subcell has a higher direct or indirect energy bandgap than the lower subcell, and wherein at least one of the group-IV subcells further comprises a first layer comprising a solar cell emitter layer formed from a group-IV layer, and a second layer comprising tunnel junctions formed from one or more group III-V semiconductor layers, the group-IV layer forming a heterojunction with the one or more group III-V semiconductor layers.

2. The photovoltaic cell of claim 1, wherein the compositions for the upper and lower subcells are selected from the group consisting of:

Ge, Si, SiGe, CGe, GeSn, SiGeSn, and CSiGeSn.

3. The photovoltaic cell of claim 1, wherein at least one upper subcell comprises SiGeSn, and at least one lower subcell comprises Ge.

4. The photovoltaic cell of claim 1, wherein the one or more group III-V semiconductor layers are selected from the group consisting of:

GaAs, AlGaAs, GaInAs, AlGaInAs, InP, GaP, GaInP, GaInPAs, AlInP, AlGaInP, InAs, InPAs, AlInAs, AlAs, GaSb, GaAsSb, InSb, GaInAsSb, GaInNAs, GaInNAsSb, GaN, AlN, InN, GaInN, AlGaN, AlInN, AlGaInN, and combinations thereof.

5. The photovoltaic cell of claim 1, wherein the tunnel junctions are selected from the group consisting of:

p+GaAs/n+GaAs tunnel junctions;

p+AlGaAs/n+GaAs tunnel junctions;

p+GaAs/n+AlGaAs tunnel junctions;

p+AlGaAs/n+AlGaAs tunnel junctions;

p+AlGaAs/n+GaInP tunnel junctions;

p+AlGaAs/n+AlGaInP tunnel junctions; and

p+AlGaInP/n+AlGaInP tunnel junctions.

6. The photovoltaic cell of claim 1, wherein the two or more group-IV subcells are subcells within a multijunction photovoltaic cell.

7. The photovoltaic cell of claim 6, wherein the group-IV layer is epitaxially grown on the group III-V semiconductor layers.

8. The photovoltaic cell of claim 1, wherein the group-IV layer is n-type and at least one of the group III-V semiconductor layers is p-type.

9. The photovoltaic cell of claim 7, wherein the group-IV layer is n-type and at least one of the group III-V semiconductor layers is p-type.

10. The photovoltaic cell of claim 1, wherein the at least one of the group-IV subcells further comprises a base layer.

11. The photovoltaic cell of claim 1, wherein the at least one of the group-IV subcells further comprises a base layer, wherein the emitter layer comprises a lower energy bandgap than the base layer of the subcell.

12. The photovoltaic cell of claim 1, wherein the at least one of the group-IV subcells further comprises a base layer, wherein the emitter layer comprises a higher energy bandgap than the base layer of the solar cell.

13. The photovoltaic cell of claim 1, wherein the at least one of the group-IV subcells further comprises a base layer, wherein the emitter layer has approximately the same energy bandgap as the base layer of the solar cell.

14. A vehicle comprising the photovoltaic cell of claim 1.

15. An energy storage system comprising the photovoltaic cell of claim 1.

16. An energy generation system comprising the photovoltaic cell of claim 1.

17. A method for energy generation comprising the step of:

providing a photovoltaic cell comprising at least two group-IV subcells within a multijunction cell, wherein at least one upper subcell is positioned closer to a primary light source than at least one lower subcell, wherein the at least one upper subcell has a higher direct or indirect energy bandgap that the lower subcell, wherein at least one of the group-IV subcells further comprises a first layer comprising a solar cell emitter layer formed from a group-IV layer, and a second layer comprising tunnel junctions formed from one or more group III-V semiconductor layers, the group-IV layer forming a heterojunction with the one or more group III-V semiconductor layers, and wherein the group-IV layer is epitaxially grown on the one or more group III-V semiconductor layers.

18. The method of claim 17, wherein the compositions for the upper and lower subcells are selected from the group consisting of:

Ge, Si, SiGe, CGe, GeSn, SiGeSn, and CSiGeSn.

19. The method of claim 17, wherein at least one upper subcell comprises SiGeSn, and at least one lower subcell comprises Ge.