Hot carrier solar cell

Abstract

A hot-carrier solar cell includes a semiconductor layer, a metal layer, a first electrode, and a second electrode. The upper surface of the semiconductor layer is planar or has an inverted pyramid or microstructure array. The lower surface of the metal layer is in contact with the upper surface of the semiconductor layer. The first electrode is in contact with the upper surface of the metal layer. The period of the inverted pyramid array, as well as the surface morphology, thickness, plating rate, grain size, spacing between metal particles, and annealing temperature of the metal layer, all affect the characteristics of the cell. By adjusting one or more of these parameters, the efficiency of the solar cell for incident light with wavelengths greater than 1100 nm is increased to 6.1%.

Claims

1. A hot carrier solar cell, comprising: a semiconductor layer; a metal layer comprising a plurality of continuous or discontinuous metal nano islands in contact with an upper surface of the semiconductor layer; a first electrode in contact with the upper surface of the metal layer; and a second electrode in contact with a lower surface of the semiconductor layer; wherein carriers in the metal layer, upon excitation by incident photons, form hot carriers that cross the interface between the metal layer and the semiconductor layer to form a photocurrent; wherein the hot carrier solar cell can absorb incident light with a wavelength greater than the wavelength corresponding to the bandgap of the semiconductor layer, thereby achieving a conversion efficiency of 6% or higher for the hot carrier solar cell.

2. The thermal carrier solar cell of claim 1, wherein the metal layer further comprises a plurality of metal particles of a predetermined morphology above the plurality of metal nano islands.

3. The thermal carrier solar cell of claim 1, wherein the upper surface of the semiconductor layer has an inverted pyramid array.

4. The thermal carrier solar cell of claim 1, wherein the upper surface of the semiconductor layer has a one-micron array of structures that confine light therein for resonance.

5. The thermal carrier solar cell of claim 3, wherein the first electrode is a finger or mesh electrode located on a plurality of planes between adjacent inverted pyramid structures of the inverted pyramid array.

6. The thermal carrier solar cell of claim 2, wherein the average particle size of the plurality of metal particles is between 30 nm and 100 nm.

7. The thermal carrier solar cell of claim 2, wherein the spacing between the plurality of metal particles is between 0.2 nm and 5 nm.

8. The thermal carrier solar cell of claim 5, wherein the period of the inverted pyramid array is between 2 μm and 16 μm.

9. The thermal carrier solar cell of claim 2, wherein the thickness of the metal layer is between 8 nm and 18 nm.

10. A thermal carrier solar cell as claimed in claim 1 or 2, wherein the metal layer is formed by thermal evaporation with a deposition rate between 0.6 Å / S and 1.2 Å / S.

11. The thermal carrier solar cell of claim 1 or 2, wherein the material of the metal layer comprises gold, silver, titanium, copper, chromium, or nickel.

12. A thermal carrier solar cell as claimed in any of claims 1 to 4, wherein the absorptivity for incident light at a wavelength of 1300 nm reaches 70.44%.

13. A thermal carrier solar cell of any one of claims 1 to 4, wherein the solar cell is annealed at a temperature between 35°C and 200°C.

14. The thermal carrier solar cell of claim 5, wherein a portion of the finger or mesh electrode is located directly above a portion of the inverted pyramid structure of the inverted pyramid array.

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