Heterojunction GaSb infrared photovoltaic cell
AssigneeJX Crystals Inc.
InventorLewis M. Fraas
Life of this patent
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Abstract
Heterojunction GaSb Photocells for operating in wavelengths around 1.6 microns have P type GaSb wafers with backside P+ back metal contacts. Patterned active areas are created on the front side and receive a thin passivation film. A thin N+ transparent SnO2 or tin conductive oxide is deposited on the passivation film. A front contact grid is deposited. The thin passivating film is either amorphous silicon (a-Si:H) or TiO2 with a hydrogen plasma pretreatment. The deposited N+ transparent SnO2 or tin conductive oxide forms an N+/P Heterojunction cell. Front grid contacts and full back contacts are deposited. An antireflective coating is applied through the grids.
Claims16
Apparatus comprising:
- heterojunction N+ on P GaSb infrared photovoltaic cell, further comprising:
- a P type GaSb single crystal substrate having a front side and a back side,
- a P+ ohmic metal contact on the back side,
- a thin passivating front side coating,
- a N+ transparent conductive oxide coating on the thin passivating front side coating, and
- a collecting front metal grid on the transparent conductive oxide coating;
- wherein the heterojunction is between the N+ transparent conductive oxide coating and the P type GaSb single crystal substrate.
A process for forming an infrared photovoltaic cell comprising:
- providing a P type GaSb single crystal wafer as the substrate, having a front side and a back side,
- depositing a SiNx layer on the front side of the wafer,
- diffusing a P+ ohmic metal contact on the back side of the wafer,
- patterning the SiNx layer, and creating cell active areas on the front side,
- depositing a passivation layer on the cell active areas,
- depositing an N+ transparent conductive oxide coating on the passivation layer,
- depositing and patterning an antireflection coating layer, and
- depositing front and back contacts on the front side and the back side, respectively;
- wherein a heterojunction is formed by the N+ transparent conductive oxide coating and the p type GaSb single crystal substrate.
Dependencies are inferred from the claim text.