Photovoltaic devices
AssigneeFirst Solar, Inc.
InventorsAnil Raj Duggal, Joseph John Shiang, William Hullinger Huber, Adam Fraser Halverson
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Abstract
A photovoltaic device is presented. The photovoltaic device includes a layer stack; and an absorber layer is disposed on the layer stack. The absorber layer includes cadmium, tellurium, and selenium. A semiconductor layer is further disposed on the absorber layer, wherein a valence band offset between the semiconductor layer and the absorber layer is less than about 1.3 electron Volts, and a band gap of the semiconductor layer is in a range from about 1.2 electron Volts to about 3.5 electron Volts.
Claims24
A photovoltaic device, comprising:
- a layer stack, wherein the layer stack comprises a plurality of transparent layers;
- an absorber layer comprising cadmium, tellurium, and selenium disposed on the layer stack;
- and
- a semiconductor layer disposed on the absorber layer, wherein a valence band offset between the semiconductor layer and the absorber layer is less than about 1.3 electron Volts, and a band gap of the semiconductor layer is in a range from about 1.2 electron Volts to about 3.5 electron Volts;
- wherein the absorber layer is between the layer stack and the semiconductor layer;
- wherein the semiconductor layer has an offset in conduction band energy level relative to that of the absorber layer;
- and
- wherein the semiconductor layer comprises CdxM1-xTe, wherein x is a number in a range from 0 to 1, Cd is cadmium, Te is tellurium, and M comprises a divalent metal.
A photovoltaic device, comprising:
- a layer stack, wherein the layer stack comprises a plurality of transparent layers;
- an absorber layer comprising CdSezTe1-z disposed on the layer stack, wherein “z” is a number in a range from about 0 to about 1;
- and
- a semiconductor layer disposed directly in contact with the absorber layer, wherein a valence band offset between the absorber layer and the semiconductor layer is less than about 1.3 electron Volts, and a band gap of the semiconductor layer is in a range from about 1.6 electron Volts to about 2.7 electron Volts;
- wherein the absorber layer is between the layer stack and the semiconductor layer;
- and
- wherein the semiconductor layer has an offset in conduction band energy level relative to that of the absorber layer.
A photovoltaic device, comprising:
- a layer stack, wherein the layer stack comprises a plurality of transparent layers;
- an absorber layer comprising selenium disposed on the layer stack, wherein a concentration of selenium varies across a thickness of the absorber layer;
- a semiconductor layer disposed directly in contact with the absorber layer, wherein a valence band offset between the absorber layer and the semiconductor layer is less than about 0.45 electron Volts, and a band gap of the semiconductor layer is in a range from about 1.6 electron Volts to about 2.7 electron Volts;
- and
- an interfacial layer interposed between the absorber layer and the semiconductor layer;
- wherein the absorber layer is between the layer stack and the semiconductor layer.
Dependencies are inferred from the claim text.