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US 12,610,650 B2Granted
Doped photovoltaic semiconductor layers and methods of making
AssigneeFirst Solar, Inc.
InventorsSachit Grover, Stuart Irvine, Xiaoping Li, Roger Malik, Shahram Seyedmohammadi, Gang Xiong, Wei Zhang
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Abstract
Provided are structures and methods for doping polycrystalline thin film semiconductor materials in photovoltaic devices. Embodiments include methods for forming and treating a photovoltaic semiconductor absorber layer.
Claims20
A method for forming a doped semiconductor absorber layer, comprising:
- disposing an absorber layer of a photovoltaic stack to form an absorber film comprising cadmium, tellurium, and selenium, wherein disposing the absorber layer comprises depositing in one or more layers:
- a first material and a second material onto a window stack in a first deposition environment, wherein:
- the first material comprises a II-VI semiconductor or precursor, and
- the second material comprises a group V dopant or dopant precursor;
- contacting at least a portion of the absorber film with a third material, wherein the third material comprises a passivating agent;
- heating the photovoltaic stack with a reducing agent in a reducing environment, wherein:
- the reducing agent comprises hydrogen gas (H2);
- the reducing environment comprises at least a trace amount of oxygen (O2);
- the reducing environment comprises H2 in a range from 0.06% to 3.0%;
- and
- a ratio of the partial pressure of H2 to the partial pressure of O2 is equal to or greater than 0.24.
8 more elements
A method for forming a doped semiconductor absorber layer, comprising:
- disposing an absorber layer of a photovoltaic stack to form an absorber film, wherein disposing the absorber layer comprises depositing in one or more layers:
- a first material and a second material onto a window stack in a first deposition environment, wherein:
- the first material comprises a II-VI semiconductor or a II-VI semiconductor material precursor, and
- the second material comprises a group V dopant or a group V dopant precursor;
- applying a first heat treatment to the absorber film in a first heat-treating environment;
- contacting at least a portion of the absorber film with a passivating agent;
- applying a second heat treatment to the absorber film in a second heat-treating environment;
- and
- supplying a reducing gas to the second heat-treating environment to produce a reducing environment;
- wherein:
- the reducing gas comprises hydrogen gas (H2);
- the reducing environment comprises at least a trace amount of oxygen (O2);
- the reducing environment comprises H2 in a range from 0.06% to 3.0%;
- and
- a ratio of the partial pressure of H2 to the partial pressure of O2 is equal to or greater than 0.24.
12 more elements
Dependencies are inferred from the claim text.