Ion implantation and annealing for thin film crystalline solar cells
AssigneeSolexel, Inc.
InventorsMehrdad M. Moslehi, Virendra V. Rana, Pawan Kapur
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Abstract
A back contact back junction thin-film solar cell is formed on a thin-film semiconductor solar cell. Preferably the thin film semiconductor material comprises crystalline silicon. Base regions, emitter regions, and front surface field regions are formed through ion implantation and annealing processes.
Claims35
A method for making base regions in a thin-film crystalline silicon substrate, the method comprising:
- forming openings in a dielectric layer for base contacts on a thin-film crystalline silicon substrate, wherein said openings form a patterned dielectric layer;
- implanting ions of an dopant element in said thin-film crystalline silicon substrate within said patterned dielectric layer to selectively introduce said dopant element at said base contacts, said patterned dielectric used as an ion implantation mask;
- activating said implanted dopant element to form electrically active doped base contacts;
- forming emitter contacts on said thin-film crystalline silicon substrate;
- and
- forming metallization contacts on said emitter contacts and said base contacts.
A method for making a front surface field region in a thin-film crystalline silicon substrate, the method comprising:
- implanting dopant atoms on the front side of a thin-film crystalline silicon substrate, wherein the dopant element has a peak concentration in the range of 1E16 to 1E20 cm−3;
- and
- activating said implanted ions using laser annealing using a continuous wave (CW) laser or a pulsed laser to form a front surface field on said thin-film crystalline silicon substrate.
A method for making selective emitter regions in a thin-film crystalline substrate, the method comprising:
- forming first openings in a parallel linear region pattern for emitter contacts on a thin-film crystalline silicon substrate;
- selectively implanting ions of an dopant element in said thin-film crystalline silicon substrate at said emitter contacts;
- activating said implanted ions to form doped emitter contacts;
- and
- forming metallization contacts on said emitter contacts and base contacts on said thin-film crystalline silicon substrate.
Dependencies are inferred from the claim text.