Semiconductor p-n junction solar cell and method of manufacture
First Claim
1. A solar cell formed of semiconductor material, said cell including an active region where carriers are generated by solar energy which impinges onto and penetrates the cell, means of forming a collecting junction in said cell cooperating with said active region to collect carriers generated in the active region of the cell, said cell including a portion which has a graded impurity concentration which extends over a substantial portion of said active region to form a built-in electric field whereby carriers generated in the graded portion of said active region are transported to said collecting junction primarily by drift in the electric field.
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Accused Products
Abstract
There is described efficient semiconductor p-n junction solar cells which can be made from defect-rich semiconductor material. The solar cells include an extended electric field surrounding the p-n junction for extracting the photo-generated carriers in the presence of defects which would otherwise reduce the efficiency of the cell. There is also described a method of fabricating efficient semiconductor p-n junction solar cells.
143 Citations
14 Claims
- 1. A solar cell formed of semiconductor material, said cell including an active region where carriers are generated by solar energy which impinges onto and penetrates the cell, means of forming a collecting junction in said cell cooperating with said active region to collect carriers generated in the active region of the cell, said cell including a portion which has a graded impurity concentration which extends over a substantial portion of said active region to form a built-in electric field whereby carriers generated in the graded portion of said active region are transported to said collecting junction primarily by drift in the electric field.
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7. The method of improving the efficiency of a solar cell of the type which includes a collection junction cooperating with an active region which comprises the step of grading the impurity concentration in the active region of the cell on at least one side of the junction to provide an extended drift field which cooperates with the junction.
- 8. A solar cell formed of semiconductive material, said cell including an active region where carriers are generated by solar energy impinging and penetrating into said cell, means forming a collecting junction in said active region, and means forming at least one extended drift field in the active region of said cell cooperating with said collecting junction whereby carriers generated in said active region are transported to said junction primarily by drift.
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14. A semiconductor solar cell including a body of semiconductor material supporting an active region, means forming a collecting junction cooperating with said active region, and means in said active region forming an extended drift field in said active region which cooperates with said junction to cause carriers generated in said active region to drift to said collecting junction.
Specification