| 摘要 |
A monolithic photovoltaic cell (20) that includes at least one upper cell (24) and two or more lower cells (26) is disclosed. The upper cell is separated from the lower cells by an intrinsic isolation layer (28) to which both the upper and lower cells are bonded. A conductive backplane (30) formed integrally with the upper cell serves as a member of that cell and is actually bonded to the intrinsic isolation layer. Each lower cell is provided with a conductive backplane (32) that functions as the interface between the cell and the intrinsic isolation layer. A selectively applied metallization layer (31) series connects the lower tandem cells together and connects the lower cells in parallel across the upper cell. Dielectric material (48) is applied between the individual photovoltaic cells (24, 26) and the metallization layer to prevent the metallization layer from shorting out the photovoltaic cells. In one embodiment of the invention, the upper photovoltaic cell may be an AlGaAs homojunction photovoltaic cell, the lower cells may be CuInSe2/CdZnS heterojunction photovoltaic cells, and a layer of ZnSe may serve as the isolation layer between the cells. In one version of this embodiment of the invention, the n-regions of the upper and lower cells are located closest to the isolation layer. In one method of manufacture, the upper cell structure is initially epitaxially grown on a wafer, the isolation layer is grown over the upper cell structure, the lower cells are formed over the isolation layer, the entire structure is separated from the wafer and inverted, the upper cell is formed from the upper cell structure, and the upper cell is metallized to connect it to the lower cells.
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