Ultra-thin solar cell chip with omni-directional reflector and preparation method of ultra-thin solar cell chip

Abstract

The invention discloses an ultra-thin solar cell chip with an omni-directional reflector and a preparation method thereof. The preparation method comprises the following steps: preparing an epitaxialwafer by taking p-type Ge as a substrate, preparing an anti-reflection film ARC and a front electrode on the front surface of the epitaxial wafer, carrying out uniform glue protection on the front surface of the epitaxial wafer, thinning the epitaxial wafer, and evaporating a graphical omni-directional reflector ODR and a back electrode on the back surface of the epitaxial wafer. And the patternsof the omni-directional reflector ODR and the back electrode are complementary, and the area occupied by the back electrode does not exceed 10% of the area of the whole chip. According to the invention, the current of the Ge sub-cell can be improved, the current limiting problem of the Ge sub-cell of the multi-junction cell is solved, the power-to-mass ratio of the solar cell is improved, and thewarping problem of the cell is effectively improved.

Description

technical field [0001] The invention relates to the technical field of solar photovoltaic power generation, in particular to an ultra-thin solar cell chip with a full-angle reflector and a preparation method thereof. Background technique [0002] In recent years, the development of space exploration technology has advanced by leaps and bounds, and space power supply technology has also been continuously developed as an important supporting part. Group III-V multi-junction solar cells have the advantages of high efficiency, long life, and strong radiation resistance, and are widely used in the field of space power sources. At present, the mainstream structure of III-V multi-junction cells is GaInP / GaInAs / Ge triple-junction solar cells composed of GaInP, GaInAs and Ge sub-cells. The conversion efficiency exceeds 41% under 500 times concentrated light, which is much higher than that of crystalline silicon cells. And there is room for further improvement. [0003] The structur...

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Problems solved by technology

[0007] In addition, the metal on the back of the process is completely covered. Due to the difference in the thermal expansion coefficient between the Ge substrate and the epitaxial layer and the metal, the stress between the two causes the chip to bend significantly to the bottom surface, which is not conducive to the stability of the chip.

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