A multi-junction compound photovoltaic cell

Abstract

The present invention relates to a multi-subcell compound photovoltaic cell, and in particular, to an InAlAsP / InGaAs / Ge three-subcell compound photovoltaic cell. The present three-subcell compound photovoltaic cell has continuous two-step projection structures each including a first-step projection with a slope and a second-step projection with a slope. A transparent material m2 with a high index of refraction is formed in the regions between the second-step projections, and the top surface of the transparent material m2 is flat and level with the top surfaces of the second-step projections. A transparent material m1 with a high index of refraction is formed in the regions between the first-step projections, and the top surface of the transparent material m1 is level with the top surfaces of the f first-step projections and contacts the transparent material m2 with a high index of refraction. The refractive index of the material m1 is greater than that of the material m2, and light irradiating the top surface of the cell tends irradiate the flat surface of the two-step projection structures, so that the light intensity irradiating the flat surface having a high-quality epitaxial layer is greatly increased, and therefore the photoelectricity conversion rate is increased.

Description

technical field [0001] The invention relates to a compound photovoltaic cell, especially a multi-subjunction compound photovoltaic cell. Background technique [0002] III-V compound photovoltaic cells were first used in the space field, but with the advancement of technology, III-V compound photovoltaic cells are also increasingly used in non-space fields. Compared with silicon photovoltaic cells, III-V compound photovoltaic cells have greater energy conversion efficiency. The photoelectric conversion efficiency of III-V compound photovoltaic cells manufactured through advanced technology can exceed 25%, while silicon photovoltaic cells do not It will exceed 20%. Compared with silicon photovoltaic cells, III-V compound photovoltaic cells can achieve maximum conversion of multiple solar radiations by using multiple sub-cells with different band gap energies. [0003] For III-V compound photovoltaic cells, GaInP / GaAs / Ge is the most typical and mature III-V compound photovolt...

AI Technical Summary

Problems solved by technology

[0003] For III-V compound photovoltaic cells, GaInP / GaAs / Ge is the most typical and mature III-V compound photovoltaic cell, and its photocurrent density can reach 25mA / cm2. However, the existing III-V The spectral absorption of natural sunlight by the group compound photovoltaic cells is not sufficient, and most of them are epitaxial to the semiconductor substrate layer by layer in the form of vertical and multi-junctions, and often cannot form confinement effects on light like silicon photovoltaic cells. Flocking surface, the existing III-V compound photovoltaic cells need to be further improved

Images