Solar cell with morphing type superlattice structure

Abstract

The invention discloses a solar cell which consists of a plurality of stack 'pn' knot structures and a plurality of tunnel-through junction layers, wherein the tunnel-through junction layers are positioned between the stack 'pn' knot structures; moreover, one of the stack 'pin' knot structures comprises at least one p-typed semiconductor layer, one n-typed semiconductor layer, and one gradient superlattice structure positioned between the p-typed and the n-typed semiconductor layers. An energy gap of the gradient superlattice structure is between the energy gap of indium gallium phosphide (InGap) and the energy gap of gallium arsenide (GaAs). Therefore, a wavelength response range can be improved up to 1.0ev to add the wavelength response frequency spectrum; besides, owing to the gradient superlattice structure, a voltage barrier come up against by a current carrier in the area is relatively small and is easy to be stepped over, thus adding efficiency.

Description

technical field [0001] The present invention relates to a solar cell (Solar Cell), and in particular to a solar cell with a graded superlattice structure (Grading Superlattice Structure) with improved efficiency. Background technique [0002] The main materials of currently commercialized solar cells can be roughly divided into two categories: silicon-based solar cells and III-V compound semiconductor-based solar cells. As far as silicon-based solar cells are concerned, the current efficiency is as high as 18-23%, while III-V compound semiconductor-based solar cells have a direct energy gap, high energy conversion efficiency, and strong radiation endurance. The characteristics and quality are superior to the current silicon semiconductors, so many research reports point out that III-V semiconductor materials are the most suitable materials for the development of high-efficiency solar cells. [0003] The structure of III-V semiconductor solar cells is mainly a tandem structu...

AI Technical Summary

Problems solved by technology

However, in fact, the quality of InGaNAs materials often deteriorates rapidly with the increase of N content, resulting in short carrier diffusion distance, slow moving rate, short carrier lifetime, and high concentration of defect impurities.

And because it is still very difficult to obtain high-quality InGaNAs (1.0eV) epitaxial materials, solar cells with this structure have not been practical so far.

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