Nonpolar solar cell utilizing spontaneous polarization electric field

Abstract

The invention provides a nonpolar solar cell utilizing a spontaneous polarization electric field. The nonpolar solar cell sequentially comprises a substrate, a GaN nucleating layer, a non-doped GaN buffer layer, an n-type GaN layer, an InGaN absorption layer and a p-type GaN layer from bottom to top, wherein all nitride epitaxial layers except the substrate are made of a nonpolar material, a p-type ohmic electrode is led out on the p-type GaN layer, and an n-type ohmic electrode is led out on the n-type GaN layer. As the single-direction spontaneous polarization electric field parallel with the epitaxial layer exists in the nonpolar epitaxial layer, and the p-type ohmic electrode and the n-type ohmic electrode are respectively located at the positive end and the negative end of the spontaneous polarization electric field, the existence of the spontaneous polarization electric field is favorable for improving the horizontal (namely the direction parallel with the surface of the cell) spatial isolation efficiency of a photon-generated carrier electron hole pair in the solar cell, the spontaneous polarization electric field further speeds up the transmission of the separated hole and electron to the positive electrode and the negative electrode, so that the production efficiency of an photoelectric current is greatly improved.

Description

technical field [0001] The invention relates to the field of semiconductor optoelectronic devices, in particular to a non-polar solar cell with a spontaneous polarization electric field. Background technique [0002] InGaN materials have great potential in the preparation of high-efficiency solar cells. First, In x Ga 1-x N material is a direct bandgap semiconductor material. By adjusting the In component in the ternary compound InGaN material, its bandgap energy can be continuously changed between 0.7 and 3.4eV, and its absorption spectrum almost perfectly matches the solar spectrum[1] . Secondly, InGaN material also has the advantages of high absorption coefficient, high electron mobility, high hardness, high temperature resistance, and radiation resistance. It is an ideal material for realizing full-spectrum solar cells, and has broad application prospects and great research value [2]. [0003] However, the photoelectric conversion efficiency of the existing GaN-based...

AI Technical Summary

Problems solved by technology

Adopting this structure can fundamentally solve the problem of compensation of the polarization electric field to the built-in electric field of the p-n junction in traditional polar quantum well structure solar cells, and at the same time use this spontaneous polarization electric field to accelerate the separation of holes and electrons. transported to the positive and negative electrodes respectively, thus greatly improving the photoelectric efficiency of solar cells

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