Light trapping structure based on nano-zinc oxide silicon heterojunction battery, and preparation method of the light trapping structure

Abstract

The invention discloses a light trapping structure based on nano-zinc oxide silicon heterojunction battery. The light trapping structure comprises a silicon substrate which has a pyramid appearance and is prepared by wet etching, a ZnO seed layer, and a zinc oxide nano rod or nano cone growing based on the seed layer, wherein the length of the nano rod or nano cone ranges from 200nm to 1,500nm, and the diameter of the nano rod or nano cone is 20-200nm; the preparation method of the light trapping structure comprises the steps of preparing the pyramid appearance by the wet etching, preparing the seed layer by a solution dipping method, and growing the zinc oxide nano rod or nano cone by a hydrothermal method. The light trapping structure has the advantages that when the light trapping structure is used on a Si substrate solar battery, in a range of 400-1,100nm, the average integral reflectivity of the novel light trapping structure on which the zinc oxide nano rod grows is 5.1%, and the average integral reflectivity of the light trapping structure on which the zinc oxide nano cone grows is only 2.5% in comparison with the average integral reflectivity being 10.9% of the conventional light trapping structure with pyramid appearance, so that the integral reflectivity of the novel light trapping structure is lowered obviously.

Description

technical field [0001] The invention belongs to the preparation technology of silicon-based high-efficiency solar cells, in particular to a light-trapping structure and a preparation method based on nano-zinc oxide-silicon heterojunction cells. Background technique [0002] Solar energy is a clean energy that has the greatest potential to replace fossil energy in the future, and photovoltaic devices must reduce costs and improve conversion efficiency in order to truly become the future energy pillar. In order to reduce costs while maintaining high conversion efficiency, it is a good choice to use amorphous silicon / crystalline silicon heterojunction structure. This kind of cell uses hydrogenated amorphous silicon thin film with wide band gap as the window layer or emitter, single crystal silicon, Using polycrystalline silicon as the substrate, Sanyo first proposed to insert an intrinsic amorphous silicon film between the substrate and the emitter. This heterojunction solar c...

AI Technical Summary

Problems solved by technology

At present, for silicon substrate cells, the method of wet etching is often used to prepare a pyramid structure on the incident surface of light as a light trapping structure, but the theoretical minimum reflectance of the single crystal pyramid structure in the wavelength range of 400-1100nm is 10.49 %, which is far from meeting the light trapping effect needed to improve the efficiency of solar cells

Images