Heterojunction solar cell and preparation method thereof

Abstract

The invention relates to a heterojunction solar cell and a preparation method thereof, and belongs to the technical field of solar cell manufacturing. Comprising a crystalline silicon substrate, and a front intrinsic amorphous silicon layer, an N-type doped layer, a front TCO layer and a front metal electrode are sequentially deposited on the front surface of the crystalline silicon substrate; a back intrinsic amorphous silicon layer, a P-type doped layer, a back TCO layer and a back metal electrode are sequentially deposited on the back of the crystalline silicon substrate, and a functional film containing a down-conversion fluorescent material covers a fine gate electrode in the front metal electrode and the front TCO layer which is not shielded by the metal electrode. By introducing the functional film containing the down-conversion fluorescent material, photons in a short-wave region which cannot be utilized by a solar cell can be converted into photon energy matched with spectral response of the photons, namely photons below 400nm are absorbed and converted into low-energy photons of 400-1100nm, so that absorption and utilization of the cell to sunlight are promoted, and the conversion efficiency of the solar cell is improved. The conversion efficiency of the heterojunction solar cell is improved, and the damage effect of part of ultraviolet light on the cell is weakened.

Description

technical field [0001] The invention relates to the technical field of solar cell manufacturing, in particular to a heterojunction solar cell and a preparation method thereof. Background technique [0002] With the increasing demand for energy in the world and the aggravation of carbon emissions, the development of a clean energy system is imminent. As the most potential new energy technology, solar cell technology has been widely studied in recent years. Among them, silicon-based solar cells dominate the application scale and industrial mass production of the photovoltaic industry due to their efficiency advantages. After PERC (back passivation contact cell) battery technology, HJT (silicon-based heterojunction cell), TopCON (tunnel oxide passivation contact), IBC (interdigital back contact cell) are considered to be the most potential at present. three high-efficiency battery technologies. As of March 2022, among all battery technologies that have issued efficiency cert...

AI Technical Summary

Problems solved by technology

The efficiency loss mainly comes from the thermalization loss of photons with energy higher than the bandgap, and the loss that photons with energy lower than the bandgap cannot be absorbed and utilized

Among them, some ultraviolet short-wave photons carry energy higher than the forbidden band width of silicon solar cells, and the excess energy will be lost in the form of heat, which not only causes short-wave photon energy loss, but also generates heat. The output power adversely affects the

This short-wavelength photon loss effect is particularly evident in heterojunction cell structures, because the amorphous silicon film layer in the standard heterojunction cell structure is thicker than the conventional diffusion layer, doped amorphous silicon layer and intrinsic amorphous The thickness of the silicon layer is about 8-15nm, which leads to an increase in the photon absorption rate of the amorphous silicon film layer in the short-wave region, thereby reducing the photons reaching the substrate, further reducing the effective utilization of photons, and affecting the final conversion efficiency of the battery.

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