A perc solar photovoltaic cell that can improve photoelectric conversion efficiency

Abstract

The invention discloses a PERC solar photovoltaic cell capable of improving photoelectric conversion efficiency, which comprises a silicon substrate and a positive electrode and a back electrode respectively directly sintered on the light-facing surface and the back surface of the silicon substrate, and the light-facing surface of the silicon substrate is successively A silicon dioxide layer, a first passivation layer, an anti-reflection layer, a conductive film and a transparent glass are provided, and a second passivation layer and an aluminum back field are arranged in turn on the back of the silicon substrate sheet, and an additional layer is provided between the conductive film and the transparent glass. There is a metal nanoparticle layer; the solar photovoltaic cell of the present invention has a simple structure. On the one hand, it improves the absorption of light by adopting a light-trapping surface texture and plating an anti-reflection layer; Passivation, the back passivation layer can better reduce the recombination rate of the back surface of the silicon wafer, maximize the minority carrier lifetime of the silicon wafer, and optimize the opening ratio of the back passivation layer, thereby greatly improving the photoelectric conversion efficiency of solar cells.

Description

technical field [0001] The invention relates to a solar photovoltaic cell, in particular to a PERC solar photovoltaic cell capable of improving photoelectric conversion efficiency. Background technique [0002] With the increasing tension of global energy, solar energy has been widely valued by countries all over the world with its unique advantages such as no pollution and large market space. Many large companies in the world have invested in the research and development and production of solar cells. Silicon solar cells are an effective Semiconductor electronic devices that absorb solar radiation and convert it into electricity have been widely used in various lighting and power generation systems. Crystalline silicon solar cells are currently the leading product in the market, and their photoelectric conversion efficiency is relatively high. [0003] Crystalline silicon solar cells are the mainstream of solar cell development at present, occupying most of the market share...

AI Technical Summary

Problems solved by technology

[0004] PERC battery is the earliest high-efficiency battery researched by the photovoltaic device laboratory of the University of New South Wales in Australia. The front adopts an inverted pyramid structure and is passivated on both sides. The back electrode penetrates the passivation layer and contacts the substrate through some small holes separated far away. The highest efficiency of the prepared battery can reach 23.2%. Since the back electrode is directly in contact with the substrate through some small holes, passivation cannot be achieved here. In order to reduce the carrier recombination here as much as possible, the designed The hole spacing must be much greater than the thickness of the substrate, but the increase in the hole spacing increases the lateral resistance (because the carriers have to travel long distances laterally to get here), which leads to a decrease in the fill factor of the battery; in addition, in It is very difficult to realize the ohmic contact of the electrode on the lightly doped substrate, which limits the high-efficiency PERC cell substrate material to only select specific silicon materials. In order to further improve the performance of the PERC cell, the laboratory envisages adding Localized doping, that is, doping concentrated boron at the contact hole between the electrode and the substrate, this idea has long been proposed, but the biggest difficulty is the realization of the doping process, because the solid-state source used at that time for boron doping Afterwards, the carrier life will be greatly reduced. Later, during the experiment, it was found that the use of liquid source BBr3 for boron doping has little effect on the carrier life of the silicon wafer, and it can be compared with the process of preparing a passivation layer using TCA. Good matching, so it is necessary to develop PERC solar cells with independent intellectual property rights

Images