A n-type pert double-sided battery structure suitable for thinning and its preparation method

Abstract

The invention discloses an N-type PERT double-sided battery structure suitable for being thinned and preparation method thereof. The structure comprises a silicon substrate. On the front face of the silicon substrate, an n+ lightly doped layer and a local n++heavily doped region are formed. On the n+ lightly doped layer, a passivation antireflection layer is formed through a technology step. A cathode is guided out from the n++heavily doped region. On the back face of the silicon substrate, a p+ doped layer is formed and a second passivation antireflection layer is formed through a technology step. An anode is guided out from the p+ doped layer. When the n+ doped layer is transferred to the front face of a battery, the light blocking size by metal grating wires can be reduced and the contact and composition of electrodes are reduced; in addition, the formed n++ local heavily doped region increases the open circuit voltage and the short circuit current of the battery substantially, and at the same time, enables the square resistance of the n+ doped layer to be raised to a higher level. This is favorable to increase the surface passivation effect. As both the first passivation antireflection layer and the second passivation antireflection layer are prepared through one technology step, the technology manufacturing procedures are optimized greatly, therefore, increasing the production efficiency and reducing the manufacturing cost.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to an N-type PERT double-sided cell structure suitable for thinning (silicon sheet thickness of 170 microns or less) and a preparation method thereof. Background technique [0002] Because of its cleanness, safety, convenience, and high efficiency, solar photovoltaic power generation has become an emerging industry that is widely concerned and focused on development by countries all over the world. Therefore, in-depth research and utilization of solar energy resources is of great significance to alleviate the resource crisis and improve the ecological environment. [0003] The N-type PERT battery is similar to the traditional P-type battery in structure, and is considered to be the most compatible N-type high-efficiency battery with traditional conventional production line processes and equipment, because it has the unique low light induced degradation (LID, Light InducesDegrada...

AI Technical Summary

Problems solved by technology

With the development of silicon wafer thinning, the efficiency of N-type PERT double-sided cells produced by this structure and process will continue to decrease

In addition, since the front electrode uses silver-aluminum paste to form ohmic contact with the p+ layer, the conductivity of the silver-aluminum paste is worse than that of the silver paste, so the width of the front grid line is required to be large (the width of the auxiliary grid line is usually more than 50 microns after sintering), and the silver The aluminum paste will form serious recombination in the contact area with the silicon wafer, which limits the further improvement of battery efficiency and affects the development of N-type PERT double-sided batteries

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