Solar battery having flat contact area and manufacture process thereof

Abstract

The invention discloses a manufacture procedure of a solar battery provided with a flat contacting zone, wherein a cloak screen is arranged on the surface of a solar-power substrate; the partial surface of the cloak screen is defined as the contacting zone, while areas other than the partial surface of the cloak screen is defined as a bare zone; the solar cloak screen on the surface the solar-power substrate is removed after the bare zone is etched and the bare zone on the surface of the solar-power substrate becomes rough; finally, a conduction layer is arranged on the contacting zone of the surface of the solar-power substrate. Therefore, the solar-power substrate is provided with a P-type semiconductor layer, an N-type semiconductor layer, and the conduction layer, wherein the N-type semiconductor layer is formed above the P-type semiconductor layer; the bare zone is a rough surface; the contacting zone is a flat surface; the conduction layer is arranged in the contacting zone.

Description

technical field [0001] The invention relates to a solar cell with a flat contact area and its manufacturing process, especially using a screen to improve the contact between the electrodes laid on the solar cell and the solar substrate. Background technique [0002] In the conventional silicon solar cell manufacturing process, before the electrode is made, it must go through processes such as doping, etching, and heat treatment, and chemical etching is used to perform directional etching on the surface of the chip to form a rough microstructure to increase the light in the solar cell. The route of travel, thereby reducing the light reflectance of the surface of the solar cell. However, if the position where the microstructure is generated is where the electrodes are located, it will easily have a bad influence on the performance of the solar cell. [0003] Among them, as shown in FIG. 1, it is a conventional solar cell with a flat contact area and its manufacturing process ...

AI Technical Summary

Problems solved by technology

However, according to the selective directional tissue etching process, it will definitely cause the deterioration of the contact surface with the electrode A2 and the expansion of the tissue defect in the substrate, so that the defect A3 that can be repaired by post-processing can no longer be repaired.

As a result, it will not only increase the surface area of ​​the defect A3, but also increase the probability of recombination centers and carriers being captured and scattered during the transfer process and reduce the photocurrent that can be collected, so that the solar cell Efficiency drops

In addition, if the aforementioned situation is more serious, a deep pit (pit) A4 will be produced in the solar cell substrate A1, and the formation of the pit A4 will cause the electrode A2 to melt through during operation to produce a channel A5, and by this Channel A5 causes a large increase in leakage current, so that the efficiency of solar cells is seriously reduced, and even defective products are produced.

[0004] At present, relevant improvement methods include the use of lithography or laser processing to achieve selective area directional tissue etching or removal of poor electrode contact surfaces, but these methods are not Precise alignment technology, expensive equipment and long process time are required, and it is not compatible with the current mainstream solar cell manufacturing process, so it is only suitable for the manufacture of a small number of solar cells with special specifications

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