Crystalline silicon cell and its preparation method

Abstract

The invention discloses a crystalline silicon cell piece and a preparation method thereof. The crystalline silicon cell piece comprises a substrate, a gate electrode, a welding electrode, a back electrode and an aluminum back conductive layer, wherein the gate electrode and the welding electrode are arranged on the front of the substrate, and the back electrode and the aluminum back conductive layer are arranged on the back of the substrate; a square resistance value of an area, corresponding to the welding electrode, of the front of the substrate is 20 omega / square - 60 omega / square, the aluminum back conductive layer is 1 micron - 3 microns thicker than that of the back electrode, and the gate electrode is 1 micron - 3 microns thicker than the welding electrode. The preparation method comprises the following steps of (1) diffusing PN junctions; (2) laser doping; (3) film forming; (4) silk-screen printing and (5) sintering. The crystalline silicon cell piece has the advantages of being high in tolerance for welding temperature, not prone to generate electric leakage, and good in packaging performance; the preparation method is low in cost and beneficial to industrial production, and has the advantage of higher cost performance in the field of spaceflight cells for commercial satellites.

Description

technical field [0001] The invention belongs to the field of production and manufacture of solar crystalline silicon cells, and in particular relates to a crystalline silicon cell and a preparation method thereof. Background technique [0002] Solar cell modules for space vehicles not only require high conversion efficiency, but also require high-altitude environmental characteristics such as resistance to atomic oxygen corrosion, low air pressure, and strong vibration. With good environmental adaptability, crystalline silicon cells and gallium arsenide cells have long served space vehicles. With the continuous advancement of multi-junction gallium arsenide battery manufacturing technology, its photoelectric conversion efficiency rapidly exceeds that of crystalline silicon batteries. Since the Shenzhou 7 spacecraft, gallium arsenide batteries have become the first choice for the Shenzhou spacecraft, but the price of gallium arsenide batteries is much higher For crystalline ...

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Problems solved by technology

Electrodes are prepared based on conventional printing silver paste or photolithography. Due to the relatively large square resistance, if resistance welding technology is used, there will be two major problems: 1) The high-temperature sintering temperature of crystalline silicon electrodes is within 880°C, while the peak temperature of resistance welding is generally at Above 900°C, it is very easy for silver to burn through the PN junction, resulting in serious battery leakage; 2) The properties (metal type and content) of the conventional matching silver paste and the silver foil of the soldered interconnection sheet are poorly consistent, and the welding electrode is resistant to high and low temperature cycle changes Poor; 3) The electrode is prepared by evaporation or screen printing, and the height of the electrode in the welding area is the same as that of the finger grid electrode. When the cover sheet and the diluted cover sheet adhesive are packaged, the soldering area is higher than the adjacent finger grid electrode, and packaging bubbles are easily generated due to the height difference, thereby affecting the overall performance of the packaged component

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