Texture surface making method for polycrystalline silicon solar battery

Abstract

The invention relates to a texture surface making method for a polycrystalline silicon solar battery. A texture surface making aqueous solution comprises the following components in percentage by weight: 5-20% of hydrofluoric acid, 25-55% of nitric acid, 0.5-5% of silicofluoric acid, 0.1-0.5% of acetic acid, 0.5-1.5% of an additive and the balance of water, wherein the additive comprises the following components in percentage by weight: 0.2-0.8% of polyvinyl alcohol, 0.1-0.6% of triethanolamine, 1-6% of hydrolytic polymaleic anhydride, 0.05-0.1% of polyvinyl pyrrolidone and the balance of water, and the temperature of the texture surface making aqueous solution is 0-30 DEG C. The method comprises the following steps: putting silicon chips into the aqueous solution for 100-300s, performing ultrasonic vibration at the same time at an ultrasonic frequency of 40-60KHZ; and taking out the silicon chips, cleaning the silicon chips in a cleaning solution containing 0.2-0.5% of sodium hydroxide and 0.5-2% of sodium dodecyl benzene sulfonate, taking out the silicon chip and blow-drying. The method has the advantages of good stability, easily controllable temperature, good light-trapping effect on the surface of polycrystalline silicon, high photoelectric conversion rate of the battery, uniform texture surface and low reflectivity.

Description

technical field [0001] The invention relates to the technical field of solar cell preparation methods, in particular to a texturing method for polycrystalline silicon solar cells. Background technique [0002] Polycrystalline silicon is when molten elemental silicon is solidified under supercooled conditions, silicon atoms are arranged in the form of diamond lattices to form many crystal nuclei, and if these crystal nuclei grow into crystal grains with different crystal plane orientations, these crystal grains combine to form crystallization into polysilicon. Polycrystalline silicon cannot be etched with alkali like monocrystalline silicon due to the different crystal orientations of each grain; in order to obtain a good polycrystalline silicon texture, there are currently many methods, such as reactive ion etching, mechanical grooving and chemical etching. . Among them, the chemical corrosion method has been widely used in industrial production due to its convenient opera...

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Problems solved by technology

Although this method does not require specific reaction equipment, the process is relatively simple, and the manufacturing cost is low, but because this method is a pure chemical reaction, the reaction speed of the acid on the silicon wafer is fast, the stability is not easy to control, and the temperature of the reaction also affects the silicon wafer. The key factor of the texturing effect, if the control is not good, the light trapping effect on the polysilicon surface and the photoelectric conversion rate of the battery will be low, the texture of the battery will be uneven, and the reflectivity will be high.

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