Texturing Auxiliary Agent and Texturing Technology for Polycrystalline Silicon Wafer

Abstract

A texturing auxiliary agent for a polycrystalline silicon wafer is prepared from the following components according to the attached volume percentage: 15%-25% of a surfactant solution, 20%-30% of an oxalic acid solution, and 45%-65% of deionized water. A texturing process of the texturing auxiliary agent for the polycrystalline silicon wafer comprises the following steps carried out according to the order: (a) preparing the texturing auxiliary agent; (b), carrying out acid corrosion; (c), carrying out first rinsing with deionized water; (d) washing with an alkali; (e) carrying out second rinsing with deionized water; (f) pickling; (g), carrying out third rinsing with deionized water; and (h) blow-drying. The texturing auxiliary agent has no toxicity and no corrosivity, and is simple in preparation and use process; the texturing auxiliary agent is applied to the texturing process for the polycrystalline silicon wafer, so that the reflectivity of the polycrystalline silicon wafer after texturing is about 4%-5% lower than that of a polycrystalline silicon wafer textured by a conventional texturing process, and the cell efficiency is increased by 0.1%-0.15%.

Description

technical field [0001] The invention relates to optoelectronic technology, in particular to a texturing auxiliary for polycrystalline silicon wafers and a texturing process. Background technique [0002] The surface reflectivity of solar cells is one of the important factors affecting the photoelectric conversion efficiency of solar cells. Textured on the surface of the solar cell can effectively reduce the surface reflectance of the solar cell through texturing, and the incident light is reflected multiple times on the cell surface to prolong the optical path and increase the absorption of infrared photons, and there are more photons in the p-n Photogenerated carriers are generated near the junction, thereby increasing the collection probability of photogenerated carriers; in addition, with the same size substrate, the p-n junction area of ​​the suede battery is larger, which can improve the short-circuit current and the efficiency. [0003] At present, in the industrial p...

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Problems solved by technology

But this patent needs to add a lot of H 2 SO 4 or H 3 PO 4 To achieve the goal of reducing the reflectivity, the cost of texturing is relatively high; moreover, the patented texturing system is an HF-rich system. After texturing, dark lines formed by deep corrosion pits are prone to appear on the surface of silicon wafers, which will affect the photoelectric conversion of solar cells. Efficiency adversely affected

Chinese patent "additive for acidic texturing agent for polycrystalline silicon solar cells" with application number 201010540761.8 and Chinese patent "additive for acidic texturing liquid for polycrystalline silicon wafers and method of use" with application number 201110212876.9 respectively disclose two acidic texturing agents for polycrystalline silicon wafers. Additives for texturing liquid, wherein the additive composition described in the patent with application number 201110112185.1 and the patent with application number 201010540761.8 is H 2 SO 4 、H 3 PO 4 and H 2 O, the application number is 201110212876.9. The auxiliary agent components described in the patent are polyvinylpyrrolidone, triethanolamine and water. What these three patents describe are only to improve the textured surface of polycrystalline silicon wafers and improve the uniformity of corrosion pits. The three patents cannot provide information about the decrease in the reflectivity of the silicon wafer texture after the use of auxiliary agents, let alone the improvement in efficiency after the use of auxiliary agents, so they cannot be used in large-scale production

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