A kind of n-type passivated contact cell and its preparation method

Abstract

The invention discloses a method for preparing an n-type passivated contact cell. After preparing a front emitter, a layer of silicon dioxide is prepared on the front of a silicon wafer as a front passivation layer, a mask layer is polished, and phosphorus-doped polysilicon is removed. The mask layer of the step; use alkaline solution to isolate and polish the edge of the back of the silicon wafer to form a smooth polished surface on the back of the silicon wafer; use the back silicon nitride as the buffer barrier layer of metallization, the back anti-reflection The masking layer in the phosphorous-doped polysilicon step. Further, the present invention also discloses an n-type passivation contact battery prepared by the above method. While ensuring the good performance of the battery, the invention simplifies the preparation process of the n-type passivation contact battery, reduces the preparation cost, and has high feasibility.

Description

technical field [0001] The invention belongs to the technical field of crystalline silicon solar cells, and in particular relates to an n-type passivated contact cell and a preparation method thereof. Background technique [0002] In the field of solar cells, Tunnel Oxide and Passivated Contact (TOPCon) is a new type of high-efficiency solar cell, which passivates crystalline silicon solar cells (hereinafter referred to as cells) by tunneling silicon oxide and doped polysilicon. ) surface to realize the selective passage of photogenerated carriers, that is, the majority carriers can enter the doped polysilicon film through the tunneling silicon oxide layer without hindrance and then be collected, while the minority carriers The recombination rate at the interface of the tunneling silicon oxide and silicon is very low and cannot pass through the tunneling silicon oxide into the doped polysilicon film. TOPCon cells can realize the one-dimensional collection of photogenerated ...

AI Technical Summary

Problems solved by technology

[0003] At present, in the conventional n-type passivation contact battery preparation process, acidic solution is often used to polish the back of the battery to obtain a porous silicon morphology on the back surface of the battery. The roughness is relatively high and not smooth enough, which will reduce the incidence of The reflectivity of long-wavelength light leads to a decrease in the utilization rate of long-wavelength light by the battery; and in the preparation process, nitric acid + hydrofluoric acid system is used for battery back etching and edge isolation, and the harmful gas produced is extremely harmful to the environment. big hazard

On the other hand, the conventional n-type passivated contact cell preparation process mostly uses alumina as the passivation layer of the front emitter, and the preparation equipment of alumina requires high-cost investment; and in the cell preparation process, due to the removal of the surrounding plating The steps of doping polysilicon are complicated, which increases the preparation cost and reduces the production capacity

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