Preparation method of PERC battery as well as double-faced selective emitter PERC battery

Abstract

The invention discloses a preparation method of a double-faced selective emitter PERC battery. The preparation method comprises the steps of doping the front of a textured P type silicon wafer and then completing deposition of a back passivation layer, a back antireflection layer, a front passivation layer and a front antireflection layer; the preparation method is characterized by also comprisingthe following steps: printing boron-silicon-doped slurry on the back passivation layer of the silicon wafer and drying, and then driving boron into a silicon substrate of the silicon wafer by adopting lasers in a region where the slurry is printed, thus a P+ emitter is formed; meanwhile, forming a linear open window, eliminating redundant boron-silicon-doped slurry by adopting a cleaning fluid and then performing secondary drying, printing front and back electrode slurry on the silicon wafer, and performing high temperature sintering, thus forming an electrode. The preparation method disclosed by the invention adds a drying step after boron slurry is printed, so that laser alignment accuracy is further improved, and product quality is improved; and a step of cleaning and removing the redundant boron-silicon-doped slurry after use of the lasers, so that local ohmic contact quality is improved.

Description

technical field [0001] The invention relates to the technical field of solar cell manufacturing, in particular to a preparation method of a double-sided selective emitter PERC battery and a double-sided selective emitter PERC battery prepared by the preparation method. Background technique [0002] Solar photovoltaic power generation, due to its clean, safe, convenient and high-efficiency characteristics, has become an emerging industry that is widely concerned and focused on development all over the world. [0003] As the thickness of the silicon wafer becomes lower and lower, the cost will be lower and lower, and at the same time, it will bring some negative effects. On the one hand, it will make it easier for minority carriers to diffuse to the surface of the silicon wafer to form recombination. On the other hand, it will cause some long-wave diffraction and transmission. Over the silicon wafer, resulting in a decrease in the conversion efficiency of the battery. Therefo...

AI Technical Summary

Problems solved by technology

The local boron doping process on the back is more difficult to control. The traditional technology generally achieves local back doping by opening a window on the passivation layer and printing boron paste, and then propelling it through high-temperature diffusion. Such a process is not only cumbersome, but also repeatedly The high temperature will also cause more lattice damage. In addition, due to the poor precision, the backside overprint of the double-sided battery cannot be well realized.

In view of the above shortcomings, those skilled in the art have studied the use of laser doping on the back of the silicon wafer, but the products obtained by the existing preparation process are not good, the yield is low, and mass production cannot be realized, so there is currently no way to realize the back of the silicon wafer. Selective Emitter PERC Cell Products with Local Doping

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