MWT heterojunction silicon solar cell suitable for mass production and preparation method thereof

Abstract

The invention discloses an MWT heterojunction silicon solar cell suitable for mass production and a preparation method thereof. The cell comprises an N-type silicon substrate, and an intrinsic amorphous silicon passivation layer or a silicon oxide passivation layer on the front surface of the N-type silicon substrate is provided with an N-type amorphous silicon film layer. An intrinsic amorphous silicon passivation layer or a silicon oxide passivation layer on the back surface of the N-type silicon substrate is provided with a P-type amorphous silicon film layer. The front surface of the cellis provided with a front metal electrode, and the back surface is provided with a back metal electrode and a hole metal electrode. The outer periphery of each hole metal electrode point is etched witha continuously closed insulating scribe line, and the insulating scribe line penetrates a TCO transparent conductive film and the P-type amorphous silicon film layer on the back surface of the cell.In the method, the emitter of the P-type amorphous silicon film is placed on the back surface of the cell, so that there is no leakage problem in an N-type base region of the hole metal electrode andthe sidewalls, and the method of laser etching of the insulating scribe line around the back hole metal electrode points is used for isolating the P-type amorphous silicon film and the above TCO transparent conductive film, and prevents the short circuit fault from the back positive electrode region.

Description

technical field [0001] The invention relates to a MWT heterojunction silicon solar cell suitable for large-scale mass production and a preparation method thereof, which is applied to the production and manufacture of solar cells. Background technique [0002] Heterojunction silicon cell is a kind of high-efficiency photovoltaic cell, the basic structure is as follows figure 1 As shown, N-type silicon wafers with high minority carrier lifetime are generally used, combined with ultra-thin tunneling passivation layer and P-type amorphous silicon film emitter to obtain a heterogeneous PN junction structure, and the process temperature of the whole process is low (~200°C ), ultra-thin silicon wafers can be used, and the mass production efficiency can reach more than 23%. The disadvantage is that the consumption of silver paste on the front side is high, which not only increases the shading loss but also increases the cost of silver. The MWT (Metal Penetrating Winding) technology...

AI Technical Summary

Problems solved by technology

But a key problem is that MWT technology requires laser opening. For conventional heterojunction cells, the hole cross-sectional structure is complex after opening, and there are P-type (positive electrode) and N-type (negative electrode) regions at the same time. Direct hole metallization It will definitely lead to a short circuit of the positive and negative electrodes, so it is necessary to design and develop a simple, suitable and low-cost MWT heterojunction cell structure and process to make it suitable for large-scale production.

Images