Solar battery

Abstract

The invention discloses a solar battery. The solar battery comprises a substrate layer with the first doping type, at least one front contact member and at least one back contact member, wherein the substrate layer and the front layer opposite to the substrate layer in polarity and having the second doping layer form an interface, a first passivation layer and a tunnel contact layer are arranged between the substrate layer and the back contact member, an intrinsic layer made of a-Si is arranged between the passivation layer and the substrate layer, the passivation layer is made of doped material which has the same polarity with that of the substrate layer, a second passivation layer is formed on the part of the back of the substrate layer not covered by the back contact member and the back contact member, and the refractive index of the second passivation film is higher than 2.6. Through using the substrate material, a solar battery panel can be avoided from bending, arching and rupturing.

Description

technical field [0001] The invention relates to a solar cell, in particular to a solar cell with improved back contacts and the back, which can achieve higher efficiency. Background technique [0002] In a conventional solar cell, the following structure is usually adopted: a pn junction is formed near the light-receiving surface by diffusing impurities whose conductivity type is opposite to that of the substrate relative to the light-receiving surface, and at the same time, a pn junction is arranged on the light-receiving surface electrode, and another electrode is formed on the surface opposite to the light-receiving surface. In addition, generally, impurities of the same conductivity type as that of the substrate can be diffused at a high concentration on the surface opposite to the light-receiving surface to achieve an internal electric field effect, thereby expecting high output efficiency. [0003] On the other hand, in the solar cell having the above-mentioned struct...

AI Technical Summary

Problems solved by technology

[0008] In addition, when the thin silicon wafer is cooling, the back contacts covering the entire surface are subject to strong mechanical stresses, which can lead to fractures and adversely affect processability

[0009] In addition, the cost of the screen printing process is relatively high, and its minimum temperature requirement is about 400°C

However, such a high temperature poses a problem when using thin wafers as the material, that is, the wafers tend to break during processing, and thus lead to a great reduction in yield

Special screen printing pastes are a major cost component in solar cell production and reproducible control of their composition and contact configuration is also costly

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