Floating junction solar cell back passivation structure based on heterojunction and preparation technology thereof

Abstract

The invention relates to a floating junction solar cell back passivation structure based on heterojunction. The structure comprises P-type crystalline silicon. A bottom of a P-type crystalline silicon substrate possesses a heterogeneous structure which is formed by an intrinsic heterogeneous material layer and an N-type heterogeneous material layer. The intrinsic heterogeneous material layer is inserted between the N-type heterogeneous material layer and the P-type crystalline silicon. An insulating layer wraps the N-type heterogeneous material layer. The bottom of the insulating layer is provided with an aluminum metal layer. Two ends of the bottom of the P-type crystalline silicon substrate are provided with P+ localized doping areas. Point contact aluminum sintering areas are arranged below the P+ localized doping areas. According to the invention, a good passivation effect of the heterojunction can be reserved and simultaneously a photo-generated hole can be well led out through a back structure. And a pin-hole parasitic loop problem of the homogenesis floating junction can be prevented.

Description

technical field [0001] The invention relates to a back passivation technology of high-efficiency solar cells and a process of high-efficiency solar cells, in particular to a back passivation structure of a floating junction solar cell based on a heterojunction and a preparation process thereof. Background technique [0002] Solar power generation is currently the most potential green and clean energy, and high-efficiency solar cells are the core of solar power generation. At present, the battery material with the highest industrialization and maturity of solar cells is still crystalline silicon cells, and the rear passivation technology is the most different among the existing high-efficiency crystalline silicon cell technologies. The degree of back passivation of crystalline silicon not only affects the long-wave incident light response and open circuit voltage of solar cells, but also affects the temperature characteristics of solar cells, which has a major impact on the p...

AI Technical Summary

Problems solved by technology

Both the P+P and P-N junctions of this structure are realized by the heterojunction film on the back of the battery. Like the HIT battery, the heterojunction amorphous silicon is used as both the rear passivation layer and the back electrode layer, so there is also a heterojunction The energy band mismatch problem at the position affects the collection efficiency of photogenerated holes

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