Silicon-based heterojunction double-side solar cell and preparation method thereof

Abstract

The invention discloses a silicon-based heterojunction double-side solar cell and a preparation method of the silicon-based heterojunction double-side cell. The conventional amorphous-silicon thin-film is replaced by the amorphous-silicon germanium alloy as an emitting diode of the heterojunction cell, at the same time, an intrinsic microcrystalline silicon germanium thin-film is used as an interface buffer layer of the cell, so that valence-band offset caused by the heterojunction band mismatch can be reduced effectively, the block influence on the holes is decreased, and the collection of the photovoltaic minority carrier holes is facilitated, furthermore the photovoltaic performance index of the solar cell is increased. The intrinsic microcrystalline silicon germanium thin film, a P-type doped amorphous-silicon germanium thin film, an intrinsic amorphous-silicon thin-film and an N+ type doped amorphous-silicon thin-film are prepared on two sides of the N-type microcrystalline silicon wafer by the radio frequency plasma enhanced chemical vapor deposition, the purpose of effectively collecting a photovoltaic carrier is achieved. The heterojunction double-side solar cell with 14.62% of photoelectric conversion efficiency is prepared on the double-side polished FZ-type microcrystalline silicon wafer by the process.

Description

technical field [0001] The invention relates to a double-sided heterojunction battery in the field of photovoltaic power generation, in particular to an amorphous silicon germanium / microcrystalline silicon germanium / crystalline silicon heterojunction double-sided solar battery and a preparation method thereof. Background technique [0002] Thin-film silicon / crystalline silicon heterojunction solar cell is a photovoltaic solar cell that combines the respective advantages of the first-generation crystalline silicon cell and the second-generation thin-film cell. It mainly relies on crystalline silicon as the absorbing layer, and the thin-film layer is only for A heterogeneous PN junction is formed to collect photogenerated carriers, so the thickness of the film layer is not high, which makes the light stability of this kind of battery high; at the same time, the battery preparation process is mainly the deposition process of the film, and the process temperature is low, about 18...

AI Technical Summary

Problems solved by technology

This kind of battery product, including the designs carried out by many international research institutions, uses amorphous silicon thin film as the emitter of the battery to form a heterogeneous PN junction, collect photo-generated carriers and generate photovoltaic effect, but this design The disadvantage is that the energy band mismatch between the emitter amorphous silicon and the base crystalline silicon is large, and the resulting energy gap barrier hinders the collection of photogenerated minority carriers, which is not conducive to collection, thus affecting Its photovoltaic performance

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