Novel N-type silicon hetero-junction battery with IBC (interdigitated back-contacted) structure and fabrication method thereof

Abstract

The invention discloses a novel N-type silicon hetero-junction battery with an IBC structure, wherein an Al2O3 thin film covers the front surface of an N-type silicon substrate; a Si3N4 thin film covers the Al2O3 thin film; intrinsic amorphous silicon and P-type amorphous silicon are deposited on the back surface of the N-type silicon substrate and are provided with a trench respectively; an N-type heavily doped region is arranged at the bottom of each trench; a negative electrode is arranged in each trench; and a positive electrode of the battery is arranged on the back surface of the P-type amorphous silicon. The invention also discloses a fabrication method of the battery. In the invention, since the amorphous silicon is deposited by laser doping and PECVD (plasma enhanced chemical vapor deposition), a high-temperature diffusion process does not occur in the entire process, thereby maximally keeping the service life of minority carriers of the silicon substrate and reducing the damage of the high-temperature process to the N-type silicon substrate. Meanwhile, the battery with the IBC structure enables a battery plate to fully utilize the solar spectra so as to maximally improve the short-circuit current density of the battery; and the stability of the solar battery is improved due to no P-type heavily doped region exists.

Description

technical field [0001] The invention relates to the field of manufacturing crystalline silicon solar cells, in particular to a novel IBC (Interdigitated back-contacted) structure N-type silicon heterojunction cell and a preparation method. Background technique [0002] In the context of energy shortage and increasingly prominent environmental pollution problems, the development of renewable energy has become a major global issue, and the use of solar energy is a key direction for the development of renewable energy. The world photovoltaic market has maintained an average annual growth rate of 30% in the past ten years. The high-speed growth rate of more than 100% has reached an astonishing 152.8% in 2009. Production increased from 7.91GW in 2008 to nearly 20GW in 2009. Compared with foreign advanced cell preparation technology, my country's crystalline silicon solar cell preparation technology is still relatively backward. The basic process consists of texturing, diffusion,...

AI Technical Summary

Problems solved by technology

However, the phosphorus atoms on the front surface of this N-type crystalline silicon cell can still form boron-oxygen bonds with the oxygen in the substrate under the action of ultraviolet light. Conducive to the improvement of solar cell efficiency

At the same time, the shielding of the gate and the high temperature boron diffusion process of about 900 degrees in this traditional battery reduce the minority carrier lifetime of the N-type silicon substrate, which limits the further improvement of the battery efficiency.

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