Electrical engineering

Nanotechnology

Energy conversion efficiency

Crystalline silicon

Heterojunction

Crystallography

Engineering

Perovskite (structure)

Homojunction

Chemistry

Materials science

Layer (electronics)

Photovoltaic system

Solar cell

Polymer solar cell

Passivation

Optoelectronics

Hybrid solar cell

Quantum dot solar cell

Japanese Journal of Applied Physics

High-efficiency back-contact heterojunction crystalline Si (c-Si) solar cells with record-breaking conversion efficiencies of 26.7% for cells and 24.5% for modules are reported. The importance of thin-film Si solar cell technology for heterojunction c-Si solar cells with amorphous Si passivation layers in improving conversion efficiency and reducing production cost is demonstrated. Our attempts to reduce the production cost of a heterojunction c-Si solar cell by applying a SiOx layer prepared by a plasma-enhanced CVD method are presented. The characteristics of heterojunction c-Si solar cells are clarified by comparing them with those of practical homojunction solar cells, and crucial targets for industrialization of back-contact heterojunction c-Si solar cells are discussed. Owing to the recent improvement of c-Si solar cells and perovskite solar cells, conversion efficiencies over 30% have become a realistic target by using a two-terminal tandem structure with a heterojunction c-Si solar cell and a perovskite solar cell.

High-efficiency heterojunction crystalline Si solar cells