Quantum Wells in Photovoltaic Cells

TL;DR

This paper discusses the use of quantum wells in photovoltaic cells to surpass traditional efficiency limits by enabling better spectrum absorption, focusing on quantum well cells as an alternative to multi-junction solar cells.

Contribution

It introduces quantum well cells as a novel approach to improve solar cell efficiency beyond single bandgap limitations.

Findings

Quantum wells can enhance spectral absorption in solar cells.

Quantum well cells offer a potential alternative to multi-junction configurations.

Theoretical analysis suggests efficiency improvements with quantum well integration.

Abstract

The fundamental efficiency limit of a single bandgap solar cell is about 31% at one sun with a bandgap of about Eg = 1.35 eV (1), determined by the trade-off of maximising current with a smaller bandgap and voltage with a larger bandgap. Multiple bandgaps can be introduced to absorb the broad solar spectrum more efficiently. This can be realised in multi- junction cells, for example, where two or more cells are stacked on top of each other either mechanically or monolithically connected by a tunnel junction. An alternative or complementary (see section 1.4) approach is the quantum well cell (QWC).