Potential of the three-terminal heterojunction bipolar transistor solar cell for space applications

TL;DR

This paper explores the potential of three-terminal heterojunction bipolar transistor solar cells for space applications, highlighting their advantages in efficiency and simplified structure over traditional multi-junction solar cells.

Contribution

It introduces a novel three-terminal heterojunction bipolar transistor solar cell architecture with potential benefits for space use, especially in maintaining high efficiency over extended operational periods.

Findings

Potential for higher end-of-life efficiency in space conditions

Simplified structure without tunnel junctions

Advantages over series-connected multi-junction cells

Abstract

Multi-terminal multi-junction solar cells (MJSC) offer higher efficiency potential than series connected (two-terminal) ones. In addition, for terrestrial applications, the efficiency of multi-terminal solar cells is less sensitive to solar spectral variations than the two-terminal series-connected one. In space, generally, cells are always illuminated with AM0 spectrum and no impact is expected from spectral variations. Still, in space, the multi-terminal approach offers some advantages in comparison with the series-connected architecture approach derived from a higher end of life (EOL) efficiency. In this work we review the potential of multi-terminal solar cells for achieving extended EOL efficiencies with emphasis in the potential of the three-terminal heterojunction bipolar transistor solar cell, a novel multi-terminal MJSC architecture with a simplified structure not requiring, for example, tunnel junctions.