Novel heterojunction bipolar transistor architectures for the practical implementation of high-efficiency three-terminal solar cells

TL;DR

This paper proposes new three-terminal heterojunction bipolar transistor architectures for high-efficiency solar cells, reducing spectral sensitivity and simplifying structure without tunnel junctions, applicable to various material combinations including silicon, III-V, and perovskites.

Contribution

It introduces four novel device architectures for 3T-HBTSCs that enhance efficiency and simplify fabrication compared to existing tandem solar cells.

Findings

Potential efficiency comparable to multijunction cells

Reduced spectral sensitivity compared to traditional tandem cells

Simplified device structure without tunnel junctions

Abstract

Practical device architectures are proposed here for the implementation of three-terminal heterojunction bipolar transistor solar cells (3T-HBTSCs). These photovoltaic devices, which have a potential efficiency similar to that of multijunction cells, exhibit reduced spectral sensitivity compared with monolithically and series-connected tandem solar cells. In addition, the simplified n-p-n (or p-n-p) structure does not require the use of tunnel junctions. In this framework, four architectures are proposed and discussed in this paper: 1) one in which the top cell is based on silicon and the bottom cell is based on a heterojunction between silicon and III-V nanomaterials; 2) one in which the top cell is made of amorphous silicon and the bottom cell is made of an amorphous silicon-silicon heterojunction; 3) one based on the use of III-V semiconductors aimed at space applications; and 4) one in which the top cell is based on a perovskite material and the bottom cell is made of a perovskite-silicon heterostructure.