Perovskite-Si solar cell: a three-terminal heterojunction bipolar transistor architecture

Over the past decade, perovskite materials have attracted great interest for terrestrial photovoltaic (PV) applications thanks to their cheapness and excellent optoelectronic properties such as tunable bandgap, high absorption coefficient, long carrier lifetime and diffusion length. Perovskites have excellent potential for the development of high efficiency and low cost silicon-based tandem solar cells. Several research studies have been performed about perovskite/silicon tandem solar cells obtaining good conversion efficiencies of about 26%. In this work, we propose a perovksite-silicon solar cell based on the three-terminal hetero-junction bipolar transistor (3T-HBJT) architecture that overcomes several constraints of the series connected double junction cell - i.e. current matching and the need of tunnel junctions or recombination layers - exploiting a simpler structure and achieving high efficiency. In order to evaluate its performance potential, we adopt the classical Hovel model extended to deal with the 3T-HBT structure, demonstrating efficiencies up to 28.6% for cells without antireflection coating.