Optical and electrical modelling for high efficiency perovskite/silicon tandem solar cells

A tandem arrangement of high and low bandgap solar cells is a promising way to achieve high efficiency solar energy conversion at low cost. Four-terminal tandems, in which each cell is connected independently, avoid the need for current matching between the top and bottom cells, giving greater design flexibility. We perform optical and electrical modelling of the efficiency potential for perovskite/silicon tandems, and show that efficiencies of over 30% are realistically possible. We further show that optimizing the transparent conducting layers and applying a grid are important steps to achieving high efficiency. Finally we demonstrate an efficiency of over 20% for a perovskite/silicon tandem in a four-terminal stack, and 23% in a reflective configuration.