Multi-Junction Perovskite Solar Cells—Understanding to Drive Device Development

Halide perovskites are exciting optoelectronic materials, with ongoing rapid developments particularly as next-generation photovoltaic technologies. Their greatest promise lies in achieving extremely high efficiency multi-junction solar cells beyond today's leading silicon technologies, whilst maintaining low cost manufacturing -- thus driving down the potential costs of PV.

Here, I will outline our group's recent work on all-perovskite tandem and triple junction solar cells. I will discuss progress in developing these devices in which the perovskite layer is thermally evaporated, leading to greater flexibility in the type and number of layers in the device stack. The precise control over the thickness and quality of the layer leads to exceptional control of current matching in triple junction cells. Using a range of optical and structural mapping techniques, I will show how high the quality of the interfaces can be when using such controlled depositions. Finally, I will also discuss new recombination and interconnect layers, which reduce optical and non-radiative recombination losses in multi-junction cells. These developments will further our understanding of these fascinating semiconductors, whilst also driving forward an important energy technology.