Oct 19, 2017 4:00 pm - Nielsen Hall 170 - Colloquium
Giles Eperon - University of Washington
Halide perovskites - a game-changer for photovoltaics?

The cost of generating electricity from silicon solar panels has continued to drop in recent years, in some locations already being the cheapest way of generating power. The cost of installing solar panels is now limited by non-module costs which cannot easily be reduced, such as frames, transportation, power handling and installation. Thus, the best way to reduce the cost of generating power is to make each module more efficient. However, silicon modules are approaching their practical maximum efficiencies, so to move beyond this will require new technologies.

Perovskite halides have emerged in the last five years as an extremely promising material for solar energy conversion, with efficiencies rising from 4% to over 22% in that time frame. These are low-cost solution-processable semiconductors with bandgap tuneable between 1.2 and 3eV by the choice of specific components of the crystal lattice. A typical perovskite solar cell consists of a thin film of the perovskite material sandwiched between p-type and n-type selective contacts. The range of bandgaps gives the enticing possibility of realizing multi-junction solar cells, and a key benefit is that these would not require lattice-matching as in other technologies.

Here I will introduce the perovskite technology, discuss how it has evolved over the last few years, and explain why perovskites have generated so much interest in the scientific community. I will focus on some of the recent advances we have made, including on understanding the current limitations of the technology and on multi-junction perovskite solar cells. I will discuss how perovskites might fit into the global solar industry, and where I see the future of the technology may lie.