Giulia Grancini, Università degli Studi di Pavia
Hybrid Perovskite Solar Cells—A Game Changer for Near-Future Photovoltaics
Written by Elizabeth Wilson
In the past decade, perovskites have emerged as a promising material for solar cells. Current silicon-based solar cell production consumes lots of energy and is technologically intensive.
Perovskite solar cells sound almost too good to be true: with efficiencies of up to 26%, they self assemble from solutions, and production is scalable and less expensive. They're also recyclable and use 90% less energy in manufacturing compared with silicon-based cells. However, they have serious drawbacks that have so far thwarted industrial progress. They are unstable in moisture and heat, they have short lifetimes, and they can possibly release lead as they degrade.
At Wednesday's Symposium X—MRS/The Kavli Foundation Frontiers of Materials, Giulia Grancini, at the Universita degli Studi di Pavia, described her research group’s advances in hybrid perovskite solar cell designs.
A typical three-dimensional design consists of perovskite crystals and organic compounds. Scientists have found that a two-dimensional perovskite structure is more stable in water. But its efficiency is only 15%.
Grancini has been experimenting with hybrid perovskite solar cell designs that combine two-dimensional and three-dimensional perovskite structures, in an attempt to increase both efficiency and stability.
Much attention is now focused on the interface between layers of 2D and 3D materials, where the 2D layer protects the more efficient 3D layer from moisture in a phenomenon known as surface passivation. The industry standard lifetime for solar cells is about 25 years; Grancini's hybrid remained stable over a year of accelerated aging tests, which is more than 25 actual years.
Recently, Grancini's group has been trying to understand how crystal orientation affects charge transport. The 2D perovskites form vertical columns aligned perpendicular to the substrate, which boosts charge transport.
Grancini hopes that new stability breakthroughs will come within a few years, moving the technology towards industrial use.
Symposium X—MRS/The Kavli Foundation Frontiers of Materials features lectures aimed at a broad audience to provide meeting attendees with an overview of leading-edge topics.