Rice University engineers say they've solved a long-standing conundrum in making stable, efficient solar panels out of halide perovskites.
It took finding the right solvent design to apply a 2D top layer of desired composition and thickness without destroying the 3D bottom one (or vice versa). Such a cell would turn more sunlight into electricity than either layer on its own, with better stability.
Chemical and biomolecular engineer Aditya Mohite and his lab at Rice's George R. Brown School of Engineeringreported in Science their success at building thin 3D/2D solar cells that deliver a power conversion efficiency of 24.5%.
That's as efficient as most commercially available solar cells, Mohite said.
"This is really good for flexible, bifacial cells where light comes in from both sides and also for back-contacted cells," he said. "The 2D perovskites absorb blue and visible photons, and the 3D side absorbs near-infrared."
Perovskites are crystals with cubelike lattices known to be efficient light harvesters, but the materials tend to be stressed by light, humidity and heat. Mohite and many others have worked for years to make perovskite solar cells practical.
A discovery by Rice University engineers brings efficient, stable bilayer perovskite solar cells closer to commercialization. The cells are about a micron thick, with 2D and 3D layers. Credit: Jeff Fitlow/Rice University
The manufacture of high-efficiency solar cells with layers of 2D and 3D perovskites by multiple processes may be simplified by solvents that allow solution deposition of one layer without destroying the other, according to new research at Rice University. Credit: Jeff Fitlow/Rice University
Rice University graduate student Siraj Sidhik sets up an experiment to expose a bilayer perovskite cell to artificial sunlight. Cells created in the Rice lab exposed to strong light for 2,000 hours degraded their efficiency by less than 1%. Credit: Jeff Fitlow/Rice University
Andrew Torma, an Applied Physics graduate student at Rice University, validates the electronic structure of a 2D/3D perovskite solar cell. Credit: Jeff Fitlow/Rice University