Cheap Perovskite Solar Cells Reach 24.5% Efficiency

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 Engineering reported 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.

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

This is really good for flexible, bifacial cells where light comes in from both sides and also for back-contacted cells,” the scientist 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. The new advance, he said, largely removes the last major roadblock to commercial production.