Three years ago, scientists at the University of Michigan discovered an artificial photosynthesis device made of silicon and gallium nitride (Si/GaN) that harnesses sunlight into carbon-free hydrogen for fuel cells with twice the efficiency and stability of some previous technologies.

Now, scientists at Lawrence Berkeley National Laboratory — in collaboration with the University of Michigan and Lawrence Livermore National Laboratory — have uncovered a surprising, self-improving property in Si/GaN that contributes to the material’s highly efficient and stable performance in converting light and water into carbon-free hydrogen. Their findings, reported in the journal Nature Materials, could help radically accelerate the commercialization of artificial photosynthesis technologies and hydrogen fuel cells.

Berkeley Lab Research Scientist Sean Lubner is studying materials that can help better store renewable energy to power large-scale systems.