As it passes through a solution in a small vial, the green light from a laser pointer in Jennifer Dionne’s hand turns into a sparkling blue beam. By making materials that perform a similar color conversion on sunlight, Dionne hopes to boost the output of solar cells and improve the economics of solar power.
Thirty percent of the sun’s light is wasted in even the best of today’s solar cells because this near-infrared light has too little energy to interact with materials in the cells. Other solar researchers have tried to do what Dionne is doing—”upconversion”—by combining two dyes that interact with each other to convert two low-energy photons into one high-energy photon. But Dionne is taking a new approach that could improve upconversion efficiencies by as much as 50 percent. She added metal nanoparticles to an existing combination of upconversion dyes; the particles shine more light on the dyes and get more converted light out of them.
It’s an early demonstration, but solar-cell maker Bosch is working with Dionne to develop dyes that perform the upconversion. The technology could be incorporated into solar cells in seven to 10 years.—Katherine Bourzac