Integrated Project M55

Despite the advancements of recent years, solar cells still leave a little bit to be desired in situations where weight must be minimized. 2D semiconductor materials have been considered as a possible solution, but they’ve historically been hampered by inefficiency.

Now, solar cells made with 2D semiconductor materials could reach double the efficiency of previous such devices by optimizing the materials and design, researchers show. Their proposed design gives today’s thin-film solar cells a run for their money, boasting some of the highest power per weight of any thin-film technology available today, at almost 200 watts

The ultralight, flexible solar cells could find use in space-based solar arrays, spacecraft, satellites, drones, wearables electronics, and “powering anything where weight is an issue,” says Deep Jariwala, an electrical and systems engineer at the University of Pennsylvania.

Jariwala and colleagues are researching solar cells made of the 2D semiconductors called transition metal dichalcogenides (TMDs), which include materials such as tungsten selenide and molybdenum disulfide. Researchers have investigated TMDs for over a decade as components for thin-film electronics and sensors. And in the past five years, there has been an increasing interest in their photovoltaic properties. While the first few TMD solar cells had efficiencies under 1 percent, Jariwala’s team reported devices with over 5 percent efficiency last year.