Sometimes while researching an article or editing an issue, I stumble across a character who so captures my imagination that I can't help but follow the rabbit down its hole.
That is exactly what happened when I read the first draft of Jeff Hecht's Luminary article about Gerald Pearson and his work to create the first silicon solar cell. The story contained a short reference to a paper authored by one Mária Telkes of Massachusetts Institute of Technology (MIT) in 1947—clearly a woman and a scientist, in a decade when the combination was rare. "Who was she?" I wondered.
A few Google searches later, I was excited enough to start gushing to family and strangers about Mária Telkes. We added a second luminary article to this issue just to share her interesting story—one of pluck and perseverance in the face of good ‘ol' boys clubs, xenophobia, and McCarthy-era suspicions of anyone who didn't subscribe to midcentury social norms.
Telkes clashed ideologically with her supervisor at MIT, Hoyt Hottel, who saw solar research as just an interesting engineering problem. In the mid-20th century, petroleum was abundant and cheap; he couldn't envision an economic—or environmental—reason to seriously consider anything else. Telkes, on the other hand, saw solar research as a societal imperative.
Today, the imperative is obvious, and most people working in solar research are in Telkes's camp. Researchers are driven to halt the damage done by humanity's heedless overconsumption of coal and petroleum-an interesting and difficult engineering problem, with a more pressing humanitarian and economic purpose.
The pages of this issue of Photonics Focus should remind us how much scientific progress has been made in a short time. Solar cell efficiency has increased from the six percent that Pearson achieved in 1954 to a useful 25 percent today. Photovoltaic (PV) panels have become affordable and ubiquitous. They are installed in remote communities disconnected from the utility grid to provide electricity where none was previously available.
While today's PV efficiencies are functional, researchers keep finding ways to improve them through new materials, designs, and construction methods. Innovative companies are laminating quantum dots into window glass to create transparent photovoltaics, which will increase the surface area of buildings available to harness sunlight for conversion to usable energy.
Other researchers are looking not to the sun, but to water as a source of renewable energy. If water's hydrogen and oxygen molecules could be quickly and cheaply teased apart, as plants manage so easily through photosynthesis, then the world's most abundant natural resource could be converted to a liquid hydrocarbon, which could replace the energy-dense liquid fuel needed to power jet engines or heat homes.
Luminaries like Telkes and Pearson had the foresight to look beyond the abundance of fossil fuels in their own lifetimes, and the courage to pursue an alternative. Their curiosity and early experiments laid the groundwork for advances in renewable energy. They are the giants upon whose shoulders today's solar researchers stand.
Gwen Weerts, Photonics Focus Editor-In-Chief
