Sajeev John, a physicist, has developed a method to increase solar energy generation

Applications based on the research of University of Toronto physics professor Sajeev John are currently being developed.

Sajeev John, an award-winning Indo-Canadian theoretical physicist, has developed a process that traps and confines sunlight in ultrathin and flexible silicon sheets. Providing far greater efficiency in generating electricity than conventional solar power technology.

Applications based on the research of University of Toronto physics professor Sajeev John are currently being developed.

Prof John, born in Thiruvalla, Kerala, told the Hindustan Times that his design is based on “the invention of photonic crystals. Which are novel materials that can trap and guide light on a microscopic scale. Specific photonic crystal architectures can be very effective at capturing sunlight. And causing it to bounce around in thin material for an extended period.

Traditional silicon cells are not particularly good at absorbing a wide range of sunlight.

For example, while they are good at absorbing shortwave light, they are not good at absorbing red or near-infrared light. In traditional methods, silicon is made very thick, at 300 microns. Three times the thickness of a human hair, to improve sunlight absorption. The issue is that electrons excited by sunlight must travel a long distance to metallic contacts in such thick solar cells. Before that, energy dissipates in heat, and some of the sunlight is not converted to electricity.

John’s photonic crystal design aims to reduce waste by using a much thinner structure that is only 10 microns thick. “When we can do that and absorb most of the sunlight or more than they were getting with thick silicon. It means that the photo-generated charge carriers can reach their contacts before being distracted and de-activated by something else.”

He claims that the photonic crystal architecture enables 50% more efficient cells than those currently in use. Photonic crystals are also known as “light semiconductors” because they control photons in the same way electronic semiconductors contain electrons.

One application of the invention is that thin silicon solar cells can be encapsulated in flexible sheets to generate power on surfaces. Such as walls or even in clothing such as a winter coat that can charge devices such as cellphones.