To this end, the Californian scientists developed a technique capable of “trapping” the photons that make up light in a layer of polymeric materials.
To say the truth, this technique is already used by research labs, being considered a suitable alternative to silicon-made photovoltaic solar cells.
The real innovation introduced by the Stanford team consists in the adoption of the nanometric scale: this means that extremely thin polymeric layers are used, whose width ranges within millionths of a millimetre. By working on this size range, researchers found that photons could be trapped for longer, thus increasing energy absorption far more than what had been achieved with traditional techniques. In short, the way in which the new technique confines the photons in a way allows it to capture a much greater amount of energy from light.
According to the research team, «the advantage thus obtained is really surprising. By exceeding the limits of traditional techniques, it is possible to design far more efficient solar cells».
Cells developed by using of the new technique are expected not only to have an improved efficiency, but also to be less costly, since polymers are far less expensive than silicon and, additionally, only a reduced amount will be needed to manufacture ultra-thin cells.