One path to cheaper, more powerful solar-power generation involves hitching our fortunes to the photon – a particle of light. But a warning is in order: It’s a strange path that will take us through the counter-intuitive quantum world.
UC Irvine scientists are part of a wave of recent research into the properties of quantum dots. These extremely tiny, semi-conducting crystals could, if properly manipulated, lead to easily fabricated solar panels with a power output significantly greater than conventional panels. Instead of each photon producing a single electron as it moves through an array of quantum dots, it could produce two or more. This would boost the current flowing through the panels, increasing their efficiency – and in turn, driving down the “dollars per watt” ratio to make the more powerful panels less costly to manufacture. To get there, however, researchers must overcome the capricious nature of quantum particles – specifically, their tendency to pop suddenly from one dot to the next in a phenomenon known as quantum tunneling.
UCI researchers are trying to counter this tendency with another somewhat strange quantum effect known as delocalization. The photon literally grows larger, spanning the entire network of quantum dots and causing electrons to travel farther, so they can be harvested, and put to work, before they vanish.