Scientists of Stanford University (United States) have discovered a way to make the electrical wiring on top of solar cells nearly invisible to incoming light. The new design, which uses silicon nanopillars to hide the wires, could dramatically boost solar cell efficiency.
A solar cel is basically a semiconductor, which converts sunlight into electricity, sandwiched between metal contacts that carry the electrical current. This widely used design however has a flaw: the shiny metal on top of the cell actually reflects sunlight away from the semiconductor where electricity is produced, reducing the cell’s efficiency.
Stanford University scientists have discovered how to make the reflective upper metal contact nearly invisible and funnel light now directly to the semiconductor below. They created nanosized pillars of silicon that ‘tower’ above a perforated gold film and redirect the sunlight before it hits the metallic surface. Besides gold, the nanopillar architecture also works with contacts made of silver, platinum, nickel and other metals. The type of the metal used doesn’t really matter, as long as it is invisible to incoming light.
After a series of simulations and experiments, the reflection losses could be limited to only 3 percent. The new technique reportedly has the potential to improve the relative efficiency of solar cells by 10 percent.
Source: Stanford Report