Stanford scientists have discovered how 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 cell is basically a semiconductor, which converts sunlight into electricity, sandwiched between metal contacts that carry the electrical current.
But this widely used design has a flaw: The critical but shiny metal on top of the cell reflects sunlight away from the semiconductor where electricity is produced, reducing the cell's efficiency.
Now Stanford scientists have discovered how to hide the reflective upper contact and funnel light directly to the semiconductor below. Their findings, published in the journal ACS Nano, could lead to a new paradigm in the design and fabrication of solar cells.