New solar cell breaks 40-percent barrier.

• Author: Herro, Alana
• Position: EYE ON EARTH - Brief article

Scientists have produced a photovoltaic (PV) cell with an energy conversion efficiency of 40.7 percent, the U.S. Department of Energy (DOE) reported in December. The collaboration of DOE and Spectrolab, Inc. (a subsidiary of Boeing) led to the achievement of a decades-old goal: to break the 40-percent efficiency barrier on solar cell devices. "We are eager to see this accomplishment translate into the marketplace as soon as possible," says Alexander Karsner, assistant secretary for energy efficiency and renewable energy at DOE.

The breakthrough cell was developed using a structure called a "multi-junction" solar cell. In this type of device, individual PV cells are made of layers, and each layer captures a portion of the sunlight reaching the cell. This allows the unit to capture energy from a greater range of the solar spectrum, leading to higher efficiency. According to...