21. It’s Photovoltaic
George Malliaras
George G. Malliaras, Materials Science and Engineering, and research colleagues demonstrated a new type of organic semiconductor device that shows electroluminescence and acts as a photovoltaic cell. The device is the first to use an ionic junction, and the configuration could lead to improved semiconductor performance. The researchers made a diode out of organic semiconductors containing free ions (molecules with an electrical charge). They created the device by laminating two organic layers, one with free positive ions and the other with negative ions. They added thin conducting films on the top and bottom; the top film is transparent to allow light in and out. The junction shows intense light emission. These devices, which could be fabricated in thin, flexible sheets, could create displays on cloth or paper. The research could lead to mass-produced, inexpensive solar cells.