Sunlight can be used to generate electricity either through a photovoltaic effect, or by harnessing the heat produced by the light. There are already hybrid systems that combine both, but scientists at Korea's Yonsei University have now developed a type of hybrid setup that they claim works better.
Led by Prof. Eunkyoung Kim, the researchers placed a dye-sensitized solar cell on top of a film made from a transparent conductive polymer known as PEDOT. Beneath that film was another film made of a pyroelectric material, along with a thermoelectric device – pyroelectricity is a material's ability to generate voltage when heated or cooled, while thermoelectricity involves the conversion of temperature differences to electric voltage (and the other way around).
When exposed to sun-like full-spectrum light, the photovoltaic cell absorbed some of the light and used it to generate electricity. The light that wasn't captured by the cell, however, proceeded through to the PEDOT film, causing it to heat up. The pyroelectric film and the thermoelectric device then utilized that heat to produce more electricity.
According to the scientists, their setup produces a voltage over five times higher than other hybrid systems, and it operates at an efficiency more than 20 percent higher than that of a lone solar cell. They say that it could ultimately find use in applications such as self-tinting sunglasses and windows.
The hybrid system is demonstrated in the video below.
Source: American Chemical Society