Researchers have integrated solar cells into a ‘smart’ window that can intelligently regulate the transmission of heat while maintaining visible transparency.

The smart window, described in the journal Scientific Reports, combines energy saving and generation in a single device.

Vanadium oxide (VO2) is an attractive material for the fabrication of smart windows because of the reversible, temperature-dependent phase transitions it undergoes. Below a critical temperature of 68 degree Celcius, the material is insulating and transparent to infrared light, but above 68 degree Celcius it becomes metallic and reflective to infrared light.

Previously, it was a challenge to integrate solar cells that can efficiently harness and store solar energy into windows that require the material to be transparent. In this study, Yanfeng Gao and colleagues from the Chinese Academy of Sciences positioned vanadium oxide films around glass panels to regulate solar infrared radiation in response to environmental temperature and scatter partial light to solar cells.

The researchers say that their device may someday contribute towards reducing energy costs for heating, lighting and cooling buildings.

The article can be found at: Zhou J et al. (2013) VO2 thermochromic smart window for energy savings and generation. (Asian Scientist)