There was an interesting discussion about this exact topic on /r/science [1]. Layperson me's (likely mis-)translation of what they were talking about in that th

There was an interesting discussion about this exact topic on /r/science [1]. Layperson me's (likely mis-)translation of what they were talking about in that thread: the optical bandpass filter might not be a filter in front of all the cells, but the actual cells themselves; or the optical bandpass filter might be on the backs of the cells, reflecting what wavelengths would normally heat up the cells onto a solar thermal collection mechanism. The concentrated PV+solar thermal designs can get pretty intense: the high concentration designs use liquid metal to carry away a 1600°C heat difference. [2] If the UNSW team has hit upon a way to avoid most of that heat from hitting the cells themselves and redirect it straight into the thermal collection system, instead of trying to absorb the heat away from the cells through thermal conduction, then that is a big win. [1] http://www.reddit.com/r/science/comments/2okaxt/researchers_convert_sunlight_to_electricity_with/ http://www.reddit.com/r/science/comments/2okaxt/researchers_... [2] http://www.greenrhinoenergy.com/solar/technologies/pv_concentration.php http://www.greenrhinoenergy.com/solar/technologies/pv_concen...