A new solar cell configuration developed by Australian engineers at the University of New South Wales in Sydney has pushed sunlight-to-electricity conversion efficiency to 34.5%! This is a new world record for unfocussed sunlight and nudging closer to the theoretical limits for such a device.
Higher conversions have been achieved in the past (over 40%), but this was done by using mirrors to concentrate the light (CPV). This new find is using normal sunlight with no concentrators! This method has sunlight passing through a triple-junction cell using a combination of 3 layers, where each layer, energy is then extracted by each junction at its most efficient wavelength, while the unused part of the light passes through to the next layer, and so on.
We should not get too excited just yet, multi-junction solar cells of this type are unlikely to find their way onto the rooftops of homes and offices anytime soon, as they require more effort to manufacture and therefore cost more than standard crystalline silicon cells with a single junction.l
The full article is here - Solar Daily