sunTune (High-Efficiency Solar Cells by Spectral Transformation Using Nano-Optical Enhancement)


Following up on investigations of the underlying physical mechanisms, the project will use advanced nanotechnology to develop materials for efficiency improvements through the mechanism of photon upconversion. Afterwards, these materials will be merged with state-of-the-art photovoltaic materials in order to develop high-efficiency solar cells for commercial use.

The sunTune project combines researchers from three Danish universities, one international research centre and two Danish companies.


Conventional crystalline silicon solar cells normally suffer a 70% loss in the conversion of the incoming solar energy, among other things because long-wavelength sunlight is not absorbed.

sunTune exploits the long-wavelength light by effectively “tuning” the sunlight spectrum to better match the range of the efficient current generation of the solar cell. In order to achieve this goal, a method for (up-)­converting two low-energy photons into one high-energy photon is being developed. This process will be furthermore optimised by employing advanced nanotechnology on the solar cell in the form of additional active layers. This will lead to an increased current generation – particularly during morning- and evening-light illumination, when long-wavelength light is more abundant.