SunTune - High-efficiency solar cells by spectral transformation using nano-optical enhancement

The total annual radiation from the Sun on the surface of the earth is almost 10,000 times more powerful than our annual global power consumption. However, the exploitation of solar energy is still not sufficiently cost effective. In order to improve this, one must develop less expensive solar cells and/or increase their efficiency. Conventional solar cells will normally suffer a 70% loss from the incoming solar energy, among other things because the long-wavelength part of the sunlight is not absorbed. SunTune will exploit the long-wavelength light by effectively “tuning” the sunlight spectrum inside the solar cell to better match the range of efficient current generation. To achieve this, a method for the (up-) conversion of two low-energy photons into one high-energy photon (which can then generate current) will be developed. SunTune will optimize this process by employing advanced nanotechnology inside the solar cell. This will lead to an increased current generation – particularly during morning- and evening-light illumination, where the long-wavelength light is more abundant. The project investigates the underlying physical mecha¬nisms and develops materials, which support the most efficient conversion of light. The consor¬tium consists of a unique collection of Danish and international researchers with expertise of pivotal importance for the execution of the project, and of representatives from Danish companies, which are active in solar-cell manufacturing as well as in promoting their use for the production of electricity. SunTune will thus contribute to the goal of making Denmark independent of fossil fuels by 2050.