Vortrag von Prof. Alex Quandt, University of the Witwatersrand, Johannesburg, South Africa im Rahmen des Greifswalder Physikalischen Kolloquiums.
South Africa is one of the solar hot spots in the world, which means that solar power is an energy resource that is abundant everywhere in the country. Therefore, unlike other countries in less sunny regions of the world, the future energy landscape in South Africa will have a strong solar component. A lot of our current research goes into robust, cheap and highly efficient photovoltaic devices, in order to serve the least developed parts of the country with electricity, which have traditionally been off-grid in the past. This research is part of a much larger global trend within the field of photovoltaics, which aims a more efficient light management, mainly by augmenting the basic semiconductor heterojunctions with novel photonic and plasmonic elements.
I will give a short introduction to the surprisingly long story of solar cells, and describe some of the theoretical and practical efficiency limits involved. I will explain and show examples of plasmon enhanced solar cells for nanoscale light concentration, as well as of solar cells that use up- and down-conversion layers for harvesting photons outside the typical frequency range of conventional solar cells. Finally I will describe the theoretical and numerical modeling of fundamental light-matter interactions in solar cells, and indicate how first principles data can be used to simulate and develop photovoltaic devices from the bottom up.