Solar cells are team players - tandem solar cells for higher efficiency

In order to mitigate the effects of the climate crisis a rapid transition of the global energy production to renewable sources is necessary. Many technologies will play a role in this transition, and photovoltaics (PV) will certainly be one of the cornerstone technologies in the future energy mixture. The price per installed watt is a key parameter for the competitiveness of PV technology in the energy market. One approach to reduce this figure is to increase the device efficiency. The current PV market is dominated by devices based on silicon, but silicon PV technology is approaching its practical efficiency limit. To achieve higher efficiencies the development of tandem solar cells is the most promising path forward. This lecture gives an introduction to tandem and multi junction solar cells. The explanations for higher potential efficiencies will be discussed and we will explore the technical implementations of this promising technology.