In the face of climate change, we are challenged to meet our energy needs using new, carbon-neutral methods. Given this premise, renewable energy sources such as wind power and photovoltaics are the most promising technologies for generating the majority of the energy we need. Photovoltaics in particular—that is, the conversion of sunlight into electricity using solar cells—offers great potential in this regard. Today’s solar modules are based on silicon, which is the second most abundant element in the Earth’s crust after oxygen, and reliably deliver electrical energy. The latest silicon solar cells achieve an efficiency of 25% in practice and have thus nearly reached their theoretical maximum of 30%. However, to meet rising energy demand without covering every available surface with photovoltaic systems, solar cells with an efficiency exceeding 30% are needed.
The question of “Solar Cell 2.0” has therefore been pressing for several years. The search for a technology that enables the conversion of as much of the sun’s energy as possible into electrical energy in practice led to the discovery of perovskites as an active material. These so-called perovskite solar cells show enormous potential, especially when combined with silicon solar cells. Efficiency levels exceeding 35% have already been achieved in so-called tandem solar cells. This presentation explores the ongoing success story of photovoltaics and the exciting prospects that perovskite solar cells offer for the future.