Perovskite Silicon Tandem Solar Cells

In this thesis perovskite solar cells are optimized as top solar cells in perovskite silicon tandem devices. The key aspects are the development of a low-temperature process for the electron contact and the optimization of the sputter process for a transparent conductive oxide as front side contact. These top solar cells are combined with silicon heterojunction solar cells yielding in a two-terminal tandem efficiency of 23.4%.

---

Single junction solar cells are limited by spectral losses. Thermalization losses can be reduced with tandem solar cells. In this thesis perovskite solar cells in the regular n-i-p architecture are optimized for the use as top solar cells in combination with silicon bottom solar cells. A low-temperature process is developed for the titanium dioxide electron contact. Additionally, a soft sputter process is optimized for indium tin oxide allowing for direct deposition of this transparent conductive oxide on the hole contact without any buffer layer. The optimized perovskite solar cells are combined with silicon heterojunction solar cells. These monolithic tandem devices reach power conversion efficiencies up to 23.4%.