December

Picture of the Month - December 2020

Here you see current insights into the research of the LaMa groups. A collection of the former pictures can be found in the Gallery.

Mg-doping yields Progress for ZnO-based Dye-sensitized Solar Cells

The image summarizes recent success in designing optimized semiconductors for dye-sensitized solar cells. Horizontal (vertical) arrows indicate the observed photocurrent (voltage), when Mg-doped ZnO nanoparticles that were prepared through wet-chemical synthesis with different Mg-content were used as photoanodes, sensitized by a dye and contacted by a redox electrolyte. The photovoltage was significantly increased by an upward shift of the quasi-Fermi level (and, presumably, of the conduction band edge) in the semiconductor. Electron transport was found to improve for low and worsen for higher Mg-concentrations. The recombination rate (represented by diagonal arrows) steadily increased with the amount of Mg. The superposition of these effects led to an increased cell performance for photoanodes, in which 5% of Zn was substituted by Mg (and to decreased performance for higher levels of doping).

This picture was submitted by Andreas Ringleb, group of Prof. Dr. Derck Schlettwein.