AMADEus Seminar - Prof. Wolfram Jaegermann - Friday 27 September 2013, 11:00 am - CRPP
Technische Universität Darmstadt, Institute of Materials Science, Surface Science Division, Petersenstrasse 32, D-64287 Darmstadt, Germany
Advanced Thin Film Solar Cells and Photoelectrochemical Cells for Fuel Production-Materials Science Challenges and Improved Device Structures
Abstract: It can be shown from a theoretical point of view that thin film p-i-n structures of highly absorbing compound semiconductors are most promising device structures for thin film solar cells. For improved future solar cells but also for H2O splitting photoelectrochemical cells tandem structures are needed.
Materials science challenges involve the control of nuclation and growth also at low substrate temperatures. Another decisive issue is related to adjusted interfaces which avoid Fermi level pinning at heterojunctions. For photoelectrochemical H2 evolving cells the alignment of semiconductor bands with the co-catalysts must be realized with minimized losses in photopotential and photocurrent.
First results on the preparation and characterisation of thin films and simple devices realized with different materials will be presented and discussed. In general, it is much easier to optimize bulk properties of the deposited materials. The prominent loss is usually due to not appropriate interfaces which lead to strongly reduced photovoltages.