Many semiconducting materials are likely to be utilized for solar cells. In recent years, perovskite semiconductors have resold attention, which are both inexpensive and easy to process and provide high performance. Currently, a study with 15 participating research institutions has demonstrated how terahertz (TRTS) and microwave spectroscopy (TRMC) can be used to reliably determine the mobility and lifetime of the charge carriers in new semiconducting materials. This is by combining these measures to measure the potential
Both quantities can be measured without contact with terahertz or microwave radiation, but measurements have been often different by magnitude. This has made it difficult to use them for reliable material quality assessments.
Reference samples measured
"We wanted to get to the bottom of these differences, and we contacted experts from a total of 15 international laboratories to investigate common sources of error and problems with measurements," said Dr. Martin Stolterfoht of the HZB team. The perovskite semiconductor compound (Cs,FA,MA)Pb(I,Br) has been restructured for stability.
Better data for better prediction
One consequence of the combined work is the significantly more precise terahertz or microwave spectroscopy determination of transport properties. "We may identify some neuralgic points that must be examined before the actual measurements begin, which allows us to reach significant better agreement of the results."
Another conclusion of the study: With reliable measurement data and a more advanced analysis, the characteristics of the solar cell can be also calculated more precisely. "We believe this study is of great interest for photovoltaic research, because it predicts the maximum possible potential efficiency of the material in a solar cell and highlights the potential benefits of various loss mechanisms, such as transport barriers," says Unold. This applies not only to the material class of perovskite semiconductors, but also to other new semiconducting materials, which can thus