In the femtosecond laser lab of Dr. Dennis Friedrich at HZB, the transport homes of semiconductors can be determined using terahertz or microwave spectroscopy. For this function, a laser light pulse first delights the charge providers in the material, which are then irradiated with electro-magnetic waves (either THz or Microwave) and take in some of them. Credit: HZB
Lots of semiconducting materials are possible prospects for solar batteries. Recently, perovskite semiconductors in specific have actually drawn in attention, as they are both easy and inexpensive to process and allow high efficiencies. Now a study with 15 taking part research organizations demonstrates how terahertz (TRTS) and microwave spectroscopy (TRMC) can be used to dependably identify the mobility and lifetime of the charge providers in brand-new semiconducting materials. Using these measurement information it is possible to forecast the prospective efficiency of the solar battery in advance and to classify the losses in the finished cell.
The most crucial properties of a semiconductor to be utilized as a solar cell include the movement and lifetime of electrons and “holes.” Both quantities can be determined without contacts with spectroscopic approaches using terahertz or microwave radiation. Measurement information found in literature frequently differ by orders of magnitude. This has made it hard to use them for trusted assessments of material quality.
Referral samples measured
” We wished to get to the bottom of these distinctions, and gotten in touch with specialists from an overall of 15 worldwide labs to evaluate normal sources of mistake and problems with the measurements,” states Dr. Hannes Hempel from the HZB team led by Dr. Thomas Unold. The HZB physicists sent reference samples produced by the team of Dr. Martin Stolterfoht at University Potsdam to each lab with the perovskite semiconductor compound (Cs, FA, MA) Pb( I, Br) 3) optimised for stability.
In the femtosecond laser laboratory of Dr. Dennis Friedrich at HZB, the transportation properties of semiconductors can be determined utilizing terahertz or microwave spectroscopy. For this function, a laser light pulse very first delights the charge carriers in the material, which are then irradiated with electromagnetic waves (either THz or Microwave) and soak up some of them. Now a research study with 15 getting involved research study organizations reveals how terahertz (TRTS) and microwave spectroscopy (TRMC) can be utilized to dependably figure out the mobility and lifetime of the charge providers in brand-new semiconducting products. Both amounts can be measured without contacts with spectroscopic methods using terahertz or microwave radiation.
Much better data for better forecast
One result of the joint work is the substantially more accurate determination of the transport properties with terahertz or microwave spectroscopy. “We might determine some neuralgic points that have actually to be considered before the real measurements takes place, which allows us to reach significantly better arrangement of the outcomes,” Hempel highlights.
Another result of the research study: With reliable measurement information and an advanced analysis, the qualities of the solar cell can also be computed more exactly. “We think that this analysis is of great interest for photovoltaic research study, since it predicts the maximum possible effectiveness of the material in a solar battery and reveals the impact of various loss mechanisms, such as transport barriers,” says Unold. This applies not just to the product class of perovskite semiconductors, however also to other new semiconducting products, which can therefore be tested quicker for their prospective suitability.
Referral: “Predicting Solar Cell Performance from Terahertz and Microwave Spectroscopy” by Hannes Hempel, Tom J. Savenjie, Martin Stolterfoht, Jens Neu, Michele Failla, Vaisakh C. Paingad, Petr Kužel, Edwin J. Heilweil, Jacob A. Spies, Markus Schleuning, Jiashang Zhao, Dennis Friedrich, Klaus Schwarzburg, Laurens D.A. Siebbeles, Patrick Dörflinger, Vladimir Dyakonov, Ryuzi Katoh, Min Ji Hong, John G. Labram, Maurizio Monti, Edward Butler-Caddle, James Lloyd-Hughes, Mohammad M. Taheri, Jason B. Baxter, Timothy J. Magnanelli, Simon Luo, Joseph M. Cardon, Shane Ardo and Thomas Unold, 26 February 2022, Advanced Energy Materials.DOI: 10.1002/ aenm.202102776.