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  Hempel, H.; Dennler, G.; Müller, S.; Larramona, G.; Eichberger, R.; Unold, T.: Charge Carrier Dynamics in Cu₂ZnSn(S/Se)₄ Thin Film Solar Cells measured by Time Resolved Terahertz and Microwave Spectroscopy. In: 2016 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz), 25-30 Sept. 2016 IEEE, 2016. - ISBN 978-1-4673-8485-8, p. 1-2

10.1109/IRMMW-THz.2016.7758693
Open Access Version

Abstract:
We track charge carriers dynamics from femtoseconds to nanoseconds in Cu2ZnSn(S/Se)4 thin films by time resolved terahertz spectroscopy (TRTS) and time resolved micro wave conductivity measurements (TRMC). This includes trapping of photo carriers into band tail states followed by recombination with a time constant of 9.1 ns. The relatively long life time is likely caused by the localization into long living trap states rather than by a low concentration of recombination centers.