Minority and Majority Charge Carrier Mobility in Cu2ZnSnSe4 revealed by Terahertz Spectroscopy

Hempel, Hannes; Hages, Charles J.; Eichberger, Rainer; Repins, Ingrid L.; Unold, Thomas

doi:10.1038/s41598-018-32695-6

Minority and Majority Charge Carrier Mobility in Cu₂ZnSnSe₄ revealed by Terahertz Spectroscopy

Journal Article · Thu Sep 27 00:00:00 EDT 2018 · Scientific Reports

DOI:https://doi.org/10.1038/s41598-018-32695-6· OSTI ID:1476709

Hempel, Hannes ^[1]; Hages, Charles J. ^[1]; Eichberger, Rainer ^[1]; Repins, Ingrid L. ^[2]; ^[1]

Helmholtz-Zentrum Berlin fur Materialien und Energie GmbH, Berlin (Germany)
National Renewable Energy Lab. (NREL), Golden, CO (United States)

Here, the mobilities of electrons and holes determine the applicability of any semiconductor, but their individual measurement remains a major challenge. Here, we show that time-resolved terahertz spectroscopy (TRTS) can distinguish the mobilities of minority and majority charge carriers independently of the doping-type and without electrical contacts. To this end, we combine the well-established determination of the sum of electron and hole mobilities from photo-induced THz absorption spectra with mobility-dependent ambipolar modeling of TRTS transients. The method is demonstrated on a polycrystalline Cu₂ZnSnSe₄ thin film and reveals a minority (electron) mobility of 128 cm²/V-s and a majority (hole) carrier mobility of 7 cm²/V-s in the vertical transport direction relevant for light emitting, photovoltaic and solar water splitting devices. Additionally, the TRTS analysis yields an effective bulk carrier lifetime of 4.4 ns, a surface recombination velocity of 6 * 10⁴ cm/s and a doping concentration of ca. 10¹⁶ cm^-3, thus offering the potential for contactless screen novel optoelectronic materials.

View Accepted Manuscript (DOE)

Research Organization:: National Renewable Energy Laboratory (NREL), Golden, CO (United States)

Sponsoring Organization:: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)

Grant/Contract Number:: AC36-08GO28308

OSTI ID:: 1476709

Report Number(s):: NREL/JA--5K00-72460

Journal Information:: Scientific Reports, Journal Name: Scientific Reports Journal Issue: 1 Vol. 8; ISSN 2045-2322

Publisher:: Nature Publishing GroupCopyright Statement

Country of Publication:: United States

Language:: English

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Cited By (3)

Influence of Germanium Content on the Properties of Cu 2 Zn(SnGe)Se 4 Thin Films Deposited by Sequential Thermal Evaporation Technique Studied by Photoacoustic Technique Vigil-Galán, Osvaldo; González-Castillo, Jesús Roberto; Macias, Marcos physica status solidi (a), Vol. 216, Issue 18 https://doi.org/10.1002/pssa.201900260	journal	July 2019
Bulk and surface recombination properties in thin film semiconductors with different surface treatments from time-resolved photoluminescence measurements Weiss, Thomas P.; Bissig, Benjamin; Feurer, Thomas Scientific Reports, Vol. 9, Issue 1 https://doi.org/10.1038/s41598-019-41716-x	journal	March 2019
The electrical and optical properties of kesterites Grossberg, Maarja; Krustok, Jüri; Hages, Charles J. Journal of Physics: Energy, Vol. 1, Issue 4 https://doi.org/10.1088/2515-7655/ab29a0	journal	August 2019

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Related Subjects

36 MATERIALS SCIENCE
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CZTS
kesterite
mobility
spectroscopy
terahertz