Detection of THz radiation with devices made from wafers with HgTe and InSb quantum wells

Gouider, F., Vasilyev, Yu. B., Konemann, J., Buckle, Philip Derek ORCID: https://orcid.org/0000-0001-9508-7783, Brune, C., Buhmann, H., Nachtwei, G., Ihm, Jisoon and Cheong, Hyeonsik 2011. Detection of THz radiation with devices made from wafers with HgTe and InSb quantum wells. Presented at: Physics of Semiconductors : 30th International Conference on the Physics of Semiconductors, Seoul, Korea, 25-30 July 2010. Proceedings of the 30th International Conference on the Physics of Semiconductors, Seoul, Korea, 25-30 July 2010. , vol.1399 Melville, NY: American Institute of Physics, pp. 1019-1020. 10.1063/1.3666725

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Abstract

In this study we present measurements of the Terahertz (THz) photoconductivity of 2D electron system realized at HgTe∕HgCdTe and AlInSb∕InSb∕AlInSb quantum wells (QWs) in Corbino geometry (inner and outer radius: 500 μm and 1500 μm) with different mobilities and electron densities. To characterize the devices, the Shubnikov‐de Haas (SdH) effect up to magnetic fields B of 7T and current‐voltage (I‐V) characteristics at various magnetic fields were measured. The THz radiation is provided by a p‐Ge laser which operates with a magnetic field and a high voltage for the electrical pumping. The stimulated emission is caused by transistions between Landau levels of light holes [1]. The laser is tunable in the range between 1.7 to 2.5 THz (corresponding to wavelengths between 120 to 180 μm or energies of 7 to 12 meV). The laser is pulsed with a pulse rate of 1 Hz and pulse lengths of about 1 μs with low switching times (about 20 ns). The monochromatic THz radiaton is tranferred to our samples via a 0.32m long brass waveguide immersed in liquid Helium. The detection of a change in the conductivity of the sample due to absorption of THz‐radiation (photoresponse) requires a low‐noise circuit. For the Corbino‐shaped samples the photoresponse (PR) is measured via a resistor RV of 1 kΩ. The signal is transferred via in a high‐frequency cable and detected with a digital oscilloscope.

Item Type:	Conference or Workshop Item (Paper)
Date Type:	Publication
Status:	Published
Schools:	Physics and Astronomy
Subjects:	Q Science > QC Physics
Uncontrolled Keywords:	Quantum wells ; Electron density ; Resistors ; Molecular beam epitaxial growth
Publisher:	American Institute of Physics
ISBN:	9780735410022
ISSN:	0094-243X
Last Modified:	19 May 2023 01:37
URI:	https://orca.cardiff.ac.uk/id/eprint/17443

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