Abstract
We investigated the magnetoconductivity and the Terahertz (THz) photo-conductivity of devices with HgTe quantum wells embedded in barrier layers of HgCdTe. For the photoconductivity measurements, a THz laser system (p-Ge-Laser) with tunable output in the wavelength range 120 um < lambda < 180 um was applied.
The THz laser radiation is used in order to excite charge carriers over the Landau-gap. The response of the sample to the laser impulses is in 2D-samples in the quantum Hall (QH) regime measured in order to receive data of the relaxation of the charge carriers.
In this presentation we present photoconduction measurements of the HgTe-quantum well in Hall bar, Corbino as well as combined Corbino-Hall bar geometry in the QH-regime. The material system HgTe/HgCdTe is characterized by a small effective mass compared to GaAs and accordingly smaller magnetic fields below 2 T for operation for the appropriate cyclotron energy.