Time-domain THz spectroscopy of electronic excitations in GaAs/AlGaAs superlattices


Time-domain THz spectroscopy of electronic excitations in GaAs/AlGaAs superlattices

Dreyhaupt, A.; Winnerl, S.; Dekorsy, T.; Helm, M.

We investigate the electronic properties of weakly and more strongly coupled n-doped GaAs/AlGaAs superlattices by time domain spectroscopy in the low frequency range from 0.5 to 3.5 THz. The sample properties are modulated either by applying an AC voltage via a gate electrode or by injecting a vertical current. The transmission signal is detected at the frequency of the modulation voltage with a lock-in amplifier leading to a signal-to-noise ratio superior compared to conventional FTIR spectroscopy in this frequency range. We will discuss the observation of inter-miniband transitions, confined donor transitions, plasmon excitations and the measurement of intra-miniband THz conductivity in a wide range of lattice temperatures.

Keywords: THz time-domain spectroscopy; semiconductor superlattice; interminiband-transition; intra-miniband THz conductivity

  • Lecture (Conference)
    DPG Frühjahrstagung, Fachverband Halbleiterphysik, HL 9.2, Regensburg 2004

Permalink: https://www.hzdr.de/publications/Publ-6594
Publ.-Id: 6594