SKM 2023 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 33: Poster II

HL 33.54: Poster

Wednesday, March 29, 2023, 17:00–19:00, P1

Fourier Transform Infrared Spectroscopy of Quantum Dot and Bragg Mirror Layers in Semiconductor Heterostructures — •Nikolaj Lehl, Andreas Wieck, Nathan Jukam, and Amar Alok — Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Deutschland

A purposefully designed distributed Bragg reflector (DBR) in a semiconductor heterostructure improves this device's photon yield gathered from its quantum dot (QD) layer. In this master thesis the transmission spectra of such semiconductor heterostructure samples are taken using Fourier-transform infrared spectroscopy (FTIR). The molecular beam epitaxy (MBE) grown gallium arsenide (GaAs) based samples include indium arsenide (InAs) QDs, and DBRs made of sequences of GaAs layers and aluminium arsenide (AlAs) layers. The DBR stopband measurements are taken in the near-infrared (NIR) and mid-infrared (MIR) region, in vacuum, under room temperature. Furthermore, it is planned to investigate the QD intersubband transitions implied in the far-infrared (FIR) transmission spectra as a function of applied voltage at liquid nitrogen and liquid helium temperatures. All acquired spectra are compared to the devices' simulated spectra, in order to make a conclusion on the initially expected growth rates and the growth rates resulting from the measurements.