SKM 2021 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 16: Semiconductors: Optical, Transport and Ultrafast Properties

HL 16.4: Vortrag

Donnerstag, 30. September 2021, 12:00–12:15, H1

Hydrogen-Bonding Ability of the GaAs (001) Surface — •Marsel Karmo and Erich Runge — Technische Universität Ilmenau

Thin films of direct-band gap III-V-semiconductors are widely used in optoelectronic devices such as lasers or solar cells. Their production via MOVPE/MOCVD involves hydrogen, which may or may not bind to the semiconductor surface. We study the hydrogen-bonding ability of the paradigmatic GaAs (001) surface via DFT using the VASP code. From the calculated thermodynamic potentials, we derive the phase diagram for the surface reconstructions as function of the availability of hydrogen and arsenic. Furthermore, we calculate the potential surface energy (PES) for a single adsorbed hydrogen which gives information about potential hydrogen bonding sites. For a wide range of the surface chemical potentials the (2x2)-surface with one hydrogen adsorbed to each As-dimer is energetically favored.