Berlin 2015 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 93: III-V semiconductors (other than nitrides)

HL 93.2: Talk

Thursday, March 19, 2015, 16:00–16:15, EW 203

Capture cross sections from first-principles total energy calculations for oxygen in GaP as benchmark case — •Ying Cui, Christoph Freysoldt, and Jörg Neugebauer — Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, 40627 Düsseldorf

Non-radiative recombination is of particular technological importance for optoelectronic devices. The mechanism is however far from well understood. The Shockley-Read-Hall model is usually applied to explain thermally activated recombination at deep defects. Capture cross sections are key parameters in this model. We present a theoretical approach to compute the capture cross sections by using density functional theory with hybrid functional (HSE). In our approach the transition state in the capture process is located by using defect level occupation as a natural reaction coordinate. To benchmark theory against experiment, we apply our method to substitutional oxygen in GaP for which accurate DLTS data is available. We find a good agreement for capture cross sections as well as optical transition energies. Our method to determine capture cross sections is universal and can be applied to materials beyond GaP.