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HL: Fachverband Halbleiterphysik
HL 84: Heterostructures and Interfaces
HL 84.9: Talk
Friday, March 24, 2017, 12:00–12:15, POT 151
The importance of interface step configurations in the GaP/Si(111):As system: Towards a growth model for twin domain formation — •Christian Koppka, Lars Winterfeld, Matthias Steidl, Agnieszka Paszuk, Peter Kleinschmidt, Erich Runge, and Thomas Hannappel — TU Ilmenau, Institute of Physics, D-98693 Ilmenau, Germany
V-III epitaxy on (111) oriented semiconductors is an increasingly relevant topic for innovative optoelectronic devices. In particular, the combination of (111) oriented epilayers with the growth of nanowire-based structures is a subject of intense research. However, the (111) orientation often leads to the formation of rotational twins. Despite the potential negative effects on the optoelectronic properties of such devices, this growth defect is rarely taken into account so far. Recently, we demonstrated the importance of the twin suppression in GaP/Si(111) virtual substrates for the quality of VLS grown GaP nanowires (1). Besides the nucleation conditions (Tnuc, tnuc, V/III ratio, etc.), the substrate misorientation has a decisive influence on the twin domain formation. For an atomistic understanding of the twinning process, DFT calculations on the GaP/Si(111):As interface, the twin boundary as well as nucleation at steps were performed. In addition to thermodynamic conditions, kinetic monte carlo simulations should also consider kinetic influences and confirm the experimentally determined trends.
(1) C. Koppka et al., Crystal Growth & Design (2016)