Dresden 2017 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 74: Group IV: Si/Ge/SiC
HL 74.3: Vortrag
Donnerstag, 23. März 2017, 12:30–12:45, POT 06
Investigation of 3C-SiC/SiO2 interfacial point defects from ab initio g-tensor calculations and electron paramagnetic resonance measurements — •T. A. Nugraha1,2, M. Rohrmüller2, U. Gerstmann2, S. Greulich-Weber3, A. Stellhorn2, J. L. Cantin4, J. Von Bardeleben4, W. G. Schmidt2, and S. Wippermann1 — 1Max-Planck-Institut für Eisenforschung — 2University of Paderborn — 3Solar Weaver GmbH — 4Pierre and Marie Curie University
SiC is widely used in high-power, high-frequency electronic devices. Recently, it has also been used in nanocomposites as light absorbers in solar energy conversion devices. Analogous to Si, SiC features SiO2 as native oxide that can be used for passivation and insulating layers. However, a significant number of defect states are reported to form at SiC/SiO2 interfaces, limiting mobility and increasing recombination of free charge carriers. We investigated the growth of oxide on different 3C-SiC surfaces from first principles. Carbon antisite Csi defects are found to be strongly stabilized in particular at the interface, because carbon changes its hybridization from sp3 in the SiC-bulk to sp2 at the interface, creating a dangling bond inside a porous region of the SiO2 passivating layer. Combining ab initio g-tensor calculations and electron paramagnetic resonance (EPR) measurements, we show that Csi defects explain the measured EPR signatures, while the hyperfine structure allows to obtain local structural information of the oxide layer. Financial support from BMBF NanoMatFutur grant 13N12972 and DFG priority program SPP-1601 is gratefully acknowledged.