2011/03/29 by M. Fehr, Matthias Fehr, Alexander Schnegg +25
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Silicon Nanostructures and Photoluminescence #Silicon and Solar Cell Technologies #Thin-Film Transistor Technologies #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.1103.5641
26 pages, 4 figures, 1 table, revised version
openalex publication_date 2011/03/29 · arxiv created 2011/09/17 · arxiv updated 2011/09/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Multifrequency pulsed electron paramagnetic resonance (EPR) spectroscopy using S-, X-, Q- and W-Band frequencies (3.6, 9.7, 34, and 94 GHz, respectively) was employed to study paramagnetic coordination defects in undoped hydrogenated amorphous silicon (a-Si:H). The improved spectral resolution at high magnetic field reveals a rhombic splitting of the g-tensor with the following principal values: gx=2.0079, gy=2.0061 and gz=2.0034 and shows pronounced g-strain, i.e., the principal values are widely distributed. The multifrequency approach furthermore yields precise 29Si hyperfine data. Density functional theory (DFT) calculations on 26 computer-generated a-Si:H dangling-bond models yielded g-values close to the experimental data but deviating hyperfine interaction values. We show that paramagnetic coordination defects in a-Si:H are more delocalized than computer-generated dangling-bond defects and discuss models to explain this discrepancy.