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Updated: May 22, 2026

Comprehensive Characterization of Extended Defects in Semiconductor Materials by a Scanning Electron Microscope
Published on: May 28, 2016
Quantum confinement dominates band gaps while defects lead the photoluminescence in silicon nanowires
Aarti Diwan1, Tharun J1, Chandeep Ec1
1Optics and Nanoelectronics Laboratory (ONE), Department of Physics and Nanotechnology, College of Engineering and Technology, SRM Institute of Science and Technology Kattankulathur Tamil Nadu 603203 India shailens@srmist.edu.in.
Abstract:
The quantum confinement effect has been observed in silicon nanowires (SiNWs) and is a widely accepted mechanism for visible photoluminescence (PL). Besides the observed widening of the band gap, an increase in Urbach energy is seen, revealing the presence of structural disorder due to oxygen-related defects. Surprisingly, in contrast to band gap widening, PL spectra showed a spectral shift instead of peak widening. Our finding indicates that oxygen-related defect states have a significant influence on the shifts in PL peaks. The combined influence of the quantum confinement effect and these defect states is demonstrated to play an important role in defining the PL response. This work provides insights into the interplay between quantum confinement and defect states, offering a clearer understanding of PL mechanisms in SiNWs.
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