Length dependent optical characteristics analysis for semiconductor nanowires
| Autor: | Navneet Dhindsa, Simarjeet S. Saini, Reza Kohandani |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Silicon Nanowire Physics::Optics chemistry.chemical_element Bioengineering 02 engineering and technology 010402 general chemistry 01 natural sciences Molecular physics Gallium arsenide Condensed Matter::Materials Science chemistry.chemical_compound General Materials Science Electrical and Electronic Engineering Absorption (electromagnetic radiation) business.industry Scattering Mechanical Engineering General Chemistry Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Ray 0104 chemical sciences Wavelength Semiconductor chemistry Mechanics of Materials 0210 nano-technology business |
| Zdroj: | Nanotechnology. 31:224001 |
| ISSN: | 1361-6528 0957-4484 |
| DOI: | 10.1088/1361-6528/ab764a |
| Popis: | Resonant optical mode excitations in semiconductor nanowires result in enhanced absorptions. Nominally, only the diameter dependent radial mode excitations have been considered for the increased absorption. In this paper, we try to understand how the length of the nanowires affects the resonant wavelength and peak absorption wavelengths. We answer two questions viz (1) at what minimum length are radial optical modes stabilized and dominate the absorption characteristics and (2) do longitudinal modes play a role in absorption characteristics especially in determining the resonant wavelength. Two different semiconductors are studied viz silicon and gallium arsenide. We find that even nanowires as short as 200 nm exhibit absorption characteristics dominated by the radial mode excitation. However, for lengths smaller than 200 nm, the optical characteristics are dominated by scattering. Further, we observe that longitudinal modes are excited in low absorption semiconductor materials like silicon for lengths up to 700 nm and the absorption peak depends both on the diameter and the wavelength. Further, shorter length nanowires may have higher absorption than the longer ones in this regime. We also observed that scattering from the nanowires is less than 2% of the incident light. For higher absorption semiconductor like GaAs, absorption characteristics are mainly determined by the radial mode excitations even for shorter lengths. The results provide further insight into the radial mode excitations in semiconductor nanowires. |
| Databáze: | OpenAIRE |
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