Photoluminescence Spectra From The Direct Energy Gap of a-SiQDs

A theoretical model for radiative recombination in amorphous silicon quantum dots (a-SiQDs) was developed. In this model, for the first time, the coexistence of both spatial and quantum confinements were considered. Also, it is found that the photoluminescence exhibits significant size dependence in...

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Bibliographic Details
Published in:Journal of physics. Conference series 2018-05, Vol.1003 (1), p.12105
Main Authors: Abdul-Ameer, Nidhal M., Abdulrida, Moafak C., Abdul-Hakeem, Shatha M.
Format: Article
Language:English
Subjects:
Amorphous silicon
Blue shift
Confinement
Density
Doppler effect
Efficiency
Emission spectra
Energy gap
Light emission
Photoluminescence
Photovoltaic cells
Physics
Quantum confinement
Quantum Dots
Quantum efficiency
Radiative recombination
Red shift
Room temperature
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Summary:A theoretical model for radiative recombination in amorphous silicon quantum dots (a-SiQDs) was developed. In this model, for the first time, the coexistence of both spatial and quantum confinements were considered. Also, it is found that the photoluminescence exhibits significant size dependence in the range (1-4) nm of the quantum dots. a-SiQDs show visible light emission peak energies and high radiative quantum efficiency at room temperature,in contrast to bulk a-Si structures. The quantum efficiency is sensitive to any change in defect density (the volume nonradiative centers density and/or the surface nonradiative centers density) but, with small dots sizes, the quantum efficiency is insensitive to such defects. Our analysis shows that the photoluminescence intensity increases or decreases by the effect of radiative quantum efficiency. By controlling the size of a-SiQDs, we note that the energy of emission can be tuned. The blue shift is attributed to quantum confinement effect. Meanwhile, the spatial confinement effect is clearly observed in red shift in emission spectra. we found a good agreement with the experimental published data. Therefore, we assert that a-SiQDs material is a promising candidate for visible, tunable, and high performance devices of light emitting.
ISSN:1742-6588
1742-6596
DOI:10.1088/1742-6596/1003/1/012105