Study Over Electronic and Optical Properties of Semiconductors in Nanometric Regime

H.I. Ikeri¹ , V.M. Adokor² , N.N. Tasie³

1. Department of Physics, Kingsley Ozumba Mbadiwe University.
2. Federal College of Education Omoku Rivers State.
3. Department of Physics, Rivers State University.

Section:Research Paper, Product Type: Journal-Paper
Vol.9 , Issue.3 , pp.1-7, Dec-2022

Online published on Dec 31, 2022

Copyright © H.I. Ikeri, V.M. Adokor, N.N. Tasie . This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
 

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Abstract :
Electronic and optical properties of semiconductors in nanometric regime have been simulated using the potential well concept and solving 3D Schrodinger equation. We calculated the optical bandgap and wavelength for varying sizes of semiconductor quantum dots QDs. The result shows a size-dependent absorption and fluorescence spectra with discrete electronic transitions that can be modified by size modulation. As a result, they exhibit excellent photoelectronic properties, including broad excitation spectra with narrow emission bands, and so can be used for multiplexed detection without overlap of spectral emission. They also possess wide band bandgap energies and have shown significant changes in their optical transitions with bandgap tuning. This illustration is in the outstanding blueshift of absorption bands as well as the photoluminescence spectra with decreasing size. These properties represent a signature of discrete electronic state, which is, in turn, a direct consequence of the quantum confinement effect. The optical spectra observed for CdSe and CdS QDs span nearly the entire visible region which makes them excellent fluorescent materials for improving display performance such as color gamut. In addition, near-infrared (NIR) waveband also observed in CdSe and CdS QDs cover the biological transparency windows and are widely explored for biological imaging applications following their deeper tissue penetration and higher spatial resolution compare to visible probes. The optical waveband observed in InAs, InSb QDs covers the short-wavelength infrared spectral region suitable for optical communication operating exclusively in C-band, at which chromatic dispersion and transmission losses in optical fibers are at a respective minimum. Furthermore, InAs, InSb QDs strongly indicate spectrum covering the important atmospheric transmission windows where attenuation of electromagnetic wave is extremely low particularly for free space communications. It is found that PbS, PbSe and PbSe QDs display exceptional optical trait that can be tuned throughout UV to IR wavebands, favorable for quantitative gain in solar cells applications.

Key-Words / Index Term :
Semiconductor nanocrystals, confinement, potential well, Schrodinger equation, electronic and optical properties

References :
[1] Y. W. Jun, C. S. Choi, and J. Cheon. Size and shape controlled ZnTe nanocrystals with quantum confinement effect. Chem. Commun. 7(1): 101–102, 2001.
[2] A. I. Onyia, H. I. Ikeri, and A. I. Chima. Surface and Quantum Effects in Nanosized Semiconductor, American Journal of Nano Research and Applications. Vol. 8, No. 3, pp. 35-41, 2020.
[3] S. T. Harry, and M. A. Adekanmbi. Confinement Energy of Quantum Dots and the Brus Equation. International Journal of Research -Granthaalayah, 8(11), 318-323, 2020.
[4] M. Cardona, and Y. Peter. Fundamentals of semiconductors, fourth edition, springer. 2013
[5] U. Bockelmann. Exciton relaxation and radiative recombination in semiconductor quantum dots. Physical Review B-Condensed Matter, 48(23): 17637- 17640, 1993.
[6] Y. Arakawa, Y. Nagamune, M. Nishioka, and S. Tsukamoto. Physics of semiconductor. Journal of Science and Technology, 8(6): 1082- 1088, 1993.
[7] E. Chukwuocha, and M. Onyeaju. Effect of quantum confinement on the wavelength of CdSe quantum dots. International journal of science and technology research, 1(7): 21 – 24, 2012.
[8] P. Nisha, and D. Amrita. Theoretical study of dependence of wavelength on size of quantum dot. Intl Journal of Scientific Research and Development, 4(1): 126 – 130, 2016.
[9] H. Davies. The physics of low dimensional semiconductors; an introduction (6th Reprint Ed.) Cambridge university press, 234, 2006.
[10] S. Madan, G. Monika, and D. Kamal. Size and shape effects on the band gap of semiconductor compound nanomaterials. Journal of Taibah University for Science, 12(4): 470-475, 2018.
[11] J. Harbold, and P. Monica. The electronic and optical properties of colloidal lead selenide semiconductor nanocrystal: Ph.D. dissertation. Cornel University. Ithaca, New York. 2008.
[12] H. I. Ikeri, and A. I. Onyia. Theoretical investigation of size effect on energy gap of quantum dots using particle in a box model. Chalcogenide Letters, 14(2): 49 – 54, 2017.
[13] H. I. Ikeri, A. I. Onyia, and P. U. Asogwa. Investigation of optical properties of quantum dots for multiple junction solar cells applications. Intl. Journal of scientific and technology, 8(10): 3531 – 3535, 2019.
[14] L. E. Brus. Electron-electron and electron-hole interactions in small semiconductor crystallites: the size dependence of the lowest excited electronic state. The Journal of ChemicalPhysics, 80(9): 403-4409, 1984.
[15] C. Delerue, and M. Lannoo. Nanostructures: Theory and modelling. India: Springer, 245 – 265, 2004.
[16] G. Jia. Excitons properties and quantum confinement in CdS/ZnS core/shell quantum dots. Opt. Adv. Mater, 5: 738–741, 2011.
[17] H. I. Ikeri, and A. I. Onyia. Formulation of exciton in a quantum box model for multiple exciton solar cell application. Intl. Journal of Scientific Research in Physics and Applied Science, 7(2): 12 – 16, 2020.