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Bhandari KP, Sapkota DR, Jamarkattel MK, Stillion Q, Collins RW. Zinc Oxide Nanoparticles-Solution-Based Synthesis and Characterizations. Nanomaterials (Basel) 2023; 13:nano13111795. [PMID: 37299698 DOI: 10.3390/nano13111795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 05/26/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023]
Abstract
Zinc oxide (ZnO) nanoparticles have shown great potential because of their versatile and promising applications in different fields, including solar cells. Various methods of synthesizing ZnO materials have been reported. In this work, controlled synthesis of ZnO nanoparticles was achieved via a simple, cost-effective, and facile synthetic method. Using transmittance spectra and film thickness of ZnO, the optical band gap energies were calculated. For as-synthesized and annealed ZnO films, the bandgap energies were found to be 3.40 eV and 3.30 eV, respectively. The nature of the optical transition indicates that the material is a direct bandgap semiconductor. Spectroscopic ellipsometry (SE) analysis was used to extract dielectric functions where the onset of optical absorption of ZnO was observed at lower photon energy due to annealing of the nanoparticle film. Similarly, X-ray diffraction (XRD) and scanning electron microscopy (SEM) data revealed that the material is pure and crystalline in nature, with the average crystallite size of ~9 nm.
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Affiliation(s)
- Khagendra P Bhandari
- Department of Physics and Astronomy, Ohio Northern University, Ada, OH 45810, USA
| | - Dhurba R Sapkota
- Wright Center for Photovoltaics Innovation & Commercialization, University of Toledo, Toledo, OH 43606, USA
| | - Manoj K Jamarkattel
- Wright Center for Photovoltaics Innovation & Commercialization, University of Toledo, Toledo, OH 43606, USA
| | - Quenton Stillion
- Department of Physics and Astronomy, Ohio Northern University, Ada, OH 45810, USA
| | - Robert W Collins
- Wright Center for Photovoltaics Innovation & Commercialization, University of Toledo, Toledo, OH 43606, USA
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Alaani MAR, Koirala P, Phillips AB, Liyanage GK, Awni RA, Sapkota DR, Ramanujam B, Heben MJ, O’Leary SK, Podraza NJ, Collins RW. Optical Properties of Magnesium-Zinc Oxide for Thin Film Photovoltaics. Materials (Basel) 2021; 14:ma14195649. [PMID: 34640041 PMCID: PMC8510442 DOI: 10.3390/ma14195649] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 09/20/2021] [Accepted: 09/23/2021] [Indexed: 12/28/2022]
Abstract
Motivated by their utility in CdTe-based thin film photovoltaics (PV) devices, an investigation of thin films of the magnesium-zinc oxide (MgxZn1−xO or MZO) alloy system was undertaken applying spectroscopic ellipsometry (SE). Dominant wurtzite phase MZO thin films with Mg contents in the range 0 ≤ x ≤ 0.42 were deposited on room temperature soda lime glass (SLG) substrates by magnetron co-sputtering of MgO and ZnO targets followed by annealing. The complex dielectric functions ε of these films were determined and parameterized over the photon energy range from 0.73 to 6.5 eV using an analytical model consisting of two critical point (CP) oscillators. The CP parameters in this model are expressed as polynomial functions of the best fitting lowest CP energy or bandgap E0 = Eg, which in turn is a quadratic function of x. As functions of x, both the lowest energy CP broadening and the Urbach parameter show minima for x ~ 0.3, which corresponds to a bandgap of 3.65 eV. As a result, it is concluded that for this composition and bandgap, the MZO exhibits either a minimum concentration of defects in the bulk of the crystallites or a maximum in the grain size, an observation consistent with measured X-ray diffraction line broadenings. The parametric expression for ε developed here is expected to be useful in future mapping and through-the-glass SE analyses of partial and complete PV device structures incorporating MZO.
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Affiliation(s)
- Mohammed A. Razooqi Alaani
- Wright Center for Photovoltaics Innovation & Commercialization, Department of Physics & Astronomy, University of Toledo, Toledo, OH 43606, USA; (P.K.); (A.B.P.); (G.K.L.); (R.A.A.); (D.R.S.); (B.R.); (M.J.H.)
- Correspondence: (M.A.R.A.); (N.J.P.); (R.W.C.)
| | - Prakash Koirala
- Wright Center for Photovoltaics Innovation & Commercialization, Department of Physics & Astronomy, University of Toledo, Toledo, OH 43606, USA; (P.K.); (A.B.P.); (G.K.L.); (R.A.A.); (D.R.S.); (B.R.); (M.J.H.)
| | - Adam B. Phillips
- Wright Center for Photovoltaics Innovation & Commercialization, Department of Physics & Astronomy, University of Toledo, Toledo, OH 43606, USA; (P.K.); (A.B.P.); (G.K.L.); (R.A.A.); (D.R.S.); (B.R.); (M.J.H.)
| | - Geethika K. Liyanage
- Wright Center for Photovoltaics Innovation & Commercialization, Department of Physics & Astronomy, University of Toledo, Toledo, OH 43606, USA; (P.K.); (A.B.P.); (G.K.L.); (R.A.A.); (D.R.S.); (B.R.); (M.J.H.)
| | - Rasha A. Awni
- Wright Center for Photovoltaics Innovation & Commercialization, Department of Physics & Astronomy, University of Toledo, Toledo, OH 43606, USA; (P.K.); (A.B.P.); (G.K.L.); (R.A.A.); (D.R.S.); (B.R.); (M.J.H.)
| | - Dhurba R. Sapkota
- Wright Center for Photovoltaics Innovation & Commercialization, Department of Physics & Astronomy, University of Toledo, Toledo, OH 43606, USA; (P.K.); (A.B.P.); (G.K.L.); (R.A.A.); (D.R.S.); (B.R.); (M.J.H.)
| | - Balaji Ramanujam
- Wright Center for Photovoltaics Innovation & Commercialization, Department of Physics & Astronomy, University of Toledo, Toledo, OH 43606, USA; (P.K.); (A.B.P.); (G.K.L.); (R.A.A.); (D.R.S.); (B.R.); (M.J.H.)
| | - Michael J. Heben
- Wright Center for Photovoltaics Innovation & Commercialization, Department of Physics & Astronomy, University of Toledo, Toledo, OH 43606, USA; (P.K.); (A.B.P.); (G.K.L.); (R.A.A.); (D.R.S.); (B.R.); (M.J.H.)
| | - Stephen K. O’Leary
- School of Engineering, The University of British Columbia Okanagan, 3333 University Way, Kelowna, BC V1V 1V7, Canada;
| | - Nikolas J. Podraza
- Wright Center for Photovoltaics Innovation & Commercialization, Department of Physics & Astronomy, University of Toledo, Toledo, OH 43606, USA; (P.K.); (A.B.P.); (G.K.L.); (R.A.A.); (D.R.S.); (B.R.); (M.J.H.)
- Correspondence: (M.A.R.A.); (N.J.P.); (R.W.C.)
| | - Robert W. Collins
- Wright Center for Photovoltaics Innovation & Commercialization, Department of Physics & Astronomy, University of Toledo, Toledo, OH 43606, USA; (P.K.); (A.B.P.); (G.K.L.); (R.A.A.); (D.R.S.); (B.R.); (M.J.H.)
- Correspondence: (M.A.R.A.); (N.J.P.); (R.W.C.)
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Shrestha N, Sapkota DR, Subedi KK, Pradhan P, Koirala P, Phillips AB, Collins RW, Heben MJ, Ellingson RJ. Identification of Defect Levels in Copper Indium Diselenide (CuInSe2) Thin Films via Photoluminescence Studies. ACTA ACUST UNITED AC 2018. [DOI: 10.1557/adv.2018.556] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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