Determination of optical bandgap energy and optical characteristics of Cd30Se50S20 thin film at various thicknesses

2022 ◽  
Vol 148 ◽  
pp. 107770
Author(s):  
Ammar Qasem ◽  
Mohamed S. Mostafa ◽  
H.A. Yakout ◽  
Mona Mahmoud ◽  
E.R. Shaaban
Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1639
Author(s):  
Mithun Bhowmick ◽  
Haowen Xi ◽  
Bruno Ullrich

We are reporting an esoteric method to determine the optical bandgap of direct gap materials by employing Urbach’s rule. The latter, which describes the slope of the band tail absorption in semiconductors, in its original version, cannot be employed to pinpoint the optical bandgap. Herein, however, we show that a modified form of Urbach’s rule defines the optical bandgap, and therefore, enables the accurate determination of the optical bandgap energy, which turns out to be identical with the threshold energy for the band tail absorption. The model further produces an explicit expression for the absorption coefficient at the optical bandgap energy.


2013 ◽  
Vol 665 ◽  
pp. 159-167
Author(s):  
M.S. Jani ◽  
H.S. Patel ◽  
J.R. Rathod ◽  
K.D. Patel ◽  
V.M. Pathak ◽  
...  

In this paper structural and optical properties of CdSe thin films with different thickness deposited by thermal evaporation under vacuum onto glass substrates are presented. The structural investigations performed by means of XRD technique showed that the films have a polycrystalline and hexagonal (würtzite) structure. The values of some important parameters of the studied films (absorption coefficient and optical bandgap energy) are determined from transmission spectra. The values of the optical bandgap energy (Eg) calculated from the absorption spectra, ranged between 1.67 - 1.74 eV.


2019 ◽  
Vol 181 ◽  
pp. 460-469 ◽  
Author(s):  
Se-Yun Kim ◽  
Ho-Chang Lee ◽  
Yujin Nam ◽  
Yeonghun Yun ◽  
Si-Hong Lee ◽  
...  

2009 ◽  
Vol 1217 ◽  
Author(s):  
Yoshitaka Nakano ◽  
Shu Saeki ◽  
Takeshi Morikawa

AbstractWe have investigated the effect of N doping into Cu2O films deposited by reactive magnetron sputtering. With increasing N-doping concentration up to 3 at.%, the optical bandgap energy is enlarged from ˜2.1 to ˜2.5 eV with retaining p-type conductivity as determined by optical absorption and Hall-effect measurements. Additionally, photoelectron spectroscopy in air measurements shows an increase in the valence and conduction band shifts with N doping. These experimental results demonstrate possible optical bandgap widening of p-type N-doped Cu2O films, which is a phenomenon that is probably associated with significant structural changes induced by N doping, as suggested from x-ray diffraction measurements.


2003 ◽  
Vol 42 (Part 2, No. 2B) ◽  
pp. L141-L143 ◽  
Author(s):  
Qixin Guo ◽  
Tooru Tanaka ◽  
Mitsuhiro Nishio ◽  
Hiroshi Ogawa

Author(s):  
Ahmad Alsaad ◽  
Ahmad Ahmad ◽  
Abdul Raouf Al Dairy ◽  
Issam A. Qattan ◽  
Shatha Al Fawares ◽  
...  

We report the synthesis and characterization of Poly Methyl-Meth-Acrylate (PMMA)/Poly vinylalcohol (PVA) polymeric blend doped with different concentrations of Copper oxide (CuO) nanoparticles (NPs). The (PMMA-PVA)/CuO nanocomposite hybrid thin films (wt. % = 0%, 2%, 4%, 8%, and 16%) of CuO NPs are deposited on glass substrates via dip-coating technique. The transmittance (T%), reflectance (R%), the absorption coefficient (α), the optical constants [refractive index (n), extinction coefficient (k)], optical dielectric functions [ɛ',ɛ''] are investigated and interpreted. Tauc, Urbach, Spitzer-Fan, and Drude models are employed to calculate the optical bandgap energy (Eg) and the optoelectronic parameters of the nanocomposite thin films. The refractive index and optical bandgap energy of of (PMMA-PVA) polymeric thin film are found to be (1.5 to 1.85) and 4.101 eV, respectively. Incorporation of specific concentrations of CuO-NPs in (PMMA-PVA) polymeric thin films leads to a noticeable decrease in the optical bandgap energy and to an increase of the refractive index. Moreover, Fourier Transform Infrared Spectroscopy (FTIR) transmittance spectra are measured and analyzed for undoped and doped polymeric thin films to pinpoint the major vibrational modes in the spectral range (500 and 4000 cm-1), as well as, the nature of network bonding in both systems. Thermal stability of thin films is investigated by performing thermogravimetric analysis (TGA). The TGA thermograms confirm that both doped polymeric thin films are thermally stable at temperatures below 110°C which enables them to be attractive for a wide range of optical and optoelectronic applications. Our results indicate that optical, vibrational and thermal properties of both polymeric thin films can be tuned for specific applications by the appropriate corporation of particular concentrations of CuO-NPs.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Susheel Arora ◽  
Virender Kundu ◽  
D. R. Goyal ◽  
A. S. Maan

The Melt-quench method is used to synthesize zinc fluoroborate glasses with compositions xZnO·(40−x)LiF·60B2O3 (x=0, 5, 10, 15, and 20). Optical characterization was carried out to examine the variation of optical bandgap energy (Eg) and urbach energy (EU) with respect to the concentration for the samples annealed at different temperatures (300°C, 350°C, and 400°C). Annealing shows its effect on the samples with the variations in the values of Eg and EU. These variations are explained on the basis of formation of different molecular species like BO3- units, boroxol rings, and the change in the number of nonbridging oxygen atoms.


2018 ◽  
Vol 61 (6) ◽  
pp. 886-892 ◽  
Author(s):  
Wei Huang ◽  
Yu Liu ◽  
ShiZhong Yue ◽  
LaiPan Zhu ◽  
Peng Jin ◽  
...  

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