Band gap determination using absorption spectrum fitting procedure

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Nader Ghobadi
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ateyyah M. Al-Baradi ◽  
Ahmed A. Atta ◽  
Ali Badawi ◽  
Saud A. Algarni ◽  
Abdulraheem S. A. Almalki ◽  
...  

Abstract In the current work, the optical properties of tin oxide thin films have been tailored via gamma irradiation for energy applications. The effect of Gamma radiation (50, 100, 150, 200 and 250 kGy) on the microstructural, absorption and oscillator parameters of SnO2 thin films has been investigated. XRD results reveal that the SnO2 films have the symmetry of the space group P42/mnm belonging to the tetragonal system. The crystallite size of γ-irradiated SnO2 thin film slightly increases as the irradiation dose increases. The allowed optical band gaps are estimated by applying various methods such as Tauc’s method, derivation of absorption spectrum fitting and absorption spectrum fitting approaches. The dispersion parameters are extracted from the dispersion curve of the real part of the refractive index. The single-effective-oscillator and Drude models for free charge carrier absorption are applied to obtain the dispersion parameters before and after γ-irradiation.


Author(s):  
Julia Wiktor ◽  
Igor Reshetnyak ◽  
Francesco Ambrosio ◽  
Alfredo Pasquarello

ChemInform ◽  
2014 ◽  
Vol 45 (40) ◽  
pp. no-no
Author(s):  
Feng Hao ◽  
Constantinos C. Stoumpos ◽  
Robert P. H. Chang ◽  
Mercouri G. Kanatzidis

2020 ◽  
Vol 34 (17) ◽  
pp. 2050147
Author(s):  
Yuqin Guan ◽  
Qingyu Hou ◽  
Danyang Xia

The effect of intrinsic point defects on the electronic structure and absorption spectra of ZnO was investigated by first-principle calculation. Among the intrinsic point defects in ZnO, oxygen vacancies [Formula: see text] and interstitial zinc [Formula: see text] have the lower formation energy and the more stable structure under zinc(Zn)-rich condition, whereas zinc vacancies [Formula: see text] and interstitial oxygen [Formula: see text] have the lower formation energy and the more stable structure under oxygen(O)-rich condition. The band gap of [Formula: see text] becomes narrow and the absorption spectrum has a redshift. In the visible region, the photo-excited electron transition of [Formula: see text] is graded from the valence band top to the impurity level and then to the conduction band bottom, showing the redshift of absorption spectrum of [Formula: see text] and explaining the reason of [Formula: see text] forming a deep impurity levels in ZnO. Moreover, the impurity energy level of [Formula: see text] coincides with the Fermi level, indicating the significant trap effect and the slow recombination of electrons and holes, which are conducive to the design and preparation of novel ZnO photocatalysts. The band gap of [Formula: see text] and [Formula: see text] broadened and the absorption spectrum showed blueshift, explaining the different values of the ZnO band gap width.


2020 ◽  
Vol 22 (21) ◽  
pp. 11936-11942
Author(s):  
Kangli Wang ◽  
Beate Paulus

Using the DFT-GW-BSE method, we analyze how the electronic band gap, optical absorption spectrum and exciton binding energy of the MoS2 monolayer are influenced by NO and C3H3N3 molecules and S-defects.


2014 ◽  
Vol 136 (22) ◽  
pp. 8094-8099 ◽  
Author(s):  
Feng Hao ◽  
Constantinos C. Stoumpos ◽  
Robert P. H. Chang ◽  
Mercouri G. Kanatzidis

2010 ◽  
Vol 177 ◽  
pp. 194-196
Author(s):  
Yong Qin Liu ◽  
Zhao Quan Gong ◽  
Li Ma ◽  
Dong Fang Xu ◽  
Da Zhi Sun

(Na0.535K0.48) NbO3 ceramics doped with Bi2O3•Fe2O3 are prepared by a ceramic process. The effect of Bi3+ and Fe3+ on microstructure and electrical properties of ceramics is investigated. X-ray diffraction shows that the structure of the material is perovskite. The conductivity of ceramics increases with the doping content. UV-Visual absorption spectrum is affected by doping Bi3+ and Fe3+. The mechanism of conductivity is discussed with respect to energy of band-gap in the system.


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