Phase change and optical band gap behavior of Ge-Zn-Te chalcogenide films

Author(s):  
Guoxiang Wang ◽  
Qiuhua Nie ◽  
Xiang Shen ◽  
Tiefeng Xu ◽  
Shixun Dai
2019 ◽  
pp. 14-25
Author(s):  
P. I. Lazarenko ◽  
◽  
Yu. V. Vorobyov ◽  
M. E. Fedyanina ◽  
A. A. Sherchenkov ◽  
...  

2020 ◽  
Vol 11 (2) ◽  
pp. 330-337 ◽  
Author(s):  
P. I. Lazarenko ◽  
Yu. V. Vorobyov ◽  
M. E. Fedyanina ◽  
A. A. Sherchenkov ◽  
S. A. Kozyukhin ◽  
...  

Vacuum ◽  
2012 ◽  
Vol 86 (10) ◽  
pp. 1572-1575 ◽  
Author(s):  
Guoxiang Wang ◽  
Qiuhua Nie ◽  
Xiang Shen ◽  
Fen Chen ◽  
Jun Li ◽  
...  

Solar Energy ◽  
2009 ◽  
Vol 83 (4) ◽  
pp. 522-526 ◽  
Author(s):  
N. Muthukumarasamy ◽  
S. Jayakumar ◽  
M.D. Kannan ◽  
R. Balasundaraprabhu

2015 ◽  
Vol 7 (3) ◽  
pp. 1923-1930
Author(s):  
Austine Amukayia Mulama ◽  
Julius Mwakondo Mwabora ◽  
Andrew Odhiambo Oduor ◽  
Cosmas Mulwa Muiva ◽  
Boniface Muthoka ◽  
...  

 Selenium-based chalcogenides are useful in telecommunication devices like infrared optics and threshold switching devices. The investigated system of Ge5Se95-xZnx (0.0 ≤ x ≤ 4 at.%) has been prepared from high purity constituent elements. Thin films from the bulk material were deposited by vacuum thermal evaporation. Optical absorbance measurements have been performed on the as-deposited thin films using transmission spectra. The allowed optical transition was found to be indirect and the corresponding band gap energy determined. The variation of optical band gap energy with the average coordination number has also been investigated based on the chemical bonding between the constituents and the rigidity behaviour of the system’s network.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1118
Author(s):  
Ibrahim Mustapha Alibe ◽  
Khamirul Amin Matori ◽  
Mohd Hafiz Mohd Zaid ◽  
Salisu Nasir ◽  
Ali Mustapha Alibe ◽  
...  

The contemporary market needs for enhanced solid–state lighting devices has led to an increased demand for the production of willemite based phosphors using low-cost techniques. In this study, Ce3+ doped willemite nanoparticles were fabricated using polymer thermal treatment method. The special effects of the calcination temperatures and the dopant concentration on the structural and optical properties of the material were thoroughly studied. The XRD analysis of the samples treated at 900 °C revealed the development and or materialization of the willemite phase. The increase in the dopant concentration causes an expansion of the lattice owing to the replacement of larger Ce3+ ions for smaller Zn2+ ions. Based on the FESEM and TEM micrographs, the nanoparticles size increases with the increase in the cerium ions. The mean particles sizes were estimated to be 23.61 nm at 1 mol% to 34.02 nm at 5 mol% of the cerium dopant. The optical band gap energy of the doped samples formed at 900 °C decreased precisely by 0.21 eV (i.e., 5.21 to 5.00 eV). The PL analysis of the doped samples exhibits a strong emission at 400 nm which is ascribed to the transition of an electron from localized Ce2f state to the valence band of O2p. The energy level of the Ce3+ ions affects the willemite crystal lattice, thus causing a decrease in the intensity of the green emission at 530 nm and the blue emission at 485 nm. The wide optical band gap energy of the willemite produced is expected to pave the way for exciting innovations in solid–state lighting applications.


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