scholarly journals Effects of Calcination Holding Time on Properties of Wide Band Gap Willemite Semiconductor Nanoparticles by the Polymer Thermal Treatment Method

Molecules ◽  
2018 ◽  
Vol 23 (4) ◽  
pp. 873 ◽  
Author(s):  
Ibrahim Alibe ◽  
Khamirul Matori ◽  
Hj Sidek ◽  
Yazid Yaakob ◽  
Umer Rashid ◽  
...  
2017 ◽  
Vol 73 ◽  
pp. 665-669 ◽  
Author(s):  
Isam M. Ibrahim ◽  
Iftikhar M. Ali ◽  
Batol Imran Dheeb ◽  
Qayes A. Abas ◽  
Asmeit Ramizy ◽  
...  

Author(s):  
Joanna L. Batstone

Interest in II-VI semiconductors centres around optoelectronic device applications. The wide band gap II-VI semiconductors such as ZnS, ZnSe and ZnTe have been used in lasers and electroluminescent displays yielding room temperature blue luminescence. The narrow gap II-VI semiconductors such as CdTe and HgxCd1-x Te are currently used for infrared detectors, where the band gap can be varied continuously by changing the alloy composition x.Two major sources of precipitation can be identified in II-VI materials; (i) dopant introduction leading to local variations in concentration and subsequent precipitation and (ii) Te precipitation in ZnTe, CdTe and HgCdTe due to native point defects which arise from problems associated with stoichiometry control during crystal growth. Precipitation is observed in both bulk crystal growth and epitaxial growth and is frequently associated with segregation and precipitation at dislocations and grain boundaries. Precipitation has been observed using transmission electron microscopy (TEM) which is sensitive to local strain fields around inclusions.


Author(s):  
Raquel Caballero ◽  
Leonor de la Cueva ◽  
Andrea Ruiz-Perona ◽  
Yudenia Sánchez ◽  
Markus Neuschitzer ◽  
...  

2013 ◽  
Vol 28 (6) ◽  
pp. 671-676 ◽  
Author(s):  
Yu-Qing ZHANG ◽  
Li-Li ZHAO ◽  
Shi-Long XU ◽  
Chao ZHANG ◽  
Xiao-Ying CHEN ◽  
...  

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 115
Author(s):  
Suhail Huzaifa Jaafar ◽  
Mohd Hafiz Mohd Zaid ◽  
Khamirul Amin Matori ◽  
Sidek Hj. Ab Aziz ◽  
Halimah Mohamed Kamari ◽  
...  

This research paper proposes the usage of a simple thermal treatment method to synthesis the pure and Eu3+ doped ZnO/Zn2SiO4 based composites which undergo calcination process at different temperatures. The effect of calcination temperatures on the structural, morphological, and optical properties of ZnO/Zn2SiO4 based composites have been studied. The XRD analysis shows the existence of two major phases which are ZnO and Zn2SiO4 crystals and supported by the finding in the FT-IR. The FESEM micrograph further confirms the existence of both ZnO and Zn2SiO4 crystal phases, with progress in the calcination temperature around 700–800 °C which affects the existence of the necking-like shape particle. Absorption humps discovered through UV-Vis spectroscopy revealed that at the higher calcination temperature effects for higher absorption intensity while absorption bands can be seen at below 400 nm with dropping of absorption bands at 370–375 nm. Two types of band gap can be seen from the energy band gap analysis which occurs from ZnO crystal and Zn2SiO4 crystal progress. It is also discovered that for Eu3+ doped ZnO/Zn2SiO4 composites, the Zn2SiO4 crystal (5.11–4.71 eV) has a higher band gap compared to the ZnO crystal (3.271–4.07 eV). While, for the photoluminescence study, excited at 400 nm, the emission spectra of Eu3+ doped ZnO/Zn2SiO4 revealed higher emission intensity compared to pure ZnO/Zn2SiO4 with higher calcination temperature exhibit higher emission intensity at 615 nm with 700 °C being the optimum temperature. The emission spectra also show that the calcination temperature contributed to enhancing the emission intensity.


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