Non-parabolicity and band gap re-normalisation in Si doped ZnO

2014 ◽  
Vol 115 (6) ◽  
pp. 063505 ◽  
Author(s):  
R. E. Treharne ◽  
L. J. Phillips ◽  
K. Durose ◽  
A. Weerakkody ◽  
I. Z. Mitrovic ◽  
...  
Keyword(s):  
Band Gap ◽  
Si Doped ◽  
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.


1999 ◽  
Vol 74 (1) ◽  
pp. 102-104 ◽  
Author(s):  
In-Hwan Lee ◽  
J. J. Lee ◽  
P. Kung ◽  
F. J. Sanchez ◽  
M. Razeghi

Plasmonics ◽  
2021 ◽  
Author(s):  
Soumya Kannoth ◽  
Packia Selvam Irulappan ◽  
Sandip Dhara ◽  
Sankara Narayanan Potty

2015 ◽  
Vol 161 ◽  
pp. 275-280 ◽  
Author(s):  
Mohd. Arshad ◽  
Mohd. Meenhaz Ansari ◽  
Arham S. Ahmed ◽  
Pushpendra Tripathi ◽  
S.S.Z. Ashraf ◽  
...  

2017 ◽  
Vol 4 (9) ◽  
pp. 096404 ◽  
Author(s):  
Reza Mohammadigharehbagh ◽  
Soner Özen ◽  
Hafizittin Hakan Yudar ◽  
Suat Pat ◽  
Şadan Korkmaz

RSC Advances ◽  
2017 ◽  
Vol 7 (61) ◽  
pp. 38757-38764 ◽  
Author(s):  
Shuai He ◽  
Aize Hao ◽  
Ni Qin ◽  
Dinghua Bao

The resistive switching performance of ZnO thin films can be enhanced by decreasing the band gap and controlling oxygen vacancies.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Maria E. Manríquez ◽  
Luis Enrique Noreña ◽  
Jin An Wang ◽  
Lifang Chen ◽  
Jose Salmones ◽  
...  

The photocatalytic degradation of 4-chlorophenol in water using Ru-doped ZnO mixed oxides (0, 0.5, 1, and 3 wt% RuO2) synthesized by the one-pot homogeneous coprecipitation method is reported. ZnO with wurtzite structure was present in the mixed oxide as corroborated by Raman spectroscopy and X-ray diffraction analysis. All the samples showed nanorod morphological features. The presence of Ru6+/Ru4+ couples on ZnO modified the band gap of the mixed oxides and led to a shift of the band gap energy from 3.20 eV to 3.07 eV. Ru addition increased the surface area and significantly promoted the formation of active surface oxygen species such as hydroradicals evidenced by the fluorescence spectroscopy measurement. In the photodegradation of 4-chlorophenol solution under UV irradiation, a notable increase in photoactivity was obtained as the amount of RuO2 in the mixed oxides increased to 3 wt%. The charge transfer between Ru6+/Ru4+ couples and ZnO nanoparticles together with the formation of free radical oxidant species effectively inhibits electron-hole recombination rate, thus favoring the photodegradation of 4-chlorophenol.


2021 ◽  
Author(s):  
Mohamed Achehboune ◽  
Mohammed Khenfouch ◽  
Issam Boukhoubza ◽  
Issam Derkaoui ◽  
Bakang Moses Mothudi ◽  
...  

Abstract Density functional theory-based investigation of the electronic, magnetic, and optical characteristics in pure and ytterbium (Yb) doped ZnO has been carried out by the plane-wave pseudopotential technique with generalized gradient approximation. The calculated lattice parameters and band gap of pure ZnO are in good agreement with the experimental results. The energy band-gap increases with the increase of Yb concentration. The Fermi level moves upward into the conduction band after doping with Yb, which shows the properties of an n-type se miconductor. New defects were created in the band-gap near the conduction band attributed to the Yb-4f states. The magnetic properties of ZnO were found to be affected by Yb doping; ferromagnetic property was observed for 4.17% Yb due to spin polarization of Yb-4f electrons. The calculated optical properties imply that Yb doped causes a blue shift of the absorption peaks, significantly enhances the absorption of the visible light, and the blue shift of the reflectivity spectrum was observed. Besides, a better transmittance of approximately 88% was observed for 4.17% Yb doped ZnO system. The refractive index and the extinction coefficient were observed to decrease as the Yb dopant concentration increased. As a result, we believe that our findings will be useful in understanding the doping impact in ZnO and will motivate further theoretical research.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Xian-Yang Feng ◽  
Zhe Wang ◽  
Chang-Wen Zhang ◽  
Pei-Ji Wang

The electronic and magnetic properties of IIIA group doped ZnO nanosheets (ZnONSs) are investigated by the first principles. The results show that the band gap of ZnO nanosheets increases gradually along with Al, Ga, and In ions occupying Zn sites and O sites. The configuration of Al atoms replacing Zn atoms is more stable than other doped. The system shows half-metallic characteristics for In-doped ZnO nanosheets.


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