Explaining doping in material research (Hf substitution in ZnO films) by directly quantifying the van der Waals force

2020 ◽  
Vol 22 (7) ◽  
pp. 4130-4137
Author(s):  
Chia-Yun Lai ◽  
Sergio Santos ◽  
Toni Moser ◽  
Boulos Alfakes ◽  
Jin-You Lu ◽  
...  

Non-monotonic behavior has been observed in the optoelectronic properties of ZnO thin films as doped with Hf (HZO).

2014 ◽  
Vol 881-883 ◽  
pp. 1117-1121 ◽  
Author(s):  
Xiang Min Zhao

ZnO thin films with different thickness (the sputtering time of AlN buffer layers was 0 min, 30 min,60 min, and 90 min, respectively) were prepared on Si substrates using radio frequency (RF) magnetron sputtering system.X-ray diffraction (XRD), atomic force microscope (AFM), Hall measurements setup (Hall) were used to analyze the structure, morphology and electrical properties of ZnO films.The results show that growth are still preferred (002) orientation of ZnO thin films with different sputtering time of AlN buffer layer,and for the better growth of ZnO films, the optimal sputtering time is 60 min.


2016 ◽  
Vol 680 ◽  
pp. 124-128 ◽  
Author(s):  
Chao Du ◽  
Yu Chun Zou ◽  
Zhi Qing Chen ◽  
Wen Kui Li ◽  
Shan Shan Luo

ZnO thin films have attractive applications in photoelectric device, due to their excellent chemical, electrical and optical properties. In this paper, ZnO thin films with good c-axis preferred orientation and high transmittance are prepared on glass sheets by sol-gel immerse technique. The effects of withdrawal speeds on the growth process of thin film crystal, film crystal orientation and the crystallinity, the optical performance were investigated by XRD, SEM and UV-Vis spectrophotometry. The results show that the thin films were composed of better hexagonal wurtzite crystals with the c-axis prepared orientation. The transmittance of prepared thin films is over 80% in the visible-near IR region from 600 nm - 800 nm. ZnO films have sharp and narrow diffraction peaks, which indicates that the materials exhibit high crystallinity. With the withdrawal speeds increasing, the grain size of ZnO thin films and the intensity for all diffraction peaks were increased gradually. The growth model is changed from the stratified structure into the island structure in the growth process. The transmittance of the thin films decrease in the visible wavelength region, with the withdrawal speeds increasing.


2006 ◽  
Vol 510-511 ◽  
pp. 670-673 ◽  
Author(s):  
Chong Mu Lee ◽  
Yeon Kyu Park ◽  
Anna Park ◽  
Choong Mo Kim

This paper investigated the effects of annealing atmosphere on the carrier concentration, carrier mobility, electrical resistivity, and PL characteristics as well as the crystallinity of ZnO films deposited on sapphire substrates by atomic layer deposition (ALD). X-ray diffraction (XRD) and photoluminescence (PL) analyses, and Hall measurement were performed to investigate the crystallinity, optical properties and electrical properties of the ZnO thin films, respectively. According to the XRD analysis results, the crystallinity of the ZnO film annealed in an oxygen atmosphere is better than that of the ZnO film annealed in a nitrogen atmosphere. It was found that annealing undoped ZnO films grown by ALD at a high temperature above 600°C improves the crystallinity and enhances UV emission.


Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 252 ◽  
Author(s):  
A. M. Alsaad ◽  
A. A. Ahmad ◽  
I. A. Qattan ◽  
Qais M. Al-Bataineh ◽  
Zaid Albataineh

Undoped ZnO and group III (B, Al, Ga, and In)-doped ZnO thin films at 3% doping concentration level are dip-coated on glass substrates using a sol-gel technique. The optical properties of the as-prepared thin films are investigated using UV–Vis spectrophotometer measurements. Transmittance of all investigated thin films is found to attain high values of ≥80% in the visible region. We found that the index of refraction of undoped ZnO films exhibits values ranging between 1.6 and 2.2 and approximately match that of bulk ZnO. Furthermore, we measure and interpret nonlinear optical parameters and the electrical and optical conductivities of the investigated thin films to obtain a deeper insight from fundamental and practical points of view. In addition, the structural properties of all studied thin film samples are investigated using the XRD technique. In particular, undoped ZnO thin film is found to exhibit a hexagonal structure. Due to the large difference in size of boron and indium compared with that of zinc, doping ZnO thin films with these two elements is expected to cause a phase transition. However, Al-doped ZnO and Ga-doped ZnO thin films preserve the hexagonal phase. Moreover, as boron and indium are introduced in ZnO thin films, the grain size increases. On the other hand, grain size is found to decrease upon doping ZnO with aluminum and gallium. The drastic enhancement of optical properties of annealed dip-synthesized undoped ZnO thin films upon doping with group III metals paves the way to tune these properties in a skillful manner, in order to be used as key candidate materials in the fabrication of modern optoelectronic devices.


Author(s):  
S. Venkatachalam ◽  
H. Nanjo ◽  
K. Kawasaki ◽  
H. Hayashi ◽  
T. Ebina ◽  
...  

2020 ◽  
Vol 22 (4) ◽  
pp. 2010-2018 ◽  
Author(s):  
Muhammad Abiyyu Kenichi Purbayanto ◽  
Andrivo Rusydi ◽  
Yudi Darma

The crystallinity of starting materials has a vital role in determining the structure modification and optical properties of ZnO films after H2 annealing.


2017 ◽  
Vol 214 (6) ◽  
pp. 1600941 ◽  
Author(s):  
Asad J. Mughal ◽  
Benjamin Carberry ◽  
Sang Ho Oh ◽  
Anisa Myzaferi ◽  
James S. Speck ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Manju Arora ◽  
Rayees A. Zargar ◽  
S. D. Khan

Nanocrystalline zinc oxide (nc-ZnO) thin films were grown on p-type silicon substrate through spin coating by sol-gel process using different sol concentrations (10 wt.%, 15 wt.%, and 25 wt.%). These films were characterized by high resolution nondestructive X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDS) attachment, and electron paramagnetic resonance (EPR) techniques to understand variations in structural, morphological, and oxygen vacancy with respect to sol concentration. The film surface morphology changes from nanowall to nanorods on increasing sol concentration. EPR spectra revealed the systematic variation from ferromagnetic to paramagnetic nature in these nc-ZnO films. The broad EPR resonance signal arising from the strong dipolar-dipolar interactions among impurity defects present in nc-ZnO film deposited from 10 wt.% sol has been observed and a single strong narrow resonance signal pertaining to oxygen vacancies is obtained in 25 wt.% sol derived nc-ZnO film. The concentrations of impurity defects and oxygen vacancies are evaluated from EPR spectra, necessary for efficient optoelectronic devices development.


2019 ◽  
Vol 125 (9) ◽  
Author(s):  
Ilyass Jellal ◽  
Hassan Ahmoum ◽  
Yassine Khaaissa ◽  
Khalid Nouneh ◽  
Mourad Boughrara ◽  
...  

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