Cl Doping Effect by Thermal Treatment with KCl for ZnO Single Crystals

2011 ◽  
Vol 1288 ◽  
Author(s):  
Akira Fujimoto ◽  
Yoshiyuki Harada

ABSTRACTWe investigated the optical and electrical properties of ZnO single crystals coated with KCl by examining the photoluminescence (PL) at 9 K and the temperature dependence of the carrier concentration. The band-edge PL intensity of the KCl-coated sample was much larger than that of the uncoated sample. Moreover, a substantial increase in Hall electrons was observed in the coated sample. X-ray photoelectron spectroscopy revealed bonding between chlorine and zinc atoms in the coated sample. Therefore, coating the surface of ZnO single crystals with KCl enhances the donor concentration and improves the surface state.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yerassyl Yerlanuly ◽  
Rakhymzhan Zhumadilov ◽  
Renata Nemkayeva ◽  
Berik Uzakbaiuly ◽  
Almaz R. Beisenbayev ◽  
...  

AbstractInvestigation of the physical properties of carbon nanowall (CNW) films is carried out in correlation with the growth time. The structural, electronic, optical and electrical properties of CNW films are investigated using electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, UV–Vis spectroscopy, Hall Effect measurement system, Four Point Probing system, and thermoelectric measurements. Shorter growth time results in thinner CNW films with a densely spaced labyrinth structure, while a longer growth time results in thicker CNW films with a petal structure. These changes in morphology further lead to changes in the structural, optical, and electrical properties of the CNW.


2021 ◽  
Vol 03 (03) ◽  
pp. 1-1
Author(s):  
Ganga R. Neupane ◽  
◽  
Amrit Kaphle ◽  
David N. Mcllroy ◽  
Elena Echeverria ◽  
...  

Iron doped ZnO (Fe-ZnO) nanoparticles were synthesized using two techniques that are economical as well as scalable to yield tunable properties of nanoparticles for facilitating down conversion in an absorbing layer of a solar cell. To evaluate the suitability of Fe-ZnO nanoparticles prepared by two deposition methods, we present a comparison of optical, electrical, and structural properties of Fe-ZnO using several experimental techniques. Structural properties were analyzed using transmission electron microscopy and x-ray diffraction spectroscopy (XRD) with Rietveld analysis for extracting information on compositional variations with Fe doping. The chemical composition of nanoparticles was analyzed through X-ray photoelectron spectroscopy (XPS). The optical properties of nanoparticles were studied using photoluminescence and UV-Vis absorption spectroscopy. In addition, fluorescence lifetime measurement was also performed to study the changes in an exponential decay of lifetimes. The electrical transport properties of Fe-ZnO were analyzed by impedance spectroscopy. Our studies indicate that ethanol as a solvent in a microwave method would produce smaller nanoparticles up to the size of 11 nm. In contrast, the precipitation method produces secondary phases of Fe2O3 beyond 5% doping. In addition, our studies show that the optical and electrical properties of resulting Fe-ZnO nanoparticles depend on the particle sizes and the synthesis techniques used. These new results provide insight into the role of solvents in fabricating Fe-ZnO nanoparticles by precipitation and microwave methods for photovoltaic and other applications.


Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1008 ◽  
Author(s):  
Hong-Ping Ma ◽  
Hong-Liang Lu ◽  
Jia-He Yang ◽  
Xiao-Xi Li ◽  
Tao Wang ◽  
...  

In this study, silicon nitride (SiNx) thin films with different oxygen concentration (i.e., SiON film) were precisely deposited by plasma enhanced atomic layer deposition on Si (100) substrates. Thus, the effect of oxygen concentration on film properties is able to be comparatively studied and various valuable results are obtained. In detail, x-ray reflectivity, x-ray photoelectron spectroscopy, atomic force microscopy, and spectroscopic ellipsometry are used to systematically characterize the microstructural, optical, and electrical properties of SiON film. The experimental results indicate that the surface roughness increases from 0.13 to 0.2 nm as the oxygen concentration decreases. The refractive index of the SiON film reveals an increase from 1.55 to 1.86 with decreasing oxygen concentration. Accordingly, the band-gap energy of these films determined by oxygen 1s-peak analysis decreases from 6.2 to 4.8 eV. Moreover, the I-V tests demonstrate that the film exhibits lower leakage current and better insulation for higher oxygen concentration in film. These results indicate that oxygen affects microstructural, optical, and electrical properties of the prepared SiNx film.


2010 ◽  
Vol 663-665 ◽  
pp. 413-416 ◽  
Author(s):  
Chen Yang ◽  
Zhi Ming Chen ◽  
Ying Xue Xi ◽  
Tao Lin

In this paper, thin HfO2 films were grown by using E-beam evaporation technique in vacuum and O2 ambient, respectively. Effects of O2 ambient on structural, optical and electrical properties of the HfO2 films were investigated by deploying x-ray photoelectron spectroscopy, ultraviolet visible spectroscopy, I-V and C-V characteristics. Results show that the O2 ambient deposited HfO2 films exhibited excellent structural, optical and electrical properties as compared with vacuum ambient HfO2 films, which especially performs a low content of metal Hf, a high transmittance, a low leakage current and a high dielectric constant.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.


2019 ◽  

Transparent conducting oxide (TCO) thin films are materials of significance for their applications in optoelectronics and sun powered cells. Fluorine-doped tin oxide (FTO) is an elective material in the advancement of TCO films. This paper reports the impact of fluorine doping on structural, optical and electrical properties of tin oxide thin films for solar cells application. The sol-gel was prepared from anhydrous stannous chloride, SnCl2 as an originator, 2-methoxyethanol as a solvent, di-ethanolamine as a preservative and ammonium fluoride as the dopant source. FTO precursor solution was formulated to obtain 0, 5, 10, 15 and 20 % doping concentration and deposited on glass substrates by means of spin coater at the rate of 2000 rpm for 40 seconds. After pre-heated at 200 oC, the samples were annealed at 600 oC for 2 h. The structural, optical and electrical characteristics of prepared films were characterized using X-ray diffraction (XRD) analysis, UV-visible spectroscopy and electrical measurement. X-ray diffraction (XRD) investigation of the films demonstrated that the films were polycrystalline in nature with tetragonal-cassiterite structure with most extraordinary pinnacle having a grain size of 17.01 nm. Doping with fluorine decreases the crystallite size. There was increment in the absorbance of the film with increasing wavelength and the transmittance was basically reduced with increasing fluorine doping in the visible region. The energy band gaps were in the range of 4.106-4.121 eV. The sheet resistance were observed to decrease as the doping percentage of fluorine increased with exception at higher doping of 15 and 20 %. In view of these outcomes, FTO thin films prepared could have useful application in transparent conducting oxide electrode in solar cell.


1997 ◽  
Vol 12 (9) ◽  
pp. 2388-2392 ◽  
Author(s):  
C. Miot ◽  
E. Husson ◽  
C. Proust ◽  
R. Erre ◽  
J. P. Coutures

Powder and ceramics of barium titanate prepared by the citric process were studied by x-ray photoelectron spectroscopy (XPS). Spectra of C1s, O1s, Ti2p, Ba3d, and Ba4d levels are analyzed in powder and ceramics immediately after the sintering step and after several months of exposure in the air. Ar-ion etching allowed one to characterize the material intrinsic carbon. The results are discussed in comparison with works previously published on oxide single crystals.


2019 ◽  
Vol 33 (23) ◽  
pp. 1950274
Author(s):  
Ying Liu ◽  
Dapeng Xu ◽  
Huamin Yu ◽  
Tian Cui ◽  
Liang Li

The columbite structure [Formula: see text] single crystals have been successfully grown by using the optical floating zone method. The as-grown crystals are characterized by X-ray diffraction (XRD), Raman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS). All these analyses show that the doping Co ions do not disturb the structure of columbite [Formula: see text] and some [Formula: see text] ions are substituted by transition metal [Formula: see text] ions without any other impurities. The magnetic properties of as-grown [Formula: see text] crystals have been investigated using Physical Property Measurement System (PPMS). The effective magnetic moment of [Formula: see text] crystals is [Formula: see text], indicating that [Formula: see text] ions present in [Formula: see text] single crystals are in mixed HS and LS states. The ferromagnetic, antiferromagnetic and paramagnetic characters of as-grown crystals are also discussed.


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