Structural, Optical and Electrical Properties of μc-Si:H Very Thin Films Deposited by the VHF-GD Technique

1994 ◽  
Vol 336 ◽  
Author(s):  
Roger Flückiger ◽  
J. Meier ◽  
A. Shah ◽  
A. Catana ◽  
M. Brunel ◽  
...  

ABSTRACTIn this paper we present new results for very thin <p> μc-Si:H films (< 350 Å) deposited at low temperature (170 C) by the Very High Frequency - Glow Discharge technique (VHF-GD) at 70 MHz. First, the effect of boron doping on the growth and electrical properties of μc-Si:H very thin films is investigated, leading to an optimised value of about 0.6 % (B2H6/SiH4). Structural properties of an optimised thickness series ranging from 100 to 350 Å are studied using TEM, Raman, grazing angle X-ray diffraction/reflection and spectroscopie ellipsometry. Further, a columnar structure growth model for these very thin <p>-type μc-Si:H films will be proposed.

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3360
Author(s):  
Yakir Dahan ◽  
Eldad Holdengreber ◽  
Elichai Glassner ◽  
Oz Sorkin ◽  
Shmuel E. Schacham ◽  
...  

A new measurement technique of electrical parameters of superconducting thin films at the Very High Frequency (VHF) range is described, based on resonators with microstrip (MS) structures. The design of an optimal resonator was achieved, based on a thorough theoretical analysis, which is required for derivation of the exact configuration of the MS. A theoretical model is presented, from which an expression for the attenuation of a MS line can be derived. Accordingly, simulations were performed, and an optimal resonator for the VHF range was designed and implemented. Production constraints of YBa2Cu3O7 (YBCO) limited the diameter of the sapphire substrate to 3″. Therefore, a meander configuration was formed to fit the long λ/4 MS line on the wafer. By measuring the complex input reflection coefficients of a λ/4 resonator, we extracted the quality factor, which is mainly affected by the dielectric and conductor attenuations. The experimental results are well fitted by the theoretical model. The dielectric attenuation was calculated using the quasi-static analysis of the MS line. An identical copper resonator was produced and measured to compare the properties of the YBCO resonator in reference to the copper one. A quality factor of ~6·105 was calculated for the YBCO resonator, three orders of magnitude larger than that of the copper resonator. The attenuation per unit length of the YBCO layer was smaller by more than five orders of magnitude than that of the copper.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4017
Author(s):  
Dorota Szwagierczak ◽  
Beata Synkiewicz-Musialska ◽  
Jan Kulawik ◽  
Norbert Pałka

New ceramic materials based on two copper borates, CuB2O4 and Cu3B2O6, were prepared via solid state synthesis and sintering, and characterized as promising candidates for low dielectric permittivity substrates for very high frequency circuits. The sintering behavior, composition, microstructure, and dielectric properties of the ceramics were investigated using a heating microscope, X-ray diffractometry, scanning electron microscopy, energy dispersive spectroscopy, and terahertz time domain spectroscopy. The studies revealed a low dielectric permittivity of 5.1–6.7 and low dielectric loss in the frequency range 0.14–0.7 THz. The copper borate-based materials, owing to a low sintering temperature of 900–960 °C, are suitable for LTCC (low temperature cofired ceramics) applications.


1988 ◽  
Vol 66 (5) ◽  
pp. 373-375 ◽  
Author(s):  
C. J. Arsenault ◽  
D. E. Brodie

Zn-rich and P-rich amorphous Zn3P2 thin films were prepared by co-evaporation of the excess element during the normal Zn3P2 deposition. X-ray diffraction techniques were used to investigate the structural properties and the crystallization process. Agglomeration of the excess element within the as-made amorphous Zn3P2 thin film accounted for the structural properties observed after annealing the sample. Electrical measurements showed that excess Zn reduces the conductivity activation energy and increases the conductivity, while excess P up to 15 at.% does not alter the electrical properties significantly.


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.


2016 ◽  
Vol 120 (10) ◽  
pp. 104101 ◽  
Author(s):  
N. Vaxelaire ◽  
V. Kovacova ◽  
A. Bernasconi ◽  
G. Le Rhun ◽  
M. Alvarez-Murga ◽  
...  

2011 ◽  
Vol 383-390 ◽  
pp. 822-825
Author(s):  
Ping Luan ◽  
Jian Sheng Xie ◽  
Jin Hua Li

Using magnetron sputtering technology, the CuInSi thin films were prepared by multilayer synthesized method. The structure of CuInSi films were detected by X-ray diffraction(XRD), the main crystal phase peak is at 2θ=42.458°; The resistivity of films were measured by SDY-4 four-probe meter; The conductive type of the films were tested by DLY-2 conductivity type testing instrument. The results show that the annealing temperature and time effect on the crystal resistivity and crystal structure greatly.


2001 ◽  
Vol 666 ◽  
Author(s):  
Fumiaki Mitsugi ◽  
Tomoaki Ikegami ◽  
Kenji Ebihara ◽  
Jagdish Narayan ◽  
Alexander M. Grishin

ABSTRACTWe prepared colossal magnetoresistive La0.8Sr0.2MnO3 thin films on the MgO, SrTiO3 and LaAlO3 single crystal substrates using KrF excimer pulsed laser ablation technique. The structural and electrical properties of the La0.8Sr0.2MnO3 thin films which were strained by the lattice mismatch are reported. The in-plane lattice mismatch between the La0.8Sr0.2MnO3 and MgO, SrTiO3 and LaAlO3 substrates are -7.8 %, -0.5 % and +2.3 %, respectively. The X-ray diffraction spectra of the films exhibited c-axis orientation. In the case of the La0.8Sr0.2MnO3 / LaAlO3 thin films with thickness over 100 nm, the divided (00l) peaks were observed. The surface morphology and transport property of the strongly stressed La0.8Sr0.2MnO3 / LaAlO3 were different from those of La0.8Sr0.2MnO3 / MgO and La0.8Sr0.2MnO3 / SrTiO3thin films.


2008 ◽  
Vol 93 (19) ◽  
pp. 191502 ◽  
Author(s):  
C. Jariwala ◽  
A. Chainani ◽  
R. Eguchi ◽  
M. Matsunami ◽  
S. Shin ◽  
...  

2005 ◽  
Vol 19 (01n03) ◽  
pp. 671-673
Author(s):  
PENG XIAO ◽  
WANLU WANG

The Fe 3+- TiO 2 thin films obtained through sol-gel method were characterized by x-ray diffraction, AFM and Raman spectroscopy. It was found that TiO 2 films consisted of nanometer particles. The experimental results shows that the nanometer TiO 2 thin films doped with Fe 3+ were greatly improved in the activity aspect. This may be ascribed to change their structure and electrical properties after doping with Fe 3+. The results were discussed theoretically in detail.


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