TEM Examination on the Microstructure Rearrangement of ECRPVECD Nc-Si Thin Films Caused By Low Temperature Annealing

1999 ◽  
Vol 5 (S2) ◽  
pp. 844-845
Author(s):  
S.C. Cheng ◽  
A.K. Kalkan ◽  
S.H. Bae ◽  
S.J. Fonash

In an earlier report we have shown that the infrared photoluminescence (PL) from nanocrystalline Si films shifts to lower energies with increasing deposition temperature (in the range of 180-340 °C) and with thermal annealing. These films were deposited on Corning 1737 glass substrates using a Plasma-Therm SLR 770 ECR-PECVD system to a thickness of 4500 Å. The redshift of PL correlates well with the narrowing of (111) XRD peak, the redshift of the optical absoiption profile, the increasing conductivity and the decreasing activation energy for conductivity. Therefore, the energy shift of the PL has been considered as the result of variations in bandgap due to variations in crystallite size; i.e., variations in the quantum confinement. For the samples investigated, the PL band peak was found within the extrema of 0.99 to 0.81 eV (at 77 K). These extreme values correspond to the film deposited at 180 °C (0.99 eV PL) and the same film annealed at 600 °C for 72 hours (0.81 eV PL).

1981 ◽  
Vol 4 ◽  
Author(s):  
G. Auvert ◽  
D. Bensahel ◽  
A. Perio ◽  
F. Morin ◽  
G.A. Rozgonyi ◽  
...  

ABSTRACTExplosive Crystallization occurs in cw laser annealing on a-Si films deposited on glass substrates at laser scan speeds higher than 30 cm/sec. Optical, structural and electrical properties of the crystallized films at various laser scan speeds confirm the existence of two kinds of explosive growth depending on the state of crystallinity of the starting material.


Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1183
Author(s):  
Peiyu Wang ◽  
Xin Wang ◽  
Fengyin Tan ◽  
Ronghua Zhang

Molybdenum disulfide (MoS2) thin films were deposited at different temperatures (150 °C, 225 °C, 300 °C, 375 °C, and 450 °C) on quartz glass substrates and silicon substrates using the RF magnetron sputtering method. The influence of deposition temperature on the structural, optical, electrical properties and deposition rate of the obtained thin films was investigated by X-ray diffraction (XRD), Energy Dispersive Spectrometer (EDS), Raman, absorption and transmission spectroscopies, a resistivity-measuring instrument with the four-probe method, and a step profiler. It was found that the MoS2 thin films deposited at the temperatures of 150 °C, 225 °C, and 300 °C were of polycrystalline with a (101) preferred orientation. With increasing deposition temperatures from 150 °C to 300 °C, the crystallization quality of the MoS2 thin films was improved, the Raman vibrational modes were strengthened, the deposition rate decreased, and the optical transmission and bandgap increased. When the deposition temperature increased to above 375 °C, the molecular atoms were partially combined with oxygen atoms to form MoO3 thin film, which caused significant changes in the structural, optical, and electrical properties of the obtained thin films. Therefore, it was necessary to control the deposition temperature and reduce the contamination of oxygen atoms throughout the magnetron sputtering process.


2012 ◽  
Vol 186 ◽  
pp. 7-12 ◽  
Author(s):  
János L. Lábár ◽  
Ákos K. Kiss ◽  
Silke Christiansen ◽  
Fritz Falk

A method is presented here for complete geometrical characterization of grain boundaries, based on measurement of thin films in the TEM. First, the three parameters, characterizing the misorientation of the two neighboring grains are determined from convergent beam electron diffraction (CBED). Next, the last two (of the total five macroscopic degrees of freedom) parameters are determined from bright field (BF) images to describe the orientation of the boundary plane between them. Ambiguity in the tilt direction of the plane is resolved from BF images recorded at two distinct goniometer settings. Application of the method is demonstrated in Silicon thin films. GB-plane distribution in a thin film is not necessarily identical to the distribution of similar planes in bulk materials. It was observed in low dimensional fcc metals (wires or thin films) that energy minimization of GBs can follow two (mainly alternative) routes. Either low energy planes (like {111}) are formed in 3 boundaries, or alternatively, it is observed that the GB plane has a general index (and high energy density) but it ends at both free surfaces of the sample, resulting in a GB, almost normal to the sample surface, minimizing the total area of the GB. We observed that this later type of planes is mainly characteristic of non-3 boundaries in thin Si films, crystallized from melt on glass substrates (separated by a thin SiN barrier layer). This observation is important for the expected recombination properties of the multicrystalline Si (m-Si) in planned solar cell (SC) applications.


2012 ◽  
Vol 198-199 ◽  
pp. 28-31
Author(s):  
Chun Ya Li ◽  
Xi Feng Li ◽  
Long Long Chen ◽  
Ji Feng Shi ◽  
Jian Hua Zhang

Under different growth conditions, silicon Oxide (SiOx) thin films were deposited successfully on Si (100) substrates and glass substrates by plasma enhanced chemical vapor deposition (PECVD). The thickness, refractive index and growth rate of the thin films were tested by ellipsometer. The effects of deposition temperature on the structure and properties of SiOx films were studied using X ray diffraction (XRD), X ray photoelectron spectroscopy (XPS) and UV-Visible spectroscopy. The results show that the SiOx films were amorphous at different deposition temperature. The peaks of Si2p and O1s shifted to higher binding energy with temperature increasing. The SiOx films had high transmissivity at the range of 400-900nm. By analyzing the observation and data, the influence of deposition parameters on the electrical properties and interface characteristics of SiOx thin film prepared by PECVD is systematically discussed. At last, SiOx thin film with excellent electrical properties and good interface characteristic is prepared under the relatively optimum parameters.


1998 ◽  
Vol 517 ◽  
Author(s):  
Yoshiyasu Yamada ◽  
Takao Suzuki

AbstractThe very large perpendicular magnetic anisotropy of the order of 2 x 107 erg/cm3 at room temperature was found in CoJ-x Ptx(0<x<0.5) alloy thin films made by e-beam evaporation. The large magnetic anisotropy is likely related to the anisotropic Co-Co bonding distribution, which is similar to the cases of Co/Pt multilayers and FePt alloy thin films. The activation energy estimated for the ordering is approximately 0.3 eV, which is preferably compared to 0.2 eV for FePt. A model is proposed, for which both a short range and long range ordering are present, depending on substrate deposition temperature.


2017 ◽  
Vol 14 (4) ◽  
pp. 793-796
Author(s):  
Baghdad Science Journal

CdS films were prepared by thermal evaporation technique at thickness 1 µm on glass substrates and these films were doped with indium (3%) by thermal diffusion method. The electrical properties of these have been investigated in the range of diffusion temperature (473-623 K)> Activation energy is increased with diffusion temperature unless at 623 K activation energy had been decreased. Hall effect results have shown that all the films n-type except at 573 and 623 K and with increase diffusion temperature both of concentration and mobility carriers were increased.


2001 ◽  
Vol 685 ◽  
Author(s):  
Y.-G. Yoon ◽  
G.-B. Kim ◽  
H.-H Park ◽  
S.-W Lee ◽  
S.-K. Joo

AbstractWe studied on the effect of a deposition condition of precursor a-Si thin films on the shape and micro-structure of MILC. The a-Si thin films were prepared by Plasma Enhanced Chemical Vapor Deposition (PECVD) with silane and hydrogen as a source gas and the deposition temperature was varied from 100 to 400∼. The a-Si films deposited at a lower temperature showed a tendency to (111) crystals and leaving some a-Si residues in MILC region, while those with higher deposition temperature tended to be crystallized to (110). These differences were explained in terms of original hydrogen content and following structural changes by the dehydrogenation during annealing.


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