scholarly journals Photothermal Deflection Spectroscopy Study of Nanocrystalline Si (nc-Si) Thin Films Deposited on Porous Aluminum with PECVD

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
S. Ktifa ◽  
M. Ghrib ◽  
F. Saadallah ◽  
H. Ezzaouia ◽  
N. Yacoubi

We have studied the optical properties of nanocrystalline silicon (nc-Si) film deposited by plasma enhancement chemical vapor deposition (PECVD) on porous aluminum structure using, respectively, the Photothermal Deflection Spectroscopy (PDS) and Photoluminescence (PL). The aim of this work is to investigate the influence of anodisation current on the optical properties of the porous aluminum silicon layers (PASL). The morphology characterization studied by atomic force microscopy (AFM) technique has shown that the grain size of (nc-Si) increases with the anodisation current. However, a band gap shift of the energy gap was observed.

1994 ◽  
Vol 336 ◽  
Author(s):  
K. Gaughan ◽  
J.M. Viner ◽  
P.C. Taylor

ABSTRACTWe investigated the optical and electronic properties of amorphous silicon carbide (a-Si1−xCx:H) films produced by plasma enhanced chemical vapor deposition from admixtures of silane and ditertiarybutylsilane [SiH2 (C4H9) 2 or DTBS] using photothermal deflection spectroscopy, electrical conductivity and its temperature dependence as well as photoconductivity. These a-Si1−xCx:H films exhibit low Urbach energies and high photoconductivities similar to films produced with other carbon feedstock sources. We also present our results for hydrogen diluted a-Si1−xCx:H films using DTBS as the carbon feedstock source.


2020 ◽  
Vol 398 ◽  
pp. 140-146
Author(s):  
Kawther A. Khalaph ◽  
Zainab J. Shanan ◽  
Aqel Mashot Jafar ◽  
Falah Mustafa Al-Attar

Recently, lead iodide is the most materials employment in the perovskite solar cell application. This paper has studied the character of preparation, structural and optical properties of pbI2 materials. Structural properties are included investigation of the measurements X-Ray Diffraction (XRD), Scan Electron Microscopy (SEM), Fourier Transform InfraRed spectroscopy (FTIR) and Atomic Force Microscopy (AFM) tests to the PbI2 thin films samples. Optical properties are included the investigation UV-Vis test of the thin film samples deposited on glass substrates and investigated the Absorption, Transmittance and evaluated energy gap (Eg = 2.3 eV).


2018 ◽  
Vol 31 (1) ◽  
pp. 50
Author(s):  
Sarmad M. Ali ◽  
Alia A.A. Shehab ◽  
Samir A. Maki

   The ZnTe alloy was prepared as  deposited thin films on the glass substrates at a thickness of 400±20 nm using vacuum evaporation technique at pressure (1 × 10-5) mbar and room temperature. Then the thin films under vacuum (2 × 10-3 mbar) were annealing at (RT,100 and 300) °C for one hour. The structural properties were studied by using X-ray diffraction and AFM, the results show that the thin films had approached the single crystalline in the direction (111) as preferred orientation of the structure zinc-blende for cubic type, with small peaks of tellurium (Te) element for all prepared thin films. The calculated crystallite size (Cs) decreased with the increase in the annealing temperature, from (25) nm before the annealing to (21) nm after the annealing. The images of atomic force microscopy of all thin films appeared a homogenous structure and high smoothness through roughness values ​​that increased slightly from (1.4) nm to (3.4) nm. The optical properties of the ZnTe at (RT,100 and 300) °C were studied transmittance and absorbance spectrum as a function of the wavelength. The energy gap was found about (2.4) eV for the thin films before the annealing and increased slightly to (2.5) eV after annealing at 300 °C  


2007 ◽  
Vol 336-338 ◽  
pp. 2228-2231
Author(s):  
Xiao Qiang Wang ◽  
De Yan He ◽  
Jun Shuai Li

Si films were deposited by inductively coupled plasma chemical vapor deposition at room temperature with a mixture of SiH4/H2. The microstructure of the film was characterized with Fourier transform of infrared, Raman spectroscopy, atomic force microscopy. We found that SiH4 concentration strongly affects the structure of Si films and nano-crystalline film can be synthesized at room temperature by optimizing the silane concentration. The analysis for optical properties of the films suggested that the optical band gap EOPT of films are distinctively lower than those of amorphous Si films. It has been observed that the EOPT of sample decreases with the increasing of H content in film.


2010 ◽  
Vol 29-32 ◽  
pp. 1883-1887
Author(s):  
Hai Bin Pan ◽  
Yuan Tian ◽  
Guang Gui Cheng ◽  
Li Qiang Guo

Boron-doped hydrogenated nanocrystalline silicon (nc-Si:H) thin films were deposited by plasma enhanced chemical vapor deposition (PECVD). Microstructures of these films were characterized and analyzed by Raman spectrum and atomic force microscopy (AFM). Thickness and resistivity of these films was measured by high-resolution profilometer and four-point probe respectively. The impact of annealing on boron-doped nc-Si:H thin films’ resistivity and the relationship between resistivity and microstructure were investigated. The results show that annealing and the annealing temperature have great impact on resistivity of nc-Si:H thin films as a result of microstructures changing after annealing. Resistivity of nc-Si:H thin films decreases after annealing, but it rises with the increasing annealing temperature in the range of 250°C to 400°C.


1995 ◽  
Vol 403 ◽  
Author(s):  
G. Bai ◽  
S. Wittenbrock ◽  
V. Ochoa ◽  
R. Villasol ◽  
C. Chiang ◽  
...  

AbstractCu has two advantages over Al for sub-quarter micron interconnect application: (1) higher conductivity and (2) improved electromigration reliability. However, Cu diffuses quickly in SiO2and Si, and must be encapsulated. Polycrystalline films of Physical Vapor Deposition (PVD) Ta, W, Mo, TiN, and Metal-Organo Chemical Vapor Deposition (MOCVD) TiN and Ti-Si-N have been evaluated as Cu diffusion barriers using electrically biased-thermal-stressing tests. Barrier effectiveness of these thin films were correlated with their physical properties from Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Secondary Electron Microscopy (SEM), and Auger Electron Spectroscopy (AES) analysis. The barrier failure is dominated by “micro-defects” in the barrier film that serve as easy pathways for Cu diffusion. An ideal barrier system should be free of such micro-defects (e.g., amorphous Ti-Si-N and annealed Ta). The median-time-to-failure (MTTF) of a Ta barrier (30 nm) has been measured at different bias electrical fields and stressing temperatures, and the extrapolated MTTF of such a barrier is > 100 year at an operating condition of 200C and 0.1 MV/cm.


Cerâmica ◽  
2002 ◽  
Vol 48 (305) ◽  
pp. 38-42 ◽  
Author(s):  
M. I. B. Bernardi ◽  
E. J. H. Lee ◽  
P. N. Lisboa-Filho ◽  
E. R. Leite ◽  
E. Longo ◽  
...  

The synthesis of TiO2 thin films was carried out by the Organometallic Chemical Vapor Deposition (MOCVD) method. The influence of deposition parameters used during growth on the final structural characteristics was studied. A combination of the following experimental parameters was studied: temperature of the organometallic bath, deposition time, and temperature and substrate type. The high influence of those parameters on the final thin film microstructure was analyzed by scanning electron microscopy with electron dispersive X-ray spectroscopy, atomic force microscopy and X-ray diffraction.


2021 ◽  
Vol 2114 (1) ◽  
pp. 012012
Author(s):  
Tamara S. Hussein ◽  
Ala F. Ahmed

Abstract In this study, the effect of grafting with Iron (Fe) ratios (0.1, 0.3 and 0.5) on the structural and optical properties of cadmium oxide films (CdO) was studied, as these films were prepared on glass bases using the method of pulse laser deposition (PLD). The crystallization nature of the prepared films was examined by X-ray diffraction technique (XRD), which showed that the synthesis of the prepared films is polycrystalline, and Atomic Force Microscope (AFM) images also showed that the increased vaccination with Iron led to an increase in the crustal size ratio and a decrease in surface roughness, The absorption coefficient was calculated and the optical energy gap for the prepared thin films. It was found the absorption decreases and the energy gap decreases with the increase of doping ratio.


2021 ◽  
Vol 2114 (1) ◽  
pp. 012033
Author(s):  
Abubaker.S. Mohammed

Abstract In this article, the quaternary compound Cu2MSnS4 was prepared in a simple and inexpensive approach, where M is the iron (Fe) and zinc (Zn) atoms by the spin coating method on a glass substrate at room temperature (RT), as a result of replacing Zn atoms by Fe. Quaternary Cu2ZnSnS4 (CZTS) and Cu2FeSrS4 (CFTS) structural and optical properties have been studied successfully. The material has been identified by X-ray diffraction, and it was discovered that CZTS has a polycrystalline Tetragonal (kesterite) structure, whereas CFTS has a Tetragonal (stannite) structure. A reduction in the full width half maximum (FWHM) of the preferred plane implies a high degree of crystallization. The structural properties of the film surface, such as grain size and roughness, were studied by Atomic force microscopy (AFM). The results explain an increase in nanoparticle size and surface roughness when Fe is substituted by Zn in the CZTS structure. The absorption coefficient values of all designed compounds in visible regions are greater than 104/cm, and the results show that the absorbance coefficient increases with Fe add. The CZTS films showed an energy gap of 1.88 eV, and this value became 1.69 eV with substituted Fe instead of Zn.


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