Pulsed laser deposition of ZnSxSe1-xand CdSxSe1-xthin films on quartz: measurements of energy gap, absorption coefficient, and refractive index

Author(s):  
M. Ambrico ◽  
V. Stagno ◽  
D. Smaldone ◽  
R. Martino ◽  
G. Perna ◽  
...  
2021 ◽  
Vol 9 (2) ◽  
pp. 46-50
Author(s):  
Muhanad A. Ahmed ◽  
Mohammed F. Mohammed Sabri ◽  
Wathiq R. Abed

In this paper, nanostructured silicon carbide (SiC) thin films are deposited onto glass substrate using pulsed laser deposition technique. Electrical and optical characterizations such as conductivity, resistivity, transmission, Seeback effect, absorption, absorption coefficient, energy band gap, and extinction coefficient as a function of photon energy, and the effect of thin films thickness on transmission are carried out to characterize the prepared samples. Results showed that the prepared SiC thin film is an n-type semiconductor with an indirect bandgap of ~3 eV, 448 nm cutoff wavelength, 3.4395 × 104 cm−1 absorption coefficient and 0.154 extinction coefficient. The surface morphology of the SiC thin films is studied using scanning electron microscope at a substrate temperature of 400 °C and it is found that the grain size of the prepared SiC thin film is about 30 nm. As such, the nano thin films optical and structural characteristics enable the films to be used as gases sensors in many optoelectronic devices such as the environment and ultraviolet photodiode.


2007 ◽  
Vol 14 (06) ◽  
pp. 1079-1082 ◽  
Author(s):  
HONGXIA LI ◽  
XIN WU ◽  
RENGUO SONG ◽  
JIYANG WANG

High-quality Nd:LuVO 4 thin films have been grown on silica glass substrates by using a pulsed laser deposition technique. X-ray diffraction results show that the as-deposited Nd:LuVO 4 film is basically oriented polycrystalline, and strong (200) peak was revealed. The waveguide property was characterized by the prism-coupling method. The refractive index of the propagation mode is higher than that of the silica glass substrate which means that the dips correspond to real propagation mode, where the light could be well defined. The surface morphology of the deposited Nd:LuVO 4 films was also observed by using an atomic force microscopy.


2008 ◽  
Vol 368-372 ◽  
pp. 305-307
Author(s):  
Kan Song Chen ◽  
Hao Shuang Gu ◽  
Jian San Zou ◽  
Li Wang ◽  
Yi Huang

SrBi2Nb2O9 (SBN) thin films were prepared on fused quartz substrates at room temperature by pulsed laser deposition. The crystallization behavior and surface morphology were studied at various oxygen pressures by XRD and AFM. The results indicated that the films had polycrystalline structure with a single layered perovskite phase, and exhibited higher crystalline quality, less rough surface morphology, and larger grain size with increasing oxygen pressure. The optical transmittance of the samples was measured in the wavelength range 200-900 nm, and the dispersion relation of refractive indices and wavelength was found to follow the single electron oscillation model. The energy gap of SBN films grown at oxygen pressure of 5 Pa was estimated to be around 3.88 eV by assuming a direct transition between valence and conduction bands.


Author(s):  
Nahida B. Hasan ◽  
Ghusson H. Mohammed ◽  
Mohammed A. Abdul Majeed

CdO thin films have been deposited at different concentration of SnO2 (x= (0.0, 0.05, 0.1, 0.15 and 0.2)) Wt. % onto glass substrates by pulsed laser deposition technique (PLD) using Nd-YAG laser with λ=1064nm, energy=600mJ and number of shots=500. X-ray diffraction (XRD) results reveal that the deposited (CdO)1-x(SnO2)x thin films cubic structure and the grain size increase with increasing annealing temperature and increasing concentration of SnO2. The optical transition in the (CdO)1-x(SnO2)x thin films are observed to be allowed direct transition. The value of the optical energy gap decreases with increasing of annealing temperatures and increase with increasing concentration of SnO2 for all samples.


2018 ◽  
Vol 16 (37) ◽  
pp. 178-189
Author(s):  
Mahdi Hasan Suhail

In the present work, pulsed laser deposition (PLD) technique was applied to a pellet of Chromium Oxide (99.999% pure) with 2.5 cm diameter and 3 mm thickness at a pressure of 5 Tons using a Hydraulic piston. The films were deposited using Nd: YAG laser λ= (4664) nm at 600 mJ and 400 number of shot on a glass substrate, The thickness of the film was (107 nm). Structural and morphological analysis showed that the films started to crystallize at annealing temperature greater than 400 oC. Absorbance and transmittance spectra were recorded in the wavelength range (300-4400) nm before and after annealing. The effects of annealing temperature on absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constant were also study. It was found that all these parameters decrease as the annealing temperature increased to 500 °C, while the energy gap after annealing increase from 3.4 eV to 3.85 eV.


2000 ◽  
Vol 15 (2) ◽  
pp. 488-494 ◽  
Author(s):  
V. Craciun ◽  
E. S. Lambers ◽  
N. D. Bassim ◽  
R. K. Singh ◽  
D. Craciun

The properties of thin Y2O3 films grown using an in situ ultraviolet (UV)-assisted pulsed laser deposition (PLD) technique were studied. With respect to Y2O3 films grown by conventional PLD under similar conditions but without UV illumination, the UVPLD-grown films exhibited better structural and optical properties, especially for lower substrate temperatures, from 340 to 400 °C. These layers were highly crystalline and textured along the (111) direction, and their refractive index values were similar to those of reference Y2O3 layers. They also exhibited a better stoichiometry and contained less physisorbed oxygen than the conventional PLD-grown layers.


2001 ◽  
Vol 11 (PR11) ◽  
pp. Pr11-65-Pr11-69
Author(s):  
N. Lemée ◽  
H. Bouyanfif ◽  
J. L. Dellis ◽  
M. El Marssi ◽  
M. G. Karkut ◽  
...  

2001 ◽  
Vol 11 (PR11) ◽  
pp. Pr11-133-Pr11-137
Author(s):  
J. R. Duclère ◽  
M. Guilloux-Viry ◽  
A. Perrin ◽  
A. Dauscher ◽  
S. Weber ◽  
...  

2002 ◽  
Vol 720 ◽  
Author(s):  
Costas G. Fountzoulas ◽  
Daniel M. Potrepka ◽  
Steven C. Tidrow

AbstractFerroelectrics are multicomponent materials with a wealth of interesting and useful properties, such as piezoelectricity. The dielectric constant of the BSTO ferroelectrics can be changed by applying an electric field. Variable dielectric constant results in a change in phase velocity in the device allowing it to be tuned in real time for a particular application. The microstructure of the film influences the electronic properties which in turn influences the performance of the film. Ba0.6Sr0.4Ti1-y(A 3+, B5+)yO3 thin films, of nominal thickness of 0.65 μm, were synthesized initially at substrate temperatures of 400°C, and subsequently annealed to 750°C, on LaAlO3 (100) substrates, previously coated with LaSrCoO conductive buffer layer, using the pulsed laser deposition technique. The microstructural and physical characteristics of the postannealed thin films have been studied using x-ray diffraction, scanning electron microscopy, and nano indentation and are reported. Results of capacitance measurements are used to obtain dielectric constant and tunability in the paraelectric (T>Tc) regime.


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