scholarly journals Effect of the Helium Background Gas Pressure on the Structural and Optoelectronic Properties of Pulsed-Laser-Deposited PbS Thin Films

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1254
Author(s):  
Ameni Rebhi ◽  
Anouar Hajjaji ◽  
Joël Leblanc-Lavoie ◽  
Salma Aouida ◽  
Mounir Gaidi ◽  
...  

This work focuses on the dependence of the features of PbS films deposited by pulsed laser deposition (PLD) subsequent to the variation of the background pressure of helium (PHe). The morphology of the PLD-PbS films changes from a densely packed and almost featureless structure to a columnar and porous one as the He pressure increases. The average crystallite size related to the (111) preferred orientation increases up to 20 nm for PHe ≥ 300 mTorr. The (111) lattice parameter continuously decreases with increasing PHe values and stabilizes at PHe ≥ 300 mTorr. A downshift transition of the Raman peak of the main phonon (1LO) occurs from PHe = 300 mTorr. This transition would result from electron–LO–phonon interaction and from a lattice contraction. The optical bandgap of the films increases from 1.4 to 1.85 eV as PHe increases from 50 to 500 mTorr. The electrical resistivity of PLD-PbS is increased with PHe and reached its maximum value of 20 Ω·cm at PHe = 300 mTorr (400 times higher than 50 mTorr), which is probably due to the increasing porosity of the films. PHe = 300 mTorr is pointed out as a transitional pressure for the structural and optoelectronic properties of PLD-PbS films.

2015 ◽  
Vol 29 (24) ◽  
pp. 1550183 ◽  
Author(s):  
Atul Thakur ◽  
Parul Sharma ◽  
Preeti Thakur ◽  
Amit Sharma ◽  
Anil Thakur ◽  
...  

A nanoferrite series of composition [Formula: see text] with [Formula: see text] and 0.4 has been prepared by a hydrothermal method. X-ray diffraction (XRD) confirmed the formation of cubic spinel structure. The average crystallite size is found to be in the range of 28–48 nm. The lattice parameter is found to increase linearly with an increase in [Formula: see text] content. Field Emission Scanning Electron Microscopy micrographs indicate that the samples have almost uniform sized crystallites with uniform grain growth. Fourier Transform Infrared (FTIR) Spectroscopy studies showed two absorption bands close to 603 and [Formula: see text] for the tetrahedral and octahedral sites respectively. Saturation magnetization attained a maximum value of 34.15 emu/g at [Formula: see text] and then decreases for higher concentrations of [Formula: see text] ions. Activation energy for compositions [Formula: see text] and [Formula: see text] are found to be 0.371 eV and 0.471 eV, respectively. For composition [Formula: see text], maximum value of observed density, minimum porosity, maximum value of saturation magnetization, maximum initial permeability and minimum value of coercivity is obtained. DC resistivity is found to be of the order of [Formula: see text]. The obtained results have been explained based on possible mechanisms, models and theories.


2012 ◽  
Vol 209 (12) ◽  
pp. 2521-2526 ◽  
Author(s):  
Shaoxu Hu ◽  
Peide Han ◽  
Shuai Wang ◽  
Xue Mao ◽  
Xinyi Li ◽  
...  

2015 ◽  
Vol 9 (3) ◽  
pp. 2461-2469
Author(s):  
S. R. Gosavi ◽  
K. B. Chaudhari

CdS thin films were deposited on glass substrates by using successive ionic layer adsorption and reaction (SILAR) method at room temperature. The effect of SILAR growth cycles on structural, morphological, optical and electrical properties of the films has been studied.  The thickness of the deposited film is measured by employing weight difference method. The X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) studies showed that all the films exhibit polycrystalline nature and are covered well with glass substrates. The values of average crystallite size were found to be 53 nm, 58 nm, 63 nm and 71 nm corresponding to the thin films deposited with 30, 40, 50 and 60 SILAR growth cycles respectively. From the UV–VIS spectra of the deposited thin films, it was seen that both the absorption properties and energy bandgap of the films changes with increasing number of SILAR growth cycles. A decrease of electrical resistivity has been observed with increasing SILAR growth cycle. 


2018 ◽  
Vol 10 (5) ◽  
pp. 05018-1-05018-4
Author(s):  
B. Y. Bagul ◽  
◽  
P. S. Sonawane ◽  
A. Z. Shaikh ◽  
Y. N. Rane ◽  
...  

2021 ◽  
Vol 91 ◽  
pp. 106077
Author(s):  
Faiza Jan Iftikhar ◽  
Qamar Wali ◽  
Shengyuan Yang ◽  
Yaseen Iqbal ◽  
Rajan Jose ◽  
...  

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