scholarly journals Investigation of the Optical, Structural and Compositional Properties of Electrodeposited Lead Manganese Sulfide (PbMnS) Thin Films for Possible Device Applications

2021 ◽  
pp. 18-32
Author(s):  
Laz Nnaedozie Ezenwaka ◽  
Augustine Nwode Nwori ◽  
Ifeyinwa Euphemia Ottih ◽  
Ngozi Agatha Okereke ◽  
Nonso Livinus Okoli

The properties of PbMnS semiconductor thin films deposited on fluorine-doped tin oxide (FTO) substrate using an electrodeposition method are investigated to determine their possible device applications. Lead acetate, manganese sulfate, and thiourea were used as precursors for sources of lead, manganese, and sulfur ions respectively. The concentration of lead, manganese, and sulfur ions sources with deposition voltage of 1.8 V was kept constant. The films were deposited using three electrodes system of electrodeposition method by varying deposition time. The films were characterized for optical, structural, morphological, and compositional properties and results showed that the absorbance, refractive index, and optical conductivity of the films are high in the visible (VIS) and near-infrared (NIR) regions but decreases in the NIR. These three properties initially increased with an increase in deposition time up to a time of 70 s which has the highest values of these properties before decreasing to lower values. The transmittance and extinction coefficient of the films are low in both VIS and NIR regions. The bandgap energy of PbS was found to be blue shifted with values of 1.51 eV, 1.54 eV, 1.60 eV, 1.45 eV, and 1.35 eV for the films deposited at 30 s, 50 s, 70 s, 90 s, and 110 s respectively. XRD analysis showed that the films are crystalline with sharp peaks positions indexable to crystalline planes of (111), (200), (211), (220), (311) and (400) with average crystallite size in the range of 16.110 nm to 17.218 nm. Energy-dispersive X-ray spectroscopy (EDX) results showed that the films are composed of lead, manganese, and sulfur but there are some impurity elements present mostly as a result of the substrate used. These properties exhibited by the deposited thin films of PbMnS showed that they can be used for many optoelectronic applications such as photovoltaic cells, sensors, photoconductors, etc.

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Tizazu Abza ◽  
Dereje Gelanu Dadi ◽  
Fekadu Gashaw Hone ◽  
Tesfaye Chebelew Meharu ◽  
Gebremeskel Tekle ◽  
...  

Cobalt sulfide thin films were synthesized from acidic chemical baths by varying the deposition time. The powder X-ray diffraction studies indicated that there are hexagonal CoS, face-centered cubic Co3S4, and cubic Co9S8 phases of cobalt sulfide. The crystallite size of the hexagonal CoS phase decreased from 52.8 nm to 22.5 nm and that of the cubic Co9S8 phase increased from 11 nm to 60 nm as the deposition time increased from 2 hrs to 3.5 hrs. The scanning electron microscopic images revealed crack and pinhole free thin films with uniform and smooth background and few large polygonal grains on the surface. The band gap of the cobalt sulfide thin films decreased from 1.75 eV to 1.3 eV as the deposition time increased from 2 hrs to 3.5 hrs. The photoluminescence (PL) spectra of the films confirmed the emission of ultraviolet, violet, and blue lights. The intense PL emission of violet light at 384 nm had red shifted with increasing deposition time that could be resulted from the increase in the average crystallite size. The FTIR spectra of the films indicated the presence of OH, C-O-H, C-O, double sulfide, and Co-S groups. As the deposition time increased, the electrical resistivity of the cobalt sulfide thin films decreased due to the increase in both the crystallite size and the films’ thickness.


2013 ◽  
Vol 716 ◽  
pp. 325-327
Author(s):  
Xiao Yan Dai ◽  
Cheng Wu Shi ◽  
Yan Ru Zhang ◽  
Min Yao

In this paper, CdTe thin films were deposited on soda-lime glass substrates using CdTe powder as a source by close-spaced sublimation at higher source temperature of 700°C. The influence of the deposition time and the source-substrate distance on the chemical composition, crystal phase, surface morphology and optical band gap of CdTe thin films was systemically investigated by energy dispersive X-ray spectroscopy, X-ray diffraction, scanning electron microscope and the ultraviolet-visible-near infrared absorption spectra, respectively. At the deposition time of 60 min and the source-substrate distance of 5 mm, the CdTe thin films had pyramid appearance with the grain size of 15 μm.


2021 ◽  
Vol 18 (20) ◽  
pp. 16
Author(s):  
John Damisa ◽  
Joseph Onyeka Emegha

The effects of deposition cycles on the structural and optical properties of lead tin sulphide (PbSnS) thin films have been described. Successive ionic layer adsorption and reaction (SILAR) method was used to deposit the ternary material on soda-lime substrates. In the present work, the PbSnS films were grown using lead nitrate, tin chloride dehydrate and thioacetamide solutions as sources of Pb, Sn and S, respectively. XRD measurements revealed that the deposited films were polycrystalline in nature with strong adherent to the substrates. The transmittance was found to be high in the near infrared regions of the electromagnetic radiation and, also increased with deposition cycles. The band gap energy was found to vary from 1.70 to 1.75 eV for 10 and 35 deposition cycles. The study indicates that SILAR is an excellent method in depositing good quality films for device applications. HIGHLIGHTS SILAR is an excellent technique for depositing thin films of lead tin sulphide (PbSnS) Deposition cycles influences the XRD and optical properties of PbSnS thin films PbSnS thin films are useful for solar cell fabrications The band gaps of the PbSnS varies from 1.70 to 1.75 eV with deposition cycles


2016 ◽  
Vol 675-676 ◽  
pp. 273-276 ◽  
Author(s):  
Tuntumrong Wanchaem ◽  
Songsak Rattanamai ◽  
Paweena Dulyaseree ◽  
Wirat Jarernboon ◽  
Winadda Wongwiriyapan

Manganese oxide (MnOx) thin films were prepared on stainless steel (SS) 304 by galvanostatic (GS) mode of electrodeposition technique using different precursors; 0.1 M potassium permanganate (KMnO4) and 0.1 M manganese sulfate (MnSO4) solutions. The electrodeposition condition was set at a constant current of 1 mA/cm2. Different precursors provide MnOx thin films with different morphologies. Using KMnO4 as a precursor, the MnOx thin film was deposited (MnOx-K), while using MnSO4 as a precursor, the MnOx nanosheets with a thickness of approximately 40 nm were formed (MnOx-S). XPS results evidence the formation of manganese oxide with different oxidation states composition by different precursors. Electrochemical measurements were carried out in a three-electrode setup using Pt and Ag/AgCl electrodes as counting and reference electrodes, respectively and 1M Na2SO4 aqueous solution as electrolyte. MnOx-K at a deposition time of 10 min shows the highest specific capacitance of 233.55±19.01 F/g. The specific capacitance improvement of MnOx-K may be attributed to MnOx nanosheet structure which increases surface area of electrode.


2020 ◽  
Vol 14 (2) ◽  
pp. 119-127
Author(s):  
Queiroz de ◽  
Azevedo de ◽  
Medeiros de ◽  
Igor Nascimento ◽  
Souza de ◽  
...  

Experimental and theoretical investigations of the structure and optical properties of Al-doped ZnO (AZO) thin films produced by magnetron sputtering under different values of electric current were conducted. The XRD results confirm the formation of the AZO thin films with hexagonal wurtzite structure, with preferential orientation along the crystallographic plane (002), direction c. The increment of electric current allowed an increase in average crystallite size. The FE-SEM and AFM images analyses of the AZO films revealed the occurrence of nucleation on the substrate surface that formed films with granular and rough structure. The higher substrate temperature caused by the higher value of electric current had influence on the grain size and thickness (ranging from 974 to 1500 nm) of the formed thin films. Due to the high absorption of free carriers, the optical transmittance of the AZO films was acceptable for the visible spectrum and limited to the near infrared region. The energy band gap values for both AZO films, measured from the optical transmission spectra, were ideal for semiconductor applications. The ab initio calculations using DFT and the method LSDA + U along with the correction of Hubbard were successfully applied to investigate the structural and optical effects. The band structures of the pure ZnO and ZnO:Al, calculated in this work, presented Eg values close to the experimental results. Therefore, these results imply that our methods are reliable and that the calculations are in accordance with the experimental results.


2016 ◽  
Vol 15 (01n02) ◽  
pp. 1650007
Author(s):  
Mohamed Othmane ◽  
Abdallah Attaf ◽  
Hanane Saidi ◽  
Fouad Bouaichi ◽  
Nadia Lehraki ◽  
...  

We investigated the structural, electrical and optical properties of zinc oxide thin films as the n-type semiconductor. In the present paper, the effect of substrate temperature on the synthesis of ZnO thin films was carried out from 250[Formula: see text]C to 500[Formula: see text]C. ZnO thin films were deposited on glass substrates via ultrasonic spray technique with 0.2[Formula: see text]mol/L of zinc acetate dehydrate. The crystal quality of the thin films was analyzed by X-ray diffraction which results in modified substrate temperature. The optical transmittance and electrical conductivity measurements were carried out by Ultraviolet-visible spectrophotometer and four-point methods, respectively. Polycrystalline films with a hexagonal wurtzite structure with (100) and (002) preferential orientation corresponding to ZnO films were observed at high temperature. The optimal values of the average crystallite size of the ZnO films under consideration are observed beginning with 350[Formula: see text]C of substrate temperature. All films exhibit an average optical transparency of about 85% in the visible region. The shift of optical transmittance toward higher wavelength can be shown by the increase of bandgap energy from 3.245[Formula: see text]eV to 3.281[Formula: see text]eV with increasing substrate temperature of 250–500[Formula: see text]C. The observed Urbach energy of ZnO thin films decreases from 0.11311[Formula: see text]eV to 0.04974[Formula: see text]eV. At a high temperature, the electrical conductivity of ZnO films was increased from [Formula: see text] to 41.58 ([Formula: see text].cm)[Formula: see text] with the increasing substrate temperature from 350[Formula: see text]C to 500[Formula: see text]C.


Author(s):  
Karren L. More

Beta-SiC is an ideal candidate material for use in semiconductor device applications. Currently, monocrystalline β-SiC thin films are epitaxially grown on {100} Si substrates by chemical vapor deposition (CVD). These films, however, contain a high density of defects such as stacking faults, microtwins, and antiphase boundaries (APBs) as a result of the 20% lattice mismatch across the growth interface and an 8% difference in thermal expansion coefficients between Si and SiC. An ideal substrate material for the growth of β-SiC is α-SiC. Unfortunately, high purity, bulk α-SiC single crystals are very difficult to grow. The major source of SiC suitable for use as a substrate material is the random growth of {0001} 6H α-SiC crystals in an Acheson furnace used to make SiC grit for abrasive applications. To prepare clean, atomically smooth surfaces, the substrates are oxidized at 1473 K in flowing 02 for 1.5 h which removes ∽50 nm of the as-grown surface. The natural {0001} surface can terminate as either a Si (0001) layer or as a C (0001) layer.


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. 


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