A facile preparation and structural, optical and electrical characterization of undoped and Y-doped CdS thin films are demonstrated through spray pyrolysis changing doping concentration of yttrium ...atoms in CdS structure. X-ray diffraction pattern displays that CdS samples have polycrystalline hexagonal phase and as they are doped by various amounts of Y atoms, a fluctuation is observed in the preferential orientation. Scanning electron microscopy results show that compact and smooth surface morphology in addition to a slight reduction in grain size are obtained with increasing Y-doping up to 5%. Transparency of CdS thin films are noticeably enhanced by doping of 1% Y atoms. However, further increase of Y-doping towards 5% causes less transparent CdS films due to deterioration of crystal quality. Tauc analysis indicates presence of two direct bandgaps for each sample owing to spin–orbit splitting of valence band of CdS. CdS films have bandgaps of 2.48 eV (E
g1
) and 2.85 eV (E
g2
). Whereas E
g1
value decreases to 2.46 for 5% Y-doping, E
g2
value increases to 2.92 eV for the same Y-doping concentration. Photoluminescence data show that an obvious red shift is observed for blue band regardless of Y-doping concentration. 3% Y-doped CdS thin films display the best carrier density of 4.37 × 10
14
cm
−3
and resistivity of 3.78 × 10
3
Ω.cm, which originate from substitutional incorporation of Y
3+
ions at Cd
2+
ions. Therefore, it can be stated that Y-doped CdS thin films exhibit better electrical and optical properties that are of vital importance in thin film-based solar cells as a window layer.
Chemical spray pyrolysis-grown CdS thin films including various quantities of Eu atoms (from 0 to 10 at.%) were synthesized on glass slides. The detailed physical properties of the produced CdS and ...CdS:Eu thin films were explored. Structural analysis showed that Eu-doping enhanced the crystal quality of CdS thin films until 10 at.% Eu-doping and further Eu-doping treatment led to a distortion in the CdS structure. In addition, the crystallite sizes of CdS thin films dropped from 36.2 to 32.4 nm as Eu-doping level increased to 10 at.%. Morphological data showed that increasing Eu-doping remarkably varied the surface morphology of CdS thin films forming smaller grains. Chemical content examinations approved the presence of Eu atoms in CdS structure. From the optical measurements, it was obtained that more transparent CdS thin films with a maximum transmittance of 68% at 820 nm were created after 10 at.% Eu-doping and bandgap values of samples reduced from 2.58 to 2.47 eV with rising of Eu-doping from 0 to 10 at.%. Room temperature photoluminescence data demonstrated the formation of two essential peaks for all the samples, which are in turn related to green and yellow bands. Electrical investigation pointed out that Eu-doping enhanced the carrier density of CdS thin films from 4.38 × 10
13
cm
− 3
to 2.46 × 10
14
cm
− 3
and dropped the resistivity of CdS samples from 2.59 × 10
4
Ω cm to 5.85 × 10
3
Ω cm until 6 at.% and further increment of Eu-doping paved the way to get worse electrical data. Thus, it can be brought a conclusion that Eu-doping not only improved the optical properties of CdS thin films, but also restored the electrical properties, which are able to use in the opto-electronic devices.
Although the topic of brain death (BD) has been increasing in popularity considerably in recent years by the snowballing number of patients suffering from end-organ failure and waiting for organ ...transplantation, the literature indicates insufficient information regarding the comparison of scientific articles focusing on BD, authors’ and nations', even governments’ tendency about this issue.
In the present study, we aimed to make a bibliometric analysis of the articles focusing on the subject of BD, which is one of the most trendy topics in organ transplantation.
The terms "brain death," were searched in Thomson Reuters, Web of Science search engine for the years between 1995 and 2019. All the articles found were subjected to bibliometric analysis.
Web of Science database included 3487 articles. The United States was found to be the most productive country in all methods, and Transplantation Proceedings was the journal that contributed most to the literature on the subject of BD. A positive correlation between publication productivity and gross domestic product/gross domestic product per capita and human development index was found (r = 0.470, P < .05; r = 0.359, P < .05; r = 0.603, P < .001, respectively). Also, there was a negative correlation between the number of published articles and the population of the country (r = –0.083, P < .001).
Although the top country focusing on the subject of BD was the United States in terms of bibliometrics, we found that there is a correlation between the indices measuring the welfare and development level of the country and publication productivity about BD, which means developed countries show more tendency about BD, which is the main component of the definitive treatment of end-organ failure.
This paper presents the structural, morphological, optical and electrical evolution of Ca-doped CdS thin films. Non-doped and Ca-doped CdS samples with various amounts of Ca atoms (from 0 to 10 at.% ...with an increasing step of 2 at.%) were grown by spray pyrolysis route on glass slides. The structural investigation by X-ray diffraction showed that Ca-doping distorted CdS structure until 8 at.% Ca-doping and then a slight improvement in the intensity of (101) peak was obtained for 10 at.% Ca-doping compared to the other Ca-doping samples. Morphological analysis displayed a grain growth for a low amount of Ca-doping whereas higher concentration of Ca-doping led to a reduction in the grain size of CdS thin films. More stoichiometric CdS specimens were obtained after various amounts of Ca-doping according to energy dispersive X-ray spectroscopy data. Transparency of the CdS samples enhanced remarkably with the incorporation of Ca atoms in CdS with a particular concentration of 10 at.%. Tauc’s plot investigation illustrated that the bandgap score of samples changed from 2.54 eV for non-doped CdS to 2.48 eV for 4 at.% Ca-doped CdS thin films. Further increase of Ca-doping doesn’t vary the bandwidth of CdS samples. Photoluminescence data indicated that Ca-doped CdS thin films had lower intrinsic defects compared with non-doped CdS one. The electrical examination demonstrated that the carrier density of CdS thin films increased till 6 at.% Ca-doping and then decreased further increase of Ca-doping. However, resistivity values exhibited the opposite behavior accordingly. In conclusion, it can be pronounced that 6 at.% Ca-doped CdS thin films are the optimum specimen to be used as an effective transparent and conductive material in the optoelectronic devices.
The present work demonstrates a comparison of performance of Cu, In and Ga-doped CdSe thin films-based photodetectors. Structural, morphological, optical and electrical investigation of Cu, In and ...Ga-doped CdSe thin films prepared by close space sublimation on glass slides is also achieved. It is obtained that Cu, In and Ga-doped CdSe thin films have a good crystal quality with a hexagonal structure in the preferred orientation along (002) plane. Morphological examination shows that Cu-doped CdSe thin films grow in the porous microstructure while In and Ga-doped CdSe films possess compact and uniform morphology without any voids. Transparency of In and Ga-doped CdSe films are higher than that of Cu-doped CdSe throughout the entire spectrum. Band gap values of all the samples are determined to be almost 1.72 eV. Photoluminescence data indicate that Ga-doped CdSe thin films display a deep level band at the lowest peak intensity, which is the indication of less defected structure. All the samples exhibit n-type conductivity. Additionally, the maximum carrier density and the minimum resistivity are reached for In-doped CdSe thin films as 1.75 × 10
16
cm
−3
and 6.12 Ω cm, respectively. Rise time of 28 ms and fall time of 25 ms are obtained for Cu-doped CdSe thin films-based photodetector, which are the fastest photoresponse within all the devices. Furthermore, Cu-doped CdSe thin films-based device has a responsivity of 1.20 × 10
–2
A/W and a detectivity of 1.20 × 10
9
Jones that makes Cu-doped CdSe thin films-based device as a strong candidate for high sensitive photodetector applications.
The effect of Ni concentration on the microstructure and wear performance of 13Cr-(0.5-7.0)Ni-W-Mo-Mn-2C white cast iron subjected to homogenization heat treatment was examined. Concentration of Ni ...was altered in the range 0.5-7.0 wt.% to obtain a stable microstructure against for dry sliding wear resistance as long sliding distance. The effect of Ni on the microstructure was analysed by X-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, elemental mapping and hardness. The wear performances were tested under the loads of 40, 90 and 140 N. Differential thermal analysis of samples with dissimilar Ni values was performed. The increase of Ni concentration decreased the secondary arm spacing of dendrites, refined the dendritic structure and raised the eutectic carbide ratio. The greatest wear performance was obtained for the sample having Ni over 6 wt.%.
In this study, the genotoxic effects of sodium benzoate (SB) and potassium benzoate (PB) were investigated in cultured human peripheral lymphocytes using chromosomal aberrations (CA), sister ...chromatid exchange (SCE), and micronuclei (MN). The level of nuclear DNA damage of SB and PB were also evaluated using the comet assay. The lymphocytes were incubated with different concentrations of SB (6.25, 12.5, 25, 50, and 100
μg/ml) and PB (62.5, 125, 250, 500, and 1000
μg/ml). A significant increase was observed in CA, SCE, and MN, in almost all treatments compared to negative controls. SB and PB significantly decreased the mitotic index (MI) in all the treatments, compared to the negative controls. However, neither of the additives affected the replication index (RI). Although SB significantly increased DNA damage, PB did not cause a significant increase in DNA damage. The present results indicate that SB and PB are clastogenic, mutagenic and cytotoxic to human lymphocytes
in vitro.
Inhaled corticosteroids (ICSs) are an effective drug commonly used in asthma treatment. It is known that osteoporotic changes can occur secondary to steroid usage, depending on dosage and duration. ...The aim of this study was to compare radiomorphometric indices and fractal dimension on panoramic images of patients with asthma using ICSs and healthy controls.
A total of 66 dental panoramic radiographs (DPRs) taken from 32 patients with asthma using ICSs and 34 healthy individuals were evaluated in this retrospective study. Panoramic mandibular index inferior and superior (PMI-i,PMI-s), mandibular cortical width (MCW), gonial index (GI), antegonial index (AI), mandibular cortical index (MCI), and fractal dimension analysis (FDA) were measured on DPRs.
PMI-s (p=0.02), MCW (p<0.001), GI (p<0.001) and AI (p<0.001) values were significantly lower in the group of the asthma using ICSs than control group. However, the PMI-i (p ˃0.05) measurement, the MCI (p ˃0.05) and FDA values distribution were similar in both groups.
The use of ICSs in asthma patients can affect bone quality. The evaluation of PMI-s, MCW, GI, and AI on DPR can help determine the effect of this drug on the jawbones in the early period and select dental and surgical treatment plans appropriately.
The impact of surface modification through diverse dyes (Eosin-Y, D205, N719 and N3) on structural, morphological, optical, and electrical properties of CdS/P3HT hybrid solar cells is studied. X-ray ...diffraction (XRD) pattern shows that CdS nanospheres have a hexagonal structure with a preferential orientation of (002) with respect to indium tin oxide (ITO) coated glass slide. Scanning electron microscopy (SEM) results indicate that compact and dense spherical morphologies of CdS occurred, and the P3HT layer also consisted of small spherical grains. The bandgap of CdS is found to be 2.52 eV according to Tauc’s plot analysis. Absorption spectra demonstrate that interfacial modification via each dye leads to an increase in the absorption in the wavelength range of 300–1000 nm. Photoluminescence (PL) data prove that surface modification of CdS nanospheres with diverse dyes causes a decrease in the spectral intensity of PL curve, implying that efficient exciton separation is taking place upon dye loadings. Fabricated devices with and without modification show photovoltaic effects that can be seen from current density-voltage (
J-V
) curves obviously, and the highest power conversion efficiency (
PCE
) is obtained as 0.881% for N719-modified (ITO/CdS/N719/P3HT/Ag) device (almost 70-fold of pristine one) with a short-circuit current density (
J
sc
) of
2.878
mA
/
cm
2
and open-circuit voltage (
V
oc
) of
0.92
V
, respectively. This enhancement can be attributed to a better surface area between CdS and P3HT after dye modification.
Virgin and Sm-doped CdS thin films were prepared by spray pyrolysis route on glass substrates. The influences of Sm-doping amount on structural, topographical, optical and electrical properties were ...examined. It was found from X-ray diffraction data that virgin and 1 and 2 at.% Sm-doped CdS samples grew along (002) plane whereas the preferred orientation changed to (101) starting from Sm doping of 3 at.%. Morphological investigation showed that even though CdS specimen had irregular shaped grains, Sm-doping substantially modified the surface topography of CdS thin films. A maximum transmittance were attained for 4 at.% Sm-doped CdS sample. After Sm-doping, a slight increase was observed in the band gap value of CdS thin films. It was found from the room temperature photoluminescence data that compared to the virgin CdS, the intrinsic defect population of Sm-doped CdS thin films reduced, meaning that more stoichiometric films formed. From the electrical measurements, it was determined that 1 at.% Sm-doped CdS thin films exhibited the best electrical properties, i.e., maximum carrier density and minimum resistivity. Based on all the data, it could be pronounced that 4 at.% Sm-doped CdS displayed the best optical properties, whereas the optimum electrical characteristics were reached for 1 at.% Sm-doped CdS thin films.
