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Purpose: This research focuses on how the currently occurring conflicts in Pakistan are leading to violent acts which in turn affect the society and the economy of the country. Conflicts and violence are becoming a colossal menace for developing countries such as Pakistan and Afghanistan. Design/Methodology/Approach: Moreover, the research has examined, using the tools of comparative analysis, how conflicts and violence affect the economy and society.Findings: The results suggest that conflicts and violence have rendered serious Socio-economic consequences. Conflicts and violence destroy assets, institutions and brutely disturb the social setup of the country by disturbing the socio-economic progress of the nation. Pakistan has been a victim of conflicts and violence since the day of its independence. Whether it is the migration of refugees in 1947, Pak Indo war of 1965, East Pakistan separation in 1971, post 9/11 war on terrorism, Lal Masjid attack in 2008, PNS Mehran terrorist attack in 2011, or the Peshawar Army Public School attack in 2015, Pakistan has suffered great losses both socially and economically. Implications/Originality/Value: The study has contributed towards better understanding of how conflice and violence has affected the socio-economic structure of Pakistan. Acid attacks, violence against women, child abuse, ethnic polarization, Islamic sectarianism, intolerance, and honor killings are a few of the many heinous acts that have not only affected each member of the society in Pakistan but have also proven to be a threat to each sector of its economy.

This work reports the fabrication of Er@CdS films with 0, 1, 3, 5 wt% Er contents incorporated in CdS via spray pyrolysis route. The films were developed successfully with hexagonal structure and preferred growth orientation along (002) plane and crystallites sizes were found in the range 8–13 nm. Raman spectra showed the 1LO and 2LO vibrational bands centered at 300 cm−1 and 600 cm−1; respectively which confirms the synthesis of pure CdS. The optical band gaps of the films were found in range of 2.38–2.41 eV. A clear reduction in the band gap values is observed as with the incorporation of Er in the CdS matrix. In addition, Er@CdS thin films were utilized to construct a high performance photodetector (PD). The fabricated device shows enhanced visible light photodetection in comparison with the pure CdS films based device. The rise and decay time were detected in the range of 0.079–0.32 s and 0.099–0.32 s, respectively. Noticeable enhancements in responsivity (R) and the external quantum efficiency (EQE) were recorded, reaching maximum values as high as 4.95 A/W and 1150% for 3 wt% Er-doped films. This improvement in the PD performance may be due to the reduction in the defects and sulfur vacancies as a result of Er incorporation in the CdS matrix.

Extremism and terrorism have become a serious threat to Pakistan’s security and well-being. Pakistan is situated in an uncomfortable and unfriendly neighborhood and faces an existential challenge from domestic forces of sectional and ethnic militancy and terrorism. These problems started after the 9/11 attacks. The extremists have not only affected the life in tribal areas but have also invaded the well-developed urban cities of Pakistan as well. The lusts for power, religious differences, regional disparities, political instability, illiteracy, foreign involvements, Afghan Jihad of 1975, low socioeconomic indicators, and non-democratic values are a few of the many reasons that have added fuel to the fire of militancy, terrorism, and extremism. More than 75 thousand people in Pakistan have either been killed by terrorist groups or have become a victim of religious militants and extremists. To address these problems Pakistan took a few measures such as the launching of Zarb-e-Azab, amendments to the Unlawful Activities (Prevention) Act, 1967, the establishment of NATGRID, creating awareness about religion, revising Madrassa reforms, etc. All these efforts have solved the problem but only to some extent. There is a dire need for more strict measures not only by the Government but also by the civilians. Together, they need to keep working against these evils because they have eaten up the credibility, economic stability, reputation, well-being and peace of the country.

In the UV-visible-near infrared regions from 245 to 1000 nm, variable-angle spectroscopic ellipsometer (VASE) was used to investigate optical functions of As2S3 and As2Se3 thin films. In the entire measured spectral range, data were analyzed by assembly from several dispersion models. These assemblies comprise individual Tauc–Lorentz supplemented by several Lorentz (TL-group) or single Cody–Lorentz with several Lorentz (CL-group) models. For As2S3 and As2Se3 thin films, the optical parameters were quantified. The model parameters, such as the Lorentz amplitude, resonance frequency, oscillator width, extinction coefficients, refractive indices, and Urbach and optical band energy of both films were obtained. The band gap energy Eg was experimentally determined using the obtained data of CL-group from (αhν)1/2 vs. hν plots. It is found that the band gap energies of As2Se3 and As2S3 were 1.796 and 2.349 eV, respectively. The Eg values for the films were theoretically investigated by the bond statistics of the random covalent network model (CRNM) with the aid of Manca’s relation. Plausible agreement between the experimental and calculated Eg values for both samples was obtained.

Herein, we have developed the thin Gd@PbI2 films on FTO via a facile spin coating route and subjected to various studies. The formation of (001) oriented hexagonal phase Gd:PbI2/FTO films was confirmed by X-ray diffraction & FT-Raman spectroscopy analyses. The size was determined through Scherrer formula in 11–16 nm range. The doping of Gd and its homogeneity was tested and approved by EDX and SEM e-mapping studies. The Gd doping impact on surface morphology was inspected via SEM images and found very low dimension grains formation throughout the films area. Tauc’s formula was employed to obtain energy gap and found in 2.46–2.74 eV for all Gd@PbI2 films. Absorption and refractive indices were estimated in 0.034–1.2 and 1.4–11 between 395 and 2400 nm wavelength regions. Respective dielectric constant and loss values were noted between 3.5 and 112, and 0.13 and 1.4, signify high dielectric constant and low loss values. The optical conductivity was calculated of 1016 order for all Gd@PbI2 films. SELF and VELF related values were also determined. The values of nonlinear optics related parameters were also calculated and revealed that the grown films are potential candidates for opto-nonlinear devices.

Herein, we report a novel method for the synthesis of pure and Tb-doped NiO nanocomposites with homogeneity using a non-toxic material, citric acid, via one-step flash combustion at 550 °C. The single cubic phase was determined by X-ray diffraction (XRD) analysis, confirming the high purity of the synthesized products. A systematic reduction and broadening of the XRD peaks was seen with increasing incorporation of Tb, indicating a decreasing particle size from 26 to 7 nm. The zeta potential was approximately −6.7 mV for pure NiO and 19 mV for 20% Tb-doped NiO NPs. The higher value of zeta potential indicates that the doped samples are more stable in aqueous media than undoped samples. FT-Raman spectra revealed the absence of impurity peaks and peak broadening with increasing Tb concentrations. All Raman modes were red shifted in comparison to bulk NiO. EDX/SEM mapping revealed the presence of Tb and its homogeneous distribution within NiO. FE-SEM and TEM confirmed the spherical morphology of NiO when doped with Tb. The surface area and pore volume of 5 wt% Tb-doped NiO NPs was determined to be 18.5 m2/g and 8.34 × 10−2 cm3/g, respectively. The energy gap varied with Tb-doping and noticed in the range of 3.5–3.6 eV. An intense single emission peak at 396 ± 5 nm for all Tb-doped NiO NPs was observed. Tb-doped NiO NPs demonstrated e r ′ values in range of 30–77 at 4 kHz and 20 to 41 at 6 MHz. Dark and photo current-voltage investigations revealed that Tb-doping significantly enhanced the electrical properties of NiO, making them highly applicable for optoelectronic devices.

High-quality thin film-based photodetectors containing praseodymium doped cadmium sulfide (Pr:CdS) were fabricated through spray pyrolysis and studied for various opto-electrical applications. Field emission electron microscopy (FE-SEM) revealed that the prepared films were highly compacted with an extremely fine nanostructure without any pinhole or crack. X-ray diffraction and FT-Raman spectroscopy studies confirmed the single hexagonal phase of all the films. The crystallite size was found to lie between 19 and 32 nm. Optical spectroscopy revealed that the fabricated films have low absorbance and high transmittance (in range of 70–80%). The energy gap was found to lie in the range of 2.40–2.44 eV. The PL spectra contained an intense green emission band at ~531 ± 5 nm (2.33 eV), and its intensity was enhanced by increasing the Pr doping content in CdS. The dark and photo currents of CdS increased by approximately 950 and 42 times, respectively with the addition of 5.0 wt% Pr. The responsivity (R) and specific detectivity (D*) were remarkably enhanced to 2.71 AW-1 and 6.9 × 1011 Jones, respectively, for the 5.0 wt% Pr:CdS film. The external quantum efficiency (EQE) of 5 wt% Pr:CdS films was 43 times that of pure CdS films, and the on/off ratio was 3.95 × 102 for 5.0 wt% Pr:CdS film. Its high R, D*, and EQE values, and photo-switching behavior make Pr:CdS a good contender for high quality photodetector applications.

This manuscript reports the bioaccumulation levels of toxic metals by five red algae (Rhodophyta) species (Corallma, Gracilaria, Hypnea, Jania, and Laurencia) at the Sudanese coastal line of the Re...

Herein, novel Ag-doped PbS (Ag:PbS) nanoparticles (NPs) were synthesized via a facile and rapid microwave route. Field emission scanning electron microscopy (FESEM)/energy-dispersive X-ray (EDX) spectroscopy were employed to confirm the homogeneous doping of Ag in PbS. The transmission electron microscopy (TEM) exposed that the PbS NPs were fully encapsulated with Ag. X-ray diffraction (XRD) analysis revealed that all the samples possessed cubic crystal structures whereas the peak positions for the Ag:PbS were slightly shifted towards lower angle compared to pure PbS, further confirm the Ag doping in NPs. Fourier-transform Raman (FT-Raman) spectra also confirmed the phase and doping of Ag in PbS NPs. The grain sizes of the synthesized NPs were found to be in the range of 15–40 nm while calculated crystallite sizes of these samples were in the range of 18–26 nm. The zeta potential for 5.0 wt% Ag:PbS NPs was found to be approximately 10 times higher than that for pure PbS NPs, signifying the high stability of the doped NPs in aqueous media. The optical band gap of Ag:PbS NPs were evaluated from diffused reflectance spectra and found to be in range of 1.95–2.51 eV; increases with Ag doping. The quenching in photoluminescence (PL) intensity was observed with the increase of Ag doping concentration attributed to the charge transfer between Ag and PbS. Moreover, Ag doping also improve the electrical and dielectric properties of PbS NPs. Finally, optoelectrical properties of synthesized materials were investigated under 633 nm laser-light illumination to determine their applicability as visible-light photodetectors. It was found that the Ag doped PbS NPs exhibited enhanced photodetector figures of merit compared to the pure PbS NPs.

The synthesis, characterization, and photodetector application of pure and Ni doped CdS thin films prepared by the spray pyrolysis technique are presented in this paper. Various techniques were used to analyze the thin films that had been produced. The hexagonal phase of the produced thin films is confirmed by X-ray diffraction (XRD) and FT-Raman (FTR) measurements. Scanning electron microscopy (SEM) was used to investigate the morphology of the thin film surface, revealing the development of nanograins. The energy band gaps for all of the prepared thin films were calculated to be approximately 2.4 eV. When the films were stimulated at 450 nm wavelength, a strong photoluminescence emission was seen at ∼540 ± 6 nm. The dark/photo I-V electrical performance of the developed films was observed. The fabricated Au/CdS/Au and Au/Ni:CdS/Au photodetectors were studied for recombination behavior, dark and photo surface resistivity, and photosensitivity. Interestingly, the dark surface resistivity was found to be greater compared to the photo-resistivity. When the light intensity was increased to 1450 Lux, the photosensitivity improves from 10% to 35%. These findings indicate that the fabricated CdS/Ni:CdS films-based photodetectors are suitable for optoelectronic devices.

Taking advantages of non-destructive techniques, between-bottles homogeneity tests were carried out in term of elemental composition of seven certified reference materials (CRMs) candidates using p...

Herein, we present the results of high-performance visible light photodetector fabricated from the grown TlGaSSe single crystal for the first time. The growth direction was found to be (1 0 0) and layered structure was confirmed by scanning electron microscope (SEM) micrograph. The photocurrent observed to be increased with increasing the light intensity and voltage. The photo responsitivity (R), detectivity (D) and external quantum efficiency (EQE) were studied for the fabricated device. The maximum value of R is found to be ∼980 mA V−1. The D value shows a decrease with increasing the light intensity and found in a range of 4.41 × 1011 to 8.48 × 1010 Jones. Further, the maximum value of EQE was found ∼193% at a light intensity of 10 μW cm−2. Photoswitching behavior of the device was also studied and displayed that the ratio of on and off photo values ∼45:100. The values of growth and decay time were found to be ∼218 and 185 ms, respectively.

The optical properties of TlGaSeS at room temperature in the 0.96–5.05 eV photon-energy range has been investigated using variable angle spectroscopic ellipsometry (VASE). The obtained results of dielectric spectra data display different structures at critical points energies. The results are analyzed with reference to three models of the interband transitions in crystal semiconductors, namely, harmonic oscillator approximation (HOA), standard critical-point (SCP) model and critical-point parabolic-band (CPPB). Results are in plausible agreement with the both SCP and CPPB computations over the whole range of the photon wavelengths. Dielectric- correlated optical parameters of TlGaSeS, such as the absorption coefficient, the refractive index, and the orthogonal-incidence reflectivity are illustrated and investigated.

A special new design from melt based on the Bridgman technique has been applied to prepare Tl2Te3 single crystals. The grown crystals were characterized by XRD, SEM, EDAX. The electrical conductivity, Hall effect and thermoelectric power have been performed over the temperature ranges from 93 K to 448 K and 129 K to 468 K respectively. Many physical constant (such as the energy gap, the depth of the impurity level, the Hall coefficient, the conductivity type, the diffusion length, the diffusion coefficient, the scattering mechanism of the charge carriers and their concentrations, the mobility, effective mass, and the lifetime of the majority and minority carriers) have been estimated. The results show that the prepared Tl2Te3 single crystals can be used in the fabrication of electronic devices. Keywords: Semiconductors, XRD, SEM, EDAX, Electrical conductivity, Hall effect, Tl2Te3 single crystals

The optical properties of Ge15Sb5Se80 (GSS) and Ge15Sb5Te80 (GST) films prepared by thermal evaporation method were investigated in the photon energy range from 0.9 eV to 5 eV by using a variable-angle spectroscopic ellipsometer. Combinations of multiple Gaussian, and Tauc–Lorentz or Cody-Lorentz dispersion functions are used to fit the experimental data. The models' parameters (Lorentz oscillator amplitude, resonance energy, oscillator width, optical band gap, and Urbach energy) of both GSS and GST films were calculated. Refractive indices and extinction coefficients of the films were determined. Analysis of the absorption coefficient shows that the optical absorption edge of GSS and GST films to be 1.6 eV and 0.89 eV, respectively. Manca's relation based on mean bond energy and the bond statistics of chemically ordered model (COM) and random covalent network model (CRNM) is applied for the estimation of the optical band gap (Eg) of the investigated films. A good agreement between experimental and calculated Eg is obtained.

Visible-light photodetectors are in great demand in current scenario for advanced optoelectronic devices. Hence, in current work we have fabricated the photodetectors based on Cadmium Sulfide (CdS) thin films with different contents of Yttrium (Y) doping. Hexagonal phase confirmation of the fabricated films was confirmed by X-ray diffraction and FT-Raman spectroscopy analyses. The crystallite size of grown films was determined and found within the range of 33 nm. Scanning electron microscopy was carried out to analyse the surface morphology of the films and reveals nanograins formation on the surface. Optical absorption/transmission/reflectance spectra were recorded up to near-infrared region and optical energy gap was estimated including several other optical parameters. PL spectra were recorded and an intense emission was observed at 542 ± 12 nm when excited at 350 and 450 nm both. The electrical characteristics were explored under dark and light conditions. The highest photoelectrical resistivity and sensitivity were observed for 5.0 wt.% which are around ∼9.45 × 107 Ω−1 and 55.07 % at 0.5 mW/cm2. However, the highest responsivity, external quantum efficiency and detectivity was observed for 3.0 wt.% and noticed around 0.83 A/W, 193.82 % and 4.28 × 1011 Jones, respectively. Outcomes reveal that the Y doping enhances the CdS photodetection nature.

Pure and Cu-doped Poly Vinyl Alcohol (PVA) film samples with different concentrations of copper (5%, 10%, 15% and 20% weight percent) were prepared by the conventional castling technique. The structural, optical and photoconductive properties of pure and doped films were studied. X-ray diffraction pattern of the investigated samples reveals the interaction between the filler and polymer which leads to decrease the crystallinity with riching amorphous phase. Optical spectrophotometric measurements showed blocking of UV range in transmission spectra of 20% wt Cu-content where the determined indirect Optical energy gap strongly decrease from 4.96 eV for pure PVA to about 2.85 eV for this sample. Film samples exhibit positive photoconduction effect where the light reduce the resistance or increases its conduction in addition to that photosensitivity strongly increase by increasing both light intensity and copper concentration in the polymer matrix.

Poly(vinyl alchohol)-starch/magnetite nanoparticles (PVA-St/MNPs) composite film blend with 12%wt. MNPs was fabricated and examined for optical and photoelectric properties. The optical energy gap and Urbach energy were found to be 2.1 eV and 0.55 eV, respectively, suggesting the presence of traps levels distributed in the energy gap. These results also showed that the recombination process could be considered bimolecular. The composite PVA-St/MNPs photo detector showed high photosensitivity in the visible range. The figures of merit were determined by laser light at 532 nm with different intensity levels. The responsivity, external quantum efficiency, and detectivity were found to be 0.36 A/W, 84.1%, and 8.48 × 1010 jones, respectively. These values were found to decrease with increasing laser intensity and applied voltage. The detector showed a fast response to light. The response times of growth and decay were found to be 120 and 154 ms, respectively.

Device grade La@CdS nanostructured thin films with hexagonal wurtzite structure were fabricated on glass substrates with 0 wt.%, 1.0 wt.%, 3.0 wt.% and 5.0 wt.% La doping concentrations by spray pyrolysis method. Comprehensive experimental investigations were systematically carried out on the prepared films. The obtained results revealed that the grown films demonstrate excellent opto-nonlinear and visible light photo-detection properties. The optical band gap values of the films were obtained using absorbance spectroscopy and were in the range 2.40–2.42 eV. On the other hand, the third order nonlinear optical susceptibility (χ(3)) values of the films were calculated and were found to be between 2.73 × 10−13–1.36 × 10−10 esu and were remarkably enhanced after La doping. The dark and photo currents were recorded as functions of La doping concentrations and the intensity of the light source as well. La@CdS based devices photodetection parameters like, responsivity, photosensitivity, external quantum efficiency and specific detectivity values were also obtained in the range of 0.101–1.02 A/W, 22–215, 22.97–241.0% and 8.98 × 1010–4.17 × 1011 Jones, respectively. The rise and decay times were also considerably improved after the incorporation of La in the CdS matrix.

Variable angle spectroscopic ellipsometry (VASE) was employed to study the optical properties of Ge 30-x Sb x Se 70 (x = 0, 5, 10, 15 and 25) films in the UV–vis-NIR (near infrared) spectral region for photon energies from 0.7 to 5 eV. The spectrum of imaginary parts of dielectric for all films is characterized by several peaks. Two groups of linear combination of oscillators were employed for the analysis of these spectra. First combination consists from one Tauc–Lorentz oscillator with more than one Gaussian oscillators (TL + G). Second one Cody–Lorentz oscillator with more than one Gaussian (CL + G) oscillators. Both groups of models behave very similarly and accurately fit to the experimental data. However the Second group models is more accurate in describing dielectric function in the absorption onset region. The effect of Sb content on models’ parameters (Lorentz oscillator amplitude, resonance energy, oscillator width, optical band gap, and Urbach energy) is discussed.

TNbZ host glasses within composition 90TeO 2 –10Nb 2 O 5 –10ZnO in mol% codoped with x(Tm 2 O 3 /Dy 2 O 3 ), where x = 0, 10000, 20000 and 30000 ppm were prepared by using melt-quenching technique under dry oxygen streem. The thermal and optical properties of these glasses were estimated by using differential scanning calorimetric, DSC, and UV–vis-NIR spectroscopy respectively. The results of thermal analysis indicates that Tm 3+ /Dy 3+ modified TNbZ host glass has high thermal stability and anticrystallization process. The density, oxygen packing density, molar volumes, oxygen molar volume, molar refraction, metallization criterion, molar polarizability, linear refractive index n, third-order non-linear susceptibility and two photon absorption coefficient were calculated. It was found that, the linear refractive index increases otherwise decrease in the optical energy gap with increase Tm 3+ /Dy 3+ ions. Raman scattering spectra and calculated Raman gain spectra of present glasses were studied. Addition of Tm 3+ /Dy 3+ ions to TNbZ glasses increase in intensity due to distortion of [TeO 4 ] units, Te-O-Te chains and [TeO 3 ] units. The evaluated Raman gain coefficient of these glasses was found as 33–80 times that of fused-silica (0.89 × 10 −13 m/W) at 440 cm −1 . The results suggest that the present glass modified by Tm 3+ /Dy 3+ may be promising candidate use in optical application like that Raman gain amplifier.

Herein, the optoelectrical investigation of cadmium zinc telluride (CZT) and indium (In) doped CZT (InCZT) single crystals-based photodetectors have been demonstrated. The grown crystals were configured into photodetector devices and recorded the current-voltage (I-V) and current-time (I-t) characteristics under different illumination intensities. It has been observed that the photocurrent generation mechanism in both photodetector devices is dominantly driven by a photogating effect. The CZT photodetector exhibits stable and reversible device performances to 632 nm light, including a promotable responsivity of 0.38 AW−1, a high photoswitch ratio of 152, specific detectivity of 6.30 × 1011 Jones, and fast switching time (rise time of 210 ms and decay time of 150 ms). When doped with In, the responsivity of device increases to 0.50 AW−1, photoswitch ratio decrease to 10, specific detectivity decrease to 1.80 × 1011 Jones, rise time decrease to 140 ms and decay time increase to 200 ms. Moreover, these devices show a very high external quantum efficiency of 200% for CZT and 250% for InCZT. These results demonstrate that the CZT based crystals have great potential for visible light photodetector applications, Authors from KKU express their appreciation to the Deanship of Scientifc Research at King Khalid University for funding this work through research groups program under grant number R.G.P. 2/42/40

TlInSeS optical properties at photon energy ranges from 0.96 to 5.06 eV have been determined by means of variable-angle spectroscopic ellipsometry (VASE). This energy range contains the fundamental band gap. The measured pseudo-dielectric e(E) spectrum depicts different peaks. The spectrum is analyzed with reference of two inter-band transitions models that postulated for crystal semiconductors, explicitly, critical point parabolic band (CPPB) and standard critical-point (SCP) models. It is noted that both dielectric function models illustrates the plausible agreement with the experiment e(E) spectra. The optical properties of the present sample as extension coefficient refractive index absorption coefficient and the normal-reflectance, are investigated. The elemental composition of TlInSeS system has been confirmed by means of Energy Dispersive X-ray fluorescence spectrometer (EDXRF).

Herein, the effect of Terbium (Tb) doping on the photodetection properties of Ag/CdS/Ag devices have been elucidated. An enhancement in the photodetector performance was noted for Ag/Tb@CdS/Ag device in terms of amplified sensitivity of 592, improved responsivity of 3.64 A/W, and excellent detectivity of 6.39 × 1012 Jones in compared to pure Ag/CdS/Ag device with respective values of 192, 0.24 A/W and 7.98 × 1011 Jones. Moreover, the Tb-doped device exhibits a faster response time of 30 ms as compared to 421 ms for device with pure CdS. The enhancement in photodetector performance was explained through the change in conduction mechanism from Schottky in Ag/CdS/Ag to ohmic in Ag/Tb@CdS/Ag device.

This paper reports the preparation of cadmium sulfide (CdS) thin films using a nebulizer spray pyrolysis technique by varying gadolinium content in the range of 0–5 wt.%; their characterization is also described. In this study, the effect of Gd concentration on structure, vibrational, optical linear, and nonlinear properties is investigated. The XRD examination of undoped and Gd-doped CdS films shows the crystalline nature toward the (002) plane. Other important parameters, such as crystalline size (D), strain (ϵ), and dislocations density (δ), were evaluated by XRD, and these results are thoroughly discussed. The SEM studies show the morphology of grains. It was observed that the size of grains increased with an increase in doping concentration. Owing to Gd doping in CdS, the optical energy gap is observed to be lower than that of pure film, which is in the range of 2.416–2.283 eV. The linear and nonlinear properties of CdS: Gd films indicated that Gd doping affected optical properties. The observed enhancement in opto-electrical properties, changes in crystalline quality, and optical property enhancements are caused by an increase in Gd doping concentration.

Achievement of high-performance photodetectors based on CdS is a key field of research and challenge in the current scenario. Here, facile fabrication and characterization of novel samarium (1, 3 and 5 wt.% Sm)-doped CdS thin films for the photodetector applications have been demonstrated. The fabricated films show good crystallinity with crystallites size ranging 18–30 nm. The morphology and homogeneity of Sm-doping ingrown films were confirmed through scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX). Field emission SEM study reveals the low dimension nanograins formation and the films are free from voids and cracks. The effects of Sm-doping on linear and nonlinear optical properties of the fabricated thin films have been elucidated. The optical parameters such as refractive index, energy gap, susceptibilities were noticed to be reduced by Sm-doping in CdS thin films. An emission peak around 536 ± 14 nm was observed in PL spectra of pure CdS which was found to be shifted and quenched by Sm-doping. Finally, the photodetector performance of the fabricated thin films has been investigated for 532 nm laser light. The photodetector based on the 1 wt.% Sm:CdS shows an improved performance (higher responsivity of 1.01 AW−1, higher detectivity of 2.21 × 1012 Jones, excellent photosensitivity of ∼4.9 × 103, and very high external quantum efficiency (EQE) of 257 %) compared to pure CdS (responsivity of 0.213 AW−1, detectivity of 7.43 × 1011 Jones, photosensitivity of ∼2.0 × 103, and EQE of 249.70 %). These results propose a much simpler route to achieve high-quality CdS films for photodetector applications.

In current work a thermal evaporation technique has been employed to fabricate the thin films from the grown TlGaSe2 single crystal and investigated. X-ray diffraction study revealed the formation of polycrystalline films of monoclinic crystal system. The crystallite size was estimated to be 11 nm. Atomic force and scanning electron microscopy studies shows the nanocrystalline film fabrication and the size of grain was estimated. Optical study shows that the grown film is about 55% transparent in 800–1500 nm region and possess a sharp absorption edge. The direct energy gap of TlGaSe2 films was estimated around 2.31 eV. The photo current of the fabricated TlGaSe2 photodetector increases about 6 times compare to dark when exposed under 5 mW/cm2 illumination. The fabricated detector possesses high external quantum efficiency of 158% and also the detectivity reached to 5.16 × 1010 at V = 10 V. The on/off behaviour of the device was also studied and found that the response time for growth and decay is 88 ms and 90 ms, respectively.

This communication demonstrates the potentials of hybridizing (or modifying) poly (vinyl alcohol)/starch composite with magnetite nanoparticle (PVA/St-MNP) to prepare semiconductor and photoconductor polymeric films. The collection of materials composing the newly prepared composite demonstrated satisfactory electrical and photo conductivity and photo sensitivity for optoelectronic applications. The films were prepared with varied contents of magnetite nanoparticles via a solution mixing and casting evaporation method. The structures and morphological surfaces of the films were assessed using FTIR, TGA/DSC, SEM and XRD. The conductivity behavior and light response of the prepared composite films were studied. The current density was also studied for the film samples with different concentrations of MNPs at different applied fields. The current density was found to be dependent on both the field and the MNP content. The results showed a high photo sensitivity of the composite films towards white light. The photo sensitivity of the prepared film samples was found to increase with increasing the MNP content, and reached 14 at 1300 lx for the film containing 12% MNP. The dependence of photoconductivity on light intensity confirmed the existence of traps in the composite films. The life time and differential life time of the pure polymer and composite blends were determined to be within the range 0.67–0.78 and 3.7–457 S. respectively, by studying the transient photoconductivity.