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In this article, a new Schottky diode based on a transparent conducting polymer 2-(4-fluorophenyl)-2-oxoethyl-2-methylprop-2-enoate (PFPAMA) that is doped up to 5% with ZnO is presented. PFPAMA is a promising transparent polymer that is inclined towards n-type behavior with the potential to be used as an electron transport layer. Each device had the Al/p-Si:(PFPAMA:ZnO)/Al structure. The diode ideality factor was found to depend on bias and illumination but the calculated interface state density is lower than for most reported Al/p-Si diodes, suggesting that the presence of the polymer suppresses interface states. The measured electrical and photo response characteristics confirm that the resulting diodes are suitable for fast photodiodes over the intensity range of dark to 100 mW/cm2 whose performance is optimizable by ZnO doping.

We present evidence for the existence of bias and illumination-driven negative differential conductance (NDC) in Ni-doped aluminium/p-Silicon Schottky diodes. We suggest the Ridley–Watkins–Hilsum (RWH) mechanism as a possible explanation of the origin of this NDC. The NDC is dependent on the bias, doping level, and illumination. The dark currents do not show NDC regions, implying that it is a bias and illumination-dependent effect. We use surface plots to visually enhance the parametric trends in the output data. The resultant devices show excellent performance characteristics in both the photoconductive and the photovoltaic modes. The recently reported series resistance compensated method was applied to the I-V characteristics to extract the parameters of the diodes. The results show that Ni doping achieves NDC in reverse bias, between -1.5V to -0.5V, but only at certain doping levels in forward bias. The open circuit voltages of the devices in solar cell mode ranged from 0.03V to 0.6V.

In this study, we examine the performance of organic field-effect transistors (OTFTs), based on pentacene as an active layer. We investigate two different thicknesses of pentacene film (280 nm and 150 nm) deposited on a poly(4-vinylphenol) layer grown on a SiO2 dielectric layer. To compare the functioning of these two pentacene OTFTs (280 nm and 150 nm), we analyze the electrical parameters, particularly the mobility µ, the threshold voltage Vth, the Ion/Ioff ratio, the sub-threshold swing S, the interface concentration of trap states Dit, the total concentration of traps that are filled per unit volume Ntrap and the photoresponsivity R. The calculation of these parameters was under different intensities of white light illumination and for Vg = −14 V. We observed that the OTFT with a thinner layer of pentacene (150 nm) exhibits better performance for Vg = −14 V under 100 mW/cm2 than the other OTFT with a thicker active layer (280 nm). Moreover, we adopt a model based on the variable range hopping approach in order to examine the Gaussian density of states (DOS) distribution, the mobility and the Seebeck coefficient of pentacene OTFTs under obscurity and various intensities of white light illumination. Finally, we explain the strong dependence of the electrical parameters of pentacene OTFTs (the DOS distribution, and the Seebeck coefficient) on both illumination and width of the pentacene film.

ZnO semiconductor thin films with and without Al/Cd additives were produced with sol–gel spin coating technique. Also, photodiodes with and without Al/Cd additives were prepared using the same method. The structural properties of thin films produced were examined with SEM and XRD. Optical properties were tested using UV spectrophotometer, and band gap energies of the films were analyzed using absorbance values obtained. It was observed that the films had hexagonal wurtzite crystal structure, and their band gap energies reduce with increasing amount of Cd added. The electrical characterizations of photodiodes were analyzed with phototransient current (I-t, C-t), current-voltage (I-V), capacitance-voltage (C-V) and conductance-voltage (G/w-V) measurements. The barrier height and ideality factor parameters of the diodes were calculated using thermoionic emission model. The photodiodes exhibited photosensitive behavior, and it was seen that reverse bias current raised due to raising the light intensity. The results demonstrated that the produced diodes can be used as photodiodes or photosensors in optoelectronic implementation.

Nano-structured semiconductor thin films and p-type Si photodiodes were fabricated with the sol-gel spin coating technique using pure ZnO and co-doped ZnO:Alx:Cuy with x = 1 at.-%, y = 1, 2, 3, 5 at.-%. The structural and optical properties of thin films were examined using an XRD and a UV-spectrophotometer. The thin films have a hexagonal wurtzite crystal structure, and their optical band gap energies decrease with increasing Cu contribution. The electrical properties of photodiodes were assessed via I-V, C-V, (G/ω)-V and phototransient current (I-t, C-t) measurements. The Φ b(I-V), experimental zero-bias barrier height, rectification ratio, ideality factor and Ion/Ioff parameters of the diodes were calculated using thermoionic emission model. In addition, Φ b(C-V), barrier height, Vbi, built-in voltage, Vd, diffusion potential, Nd, donor concentration and Wd, depletion layer width of p-Si/ZnO:Alx:Cuy (x = 1 at.-%, y = 1 at.-%.) photodiodes were obtained using a C-2-V graph plotted at 1 MHz frequency. The photodiodes exhibit rectifying and photosensitive behaviors, and their reverse bias current increases with increasing light intensity. These results indicate that produced diodes can be employed as photodiodes or photosensors in optoelectronic circuits and electronic devices.

Al/n-Si/Ti1-xO2CdxO/Al photodiodes were produced using sol-gel and spin coating methods where CdO dopant was applied on different concentrations (x = 0.0; x = 0.01; x = 0.05; x = 0.10). Cd dopant effect upon structural, optical, photodiode and electrical properties was assessed. Scanning electron microscope and energy-dispersive spectra were used in the structural investigation. Optic properties were assessed using UV-Vis spectroscopy and bandgap energies of the photodiodes were calculated which were found to be between 3.25 and 3.36 eV. Increased bandgap energy was observed with increased CdO doping rate. Photodiode properties were assessed under varying daylight illuminations. Barrier height, ideality factor, dark current, linear dynamic rate, photosensitivity, photoresponsivity of the photodiodes were calculated. Electrical properties of the Al/n-Si/Ti1-xO2CdxO/Al photodiodes were calculated where conductance-voltage and capacitance-voltage plots were obtained. Corrective conductance-voltage and corrective capacitance-voltage graphs confirm that the electrical properties of the photodiodes depend on AC signal frequency. Frequency-dependent electrical characteristics were attributed to the density of interface states which were found to be between 10(11) and 10(12). Decreased density of interface state was found for increased AC signal frequency.

Developing a numerical model for thin-film transistors has become significant for optoelectronic applications. In this study, we describe the shift of the Dirac point in a graphene oxide thin-film phototransistor doped with various ratios of poly (3-hexylthiophene) (P3HT) (0.01 and 0.05). According the electrical characteristics of graphene oxide/poly (3-hexylthiophene) thin-film transistors and based on the proposed model, we simulate the carrier concentration, the Fermi level (Ef), the mobility (μ), and the conductivity (σ) of charge carriers, the square resistance, and the Seebeck coefficient as a function of the applied gate voltage in the dark and under the illumination of 100 mW/cm2, using Matlab/Simulink. The results show that, when applying a negative gate voltage, the Fermi level of graphene will shift below the Dirac point, due to the electrical field effect induced by the P3HT molar ratios and the illumination effect. This shift is exhibited more obviously in the mainly simulated parameters, and can be explained by the molar ratios of P3HT, which modulate the displacement field to allow the opening of a transport band gap through a Colombian force created by the oxygen groups. This work can provide a theoretical basis for analyzing the characteristics of these components for application in the logic circuit domain.

A dye sensitized solar cell-based photodiode was prepared using novel [Ru(L1)(L2)(NCS)(2)] complex for solar energy and optoelectronic applications. The new heteroleptic ruthenium(II) complex [Ru(L1)(L2)(NCS)(2)], was synthesized from the reaction of (pyridyl)benzimidazole ligands. The possible usage of [Ru(L1)(L2)(NCS)(2)] complex in dye synthesized solar cell-based photodiode was investigated using electrical and capacitance characteristics. The device was irradiated under various solar light intensities. The change in photocurrent of the device confirms the photoconducting behavior of prepared device. The device exhibited both the photocapacitance and photoresponse behavior with solar illumination. The obtained optoelectrical results suggest that the studied photodiode with [Ru(L1)(L2)(NCS)(2)] complex could be used in optoelectronic device for optical switching and controlling applications. (C) 2021 Elsevier B.V. All rights reserved.

Electrical data of the Schottky structure with CdZnO interlayer have been evaluated for different illumination intensities. Considering such parameters as, the ideality factor (n), reverse saturation current (I-o), zero bias barrier height (phi(Bo)), series and shunt resistances (R-s and R-sh) and surface states (N-ss), we concluded that these parameters extremely depend on the illumination power and applied bias voltage. In consequence of the Ohm's law and Norde's method used for R-s determination, the R-s values decreased with increasing illumination intensity. The energy distribution of the N-ss and voltage dependent profile of resistance (R-i) of the structure were extracted from the forward bias current-voltage (I-V) data. The fabricated CdZnO interlayered metal-semiconductor structure appears to have photodiode behavior. Accordingly, the alteration in the basic electrical parameters by the increment in illumination levels indicates that, the carrier generation takes place in the depletion layer and the conductivity of the CdZnO interlayered structure is improved.

In this research, Sr-doped yttrium nickel oxide-based photodetectors have been fabricated. The electrical properties of diodes have been analyzed by using Cheung and Norde methods. The ideality factors, barrier heights, and series resistances of diodes have been calculated under visible light at different irradiation intensities. In addition, the photoresponse behavior of photodetectors was investigated under visible light at different irradiation intensities. The highest responsivity (R) and detectivity (D*) were calculated as 25.34 mA/W and 7 × 84 1011 Jones, respectively. These results suggest that the photodetectors can be used optoelectronic device applications.

Combination of graphene sheets with various organic/inorganic functional groups could enhance the applications of graphene-based hybrid materials. Among them, BODIPY dyes are critically important due to their unique photonic properties and cyclophosphazenes are an excellent scaffold to anchor two or more chromophores. Thus, many attractive photonic characteristics can be shown in graphene/cyclophosphazene–BODIPY hybrid systems. Herein, the construction, synthesis and development of graphene-based hybrids (GO-CP–BODIPY) for enhanced photosensor applications were shown. Moreover, the photo-electrochemical properties of the novel hybrids were studied in particular using a photoconductivity measurement system. The produced photodiodes were quite sensitive to exposure light and exhibited photoconducting behavior under illumination light. The values of ideality factor and barrier height, which are two of the basic electrical parameters of a photodiode, were determined with the help of current–voltage characteristics for different light intensities. In addition to the dark current, it was found that a photocurrent was formed by the effect of illumination. Furthermore, the capacitance versus time measurements performed at different light intensities showed that the device exhibited photocapacitive behavior. It is considered that the produced device in this study could be used in organic-based optoelectronic applications, especially as a photodiode or photosensor.

Solution-processed organic photodiodes can function as thin-film candidates for solid-state photosensors in various optoelectronic applications due to the physical and chemical tuneability. In spite of their exclusive optical, structural, and electronic properties, the development of BODIPY based organic phodiodes has lagged behind that of other luminescent chromophore units. Here, we demonstrate the design, synthesis, and characterization of new BODIPY decorated triazine tripods for next-generation solution-processed photosensor applications. The photophysical and thermal properties of the BODIPY decorated triazines were determined. Furthermore, the photo-electrochemical properties of the synthesized compounds have been studied in detail using a photoconductivity measurement system. The potential of the prepared diodes as sensors in solar tracking systems has been investigated. Also, quantum chemical calculations were applied to those compounds to examine the effect of both OH groups and different binding positions on those compounds in comparison with experimentally observed data. As a potential application area, the photodiode properties of the designed molecules were tested here. The obtained photoelectrical results indicate that BODIPY decorated triazine tripod based photodiodes can be used as a photosensor in optic control systems.

In this study, Coumarin:TiO2 thin films synthesized by sol-gel method in different coumarin weight ratios were formed by drop casting technique on p-Si. The structural and electrical properties of the synthesized Coumarin:TiO2 thin films were investigated. Nanostructures of synthesized TiO2 were well crystallized at higher Ti concentrations. In addition, photodiode properties of organic-inorganic hybrid Al/p-Si/Coumarin:TiO2/Al samples prepared at varying coumarin concentrations were studied with current-voltage (I-V) characteristics under different illuminations. It was seen that all produced photodiodes had excellent rectifier properties due to the calculated good rectification rates. Also, it was stated that the photocurrents of all produced devices under dark conditions were smaller than those under illumination conditions. Among all the devices fabricated, the highest photosensitivity was observed for photodiode produced with 1% coumarin at under illumination 100 mW/cm2. Electronic parameters such as ideality factor (n) and barrier height (ϕb) were found in ranges 3.1–11.4 and 0.460–0.473 eV, respectively. The temporary photocurrent-time characteristic of the diodes confirmed that the produced devices were light sensitive. Electrical behaviors of the fabricated devices were investigated by means of capacity-voltage (C-V) and conductivity-voltage (G-V) measurements at different frequencies. It was determined that capacity and conductivity decreased and increased, respectively by increasing frequency. This behavior is due to the presence of the interface states of the produced samples. Structural and electrical characterization results showed that all fabricated devices could be operated as optical sensors or photodiodes in optoelectronic fields.

In this research, we have produced Al/CdS nanoparticles-CdO/p-si/Al photodetetor and investigated its optical and electrical characteristics for various optoelectronic applications. The CdO thin film was covered by using sol-gel spin coating method onto the silicon, followed by CdS nanoparticles constitution by the help of SILAR technique. In order to examine the morphological and optical characteristics of fabricated photodetector, the field emission scanning electron microscopy and UV-Vis spectroscopy were utilized, and the band gap of the prepared film was determined as 2,17 eV with the help of these analyzes. The current behavior against the varying voltage values were investigated for the different intensities of solar light conditions and the significant diode parameters were computed by the use of this measurements. As a result of this computation, the barrier height value was found to be 0.49 eV while the ideality factor value was 3.2, and the photoresponse of the photodetector was measured as approximatelly 2.65 × 103. Besides, the transient photocurrent and photocapacitance charactersitics were examined for distinct light conditions. Finally, the interface states were calculated from the capacitance/conductance–voltage (C/G–V) measurements.

Sr doped Y1-xSrxCoO3/p-Si photodiodes were fabricated by the drop-casting technique. The electrical and photoresponse properties of Al/p-Si/Y1-xSrxCoO3/Al diodes were investigated by using current-voltage, capacitance-voltage, and transient photocurrent measurements. The calculated average barrier heights and ideality factors are 0.343 eV (x = 0), 0.356 eV (x = 0.01), 0.386 eV (x = 0.05) and 0.393 eV (x = 0.15), 13.43 (x = 0), 17.27 (x = 0.01), 12.71 (x = 0.05) and 15.75 (x = 0.15) for Al/p-Si/Y1-xSrxCoO3/Al diodes at different illumination intensities, respectively. The lowest ideality factor and series resistance were observed from x = 0.05 doped diode. These results suggest that the Al/p-Si/Y1-xSrxCoO3/Al diodes can be used optoelectronic device applications.

In the current work, the authors studied a hybrid organic-inorganic photodiode combining n-type monocrystalline silicon (n-Si) and indigo dye where the natural dye indigo has been applied as an interfacial layer between Gold (Au) and n-Si. The electrical and photo-response characteristics of photodiode based on indigo dye were investigated through current, conductance and capacitance studies measured under the wide illumination intensity and frequency ranges. The frequency dependency of capacitance-voltage (C-V) and conductance-voltage (G-V) characteristic properties of the Au/Indigo/n-Si photodiode was examined in the frequencies varying from 100 kHz to 1 MHz in view of the effects of series resistance (Rs), the concentration of donor atoms (Nd) and density of interface states (Nss). The C-V and G -V studies indicate that the Nss and Rs are key factors which are strongly influencing the electrical properties of the fabricated Photodiode. From the obtained results, the fabricated Au/Indigo/n-Si photodiode can be a promising contender for electro-optic device engineering.

Diamond-like carbon (DLC) films were electrochemically deposited onto indium tin oxide (ITO) substrates using acetic acid and deionized water as electrolyte at low deposition voltages (2.4 V and 60 V). The transmittance of the films was investigated by UV spectrometry. Transmittance measurements versus wavelength revealed that the films transmit 86 % to 89 % light in visible region and band gap of the films varies between 3.87 eV and 3.89 eV. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used for structural characterization to evaluate surface morphology of the DLC films. The grain size and the surface roughness increased for the films prepared at higher deposition potential, while their measured average height decreased. The mechanical properties (hardness H and elastic modulus Er) were determined from load-displacement curves which were obtained by using nanoindentation method. Hardness and elastic modulus of the films increased as the deposition voltage of the films increased from 2.4 V to 60 V.

Coumarin doped ZnO/p-Si photodiodes were prepared by using the drop casting technique. The effect of coumarin contribution on the photoresponse properties of fabricated Al/Coumarin:ZnO/p-Si/Al organic-inorganic hybrid devices was investigated. Electrical characterization of Al/Coumarin:ZnO/p-Si/Al photodiodes was carried out in the dark and under various illumination intensities with current-voltage (I–V) and capacity/conductivity-voltage (C-G-V) characteristics. The photocurrent of the diodes were found to be higher under illuminated conditions than the dark situation. It was determined that the prepared photodiodes exhibit photovoltaic behavior. Also, the photosensitivity properties of photodiodes were investigated. The highest photosensitivity expressed as Iphoto/Idark ratio was found as 894.73 for the specimen having 3% coumarin weight ratio under the conditions of 100 mW/cm2 and 5 V. Transient photocurrent measurements confirmed that the photocurrent is sensitive to light intensity. In addition, capacitance/conductivity-voltage measurements were accomplished in frequencies between 10 kHz and 1 MHz. As a result of the continuous distribution of interface states, the capacity decreased with increasing frequency. It was determined that all photodiodes produced exhibit a linear photoconductivity behavior. The calculated ideality factors for Al/Coumarin:ZnO/p-Si/Al photodiodes prepared with various coumarin weight ratios exhibited that the non-ideal behaviors due to surface states and oxide layer. In addition, it was understood that the values of the barrier height and the interfacial density of the diodes could be changed with the doped of coumarin. As a result, it is concluded that the produced organic-inorganic devices can be used as optical sensors for optoelectronic applications.

The electrical and photoresponse properties of Al/p-Si/Y1-xSrxMnO3/Al diodes were investigated by using current-voltage and transient photocurrent measurements. The average ideality factor and barrier height has been calculated as 4.2568 and 0.613 eV respectively. The calculated ideality factor for Al/p-Si/Y1-xSrxMnO3/Al diodes is higher than unity because of the interface states, native oxide layer and series resistance. Also, diodes have exhibited property of photosensitivity. These indicated that the fabrication of diodes can be used optoelectronic device applications.

In this letter, we investigated negative capacitance (NC) effect in nanocomposite based quantum dot sensitized solar cells. TiO2 and graphene-TiO2 nanocomposite photoanode based on quantum dot sensitized solar cells (QDSSCs) were fabricated and the capacitance-voltage (C–V), capacitance-frequency (C-f) and conductance-voltage (G/ω-V) characteristics were studied by attention the series resistance (Rs) effect. Admittance spectroscopy of QDSSCs were measured in a variable voltage and frequency ranges of (−2 V) - (+2 V) and 10 kHz-10 MHz, respectively. Capacitance values are exhibited a behavior transition from the positive to negative value after 50 kHz. As the capacitance values decreases, conductance increases in the NC region. Negative capacitance effect of meaning that QDSSC indicates an inductive behavior. Inductive behavior, which means that electrons injects from fluorine-doped tin oxide (FTO) conductive glass electrode to photoanode (graphene-TiO2). Also, NC phenomenon has not form significant effect on Rs.

This article presents a simple and effective method to produce a heterojuction photodiode based on coumarin doped bismuth oxide (Bi2O3) composite. The photoresponse properties of the Au/coumarin doped Bi2O3/p-Si/Al heterojunction can be controlled by applying a voltage and light. The tunable ON and OFF states of the coumarin doped bismuth oxide composite photodiode can be turned into a light-switchable resistive switching. The surface morphology of Bi2O3 doped coumarin thin film was examined using field emission scanning electron microscopy (FESEM). Some of the important electronic parameters such as rectification ratio (RR), ideality factor (n) and the engineered Schottky barrier height ( ϕ B ) were calculated. The capacitance–voltage–frequency measurements showed that the capacitance of the photodiodes depended on voltage and frequency. The results show that the fabricated devices have a photocapacitive behavior which depends on the doping level of coumarin in Bi2O3. It was observed that the photocapacitance of the diode decreased with increasing doping level of coumarin upto 10%. This work demonstrated that more attention should be paid on the influence of coumarin dye on the Bi2O3 and/or other metal oxides for the future fabrication of the photodiodes and optical switching device.

Cu2FeSnS4 semiconductor used in the preparation of quaternary photodiodes was synthesized using hydrothermal synthesis. The nanoparticles were then spin coated on a silicon substrate. Nanoparticles were characterized using SEM and EDX where nanoparticles in granular form were seen. Optoelectronic properties were assessed using UV spectra throughout which bandgap energies were calculated. The band gap energy of Cu2FeSnS4 semiconductor was found as 1.22 eV. I - V and I - t characteristics illustrate that Al/p-Si/Cu2FeSnS4/Al heterojunction photodiodes were responsive to daylight and infrared light. Ideality factor, barrier height, saturation current, and photoresponse values were calculated using I - V and I - t data. The ideality factors were calculated as 5.14 and 5.61 for daylight and infrared light (IR) illuminations, respectively. Electrical properties of diodes were checked using C - V and G - V analysis. It was seen that the electrical properties of photodiodes strongly depend on AC signal frequency. Our assessment revealed that frequency related electrical behavior is originated from interface states. (C) 2021 Elsevier B.V. All rights reserved.

In this study, semiconductor device applications of organic material sunset yellow (SY) (C16H10N2Na2O7S2) has been investigated. The SY thin film was grown on n-Si via spin coating method and the Au/SY/n-Si/Au heterojunction was fabricated. The basic diode parameters of device were determined by the current–voltage (I–V) and capacitance–voltage (C–V) measurements at the room temperature. The values of the ideality factory (n) and barrier height (Φb) were evaluated as 1.15 and 0.70 eV, respectively; and series resistance (Rs) of device was found using Norde functions. The values of built in potential, donor concentration, Fermi energy level and barrier height were also estimated from the linear C−2–V curves with reverse bias room temperature and difference frequency. Furthermore, I–V measurements were applied under different illuminations; some photoelectrical parameters of device were evaluated to understand the photo response properties of the device. Consequently, the results confirmed that the barrier height can be modified by interfacial SY layer, and the device can be used in optoelectronic applications such as optical sensor or photodiode.

In this study, zinc oxide thin films doped with Al at different atomic ratios (0.1%, 0.5%, 1%, 2%, 5%) were prepared using sol-gel spin coating method. Crystal structure, surface morphology, optical properties of the films and their response to ammonia gas were examined. XRD results showed that the ZnO thin films had a hexagonal polycrystalline structure. It was concluded from the calculation of the crystal size and lattice constant of the films that the produced samples were a nanomaterial. Scanning electron microscope (SEM) and atomic force microscope (AFM) images of the samples revealed that the morphology was composed of nanostructured particles and a cluster structure made of the combination of these particles. The optical band gap (Eg) of the prepared films were found within the range of 3.251 eV–3.342 eV by using the optical absorption method. Characteristics of susceptibility against ammonia gas were evaluated depending on the Al dopant. The obtained results showed that the gas response along with the structural, morphological, and optical properties of ZnO thin films changed with Al dopant. The produced thin film samples can be used as a sensor for the detection of ammonia gas in various industrial branches.

CuCdO2 delafossite oxide film as an interface layer was coated by sol-gel spin coating on p-Si substrate, and thus an Al/p-Si/CuCdO2/Al diode was fabricated. Scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) was used to obtain an image of the CuCdO2 oxide film. The temperature-dependent behavior of the diode was studied by current-voltage (I- V) and capacitance/conductance-voltage (C/G-V) measurements over the 100-400 K temperature range. It is observed that the ideality factor (n) decreases and zero-bias barrier height (Ub0) increases with an increase in temperature. This abnormal behavior of n and Ub0 is attributed to barrier inhomogeneities by assuming Gaussian distribution (GD) at the metal-semiconductor interface. For each temperature, the barrier height values obtained from both the conventional I-V and Norde method show good agreement with each other. The I-V-T characteristics have shown the GD, giving a mean barrier height ( similar to U b0) of 1.04 eV and a standard deviation (rs) of 0.12 V. A modified Richardson plot of [ln(I0/T2) similar to q2rs2/2k2 T2 versus q/kT] yields similar to U b0 and A* as 1.06 eV and 31.21 A cm similar to 2 K similar to 2 (indicating an agreement with the theoretical value of 32 A cm similar to 2 K similar to 2), showing the promise of CuCdO2/Si as temperature sensing with a Schottky junction. In addition, C-V and G-V measurements show that the C value decreases and the G value increases as the frequency increases, depending on a continuous distribution of interface states. Also, the capacitance and the conductance values decrease with increasing temperature. The results suggest that Al/p-Si/CuCdO2/Al diode can be used for temperature sensing applications.

The present research focuses on the preparation of ZnO thin films both undoped and doped with varying Cu concentrations (0.0%, 0.8%, 3.0%, 5.0%, 10.0% and 20.0%) using sol–gel spin coating technique. The optical bandgap (Eg) for undoped films is recorded as 3.239 eV and shows a little increase to 3.248 eV when it is doped with 0.8% Cu concentration whereas further increase of Cu doping concentration, it is decreased from 3.248 eV to 3.107 eV for 20% Cu. The EU (Urbach Energy) is improved with the enhancement of Cu doping concentration. Ultraviolet (UV) and bluegreen band emissions are noticed from PL (photoluminescence) spectra. The UV peak intensities are diminished with increasing Cu doping concentration while the blue peaks intensities are amplified. These results illustrate that ZnO films doped with Cu meet the requirement for applications in different blue emission devices.

We report the effect of calcination and carbon (C) incorporation on the characteristic properties of nickel oxide (NiO) consisting of nanowires. The identification of NiO is carried out at room temperature using X-ray diffraction (XRD) and Raman spectroscopy. The images of NiO nanowires are investigated by scanning electron microscope (SEM). It has been observed that the morphology is affected by calcination and carbon incorporation. The optical band gaps vary in the range of 3.22 to 3.42 eV. NiO-based heterojunction is obtained by inserting nanowire structured NiO layer between Al electrode and Si. NiO/p-Si heterojunction shows rectifying behavior in the dark and exhibits prominent photovoltaic response under light. The photovoltaic performance of the NiO/p-Si isotype heterojunction diode is significantly changed with calcination and carbon (C) incorporation of NiO. Results imply that the characteristic properties of NiO as transparent electrode can be improved by doping and calcination for efficient optoelectronic applications.

Zinc oxide (ZnO) is a semiconductor with promising electrical and optical properties. Pure ZnO is an n-type degenerate semiconductor. It is almost entirely transparent in the optical region of the electromagnetic spectrum. In this work sol–gel spin-coating method was used to grow a ZnO thin film from Zinc acetate decomposition. The optical properties of the thin film were extracted and investigated. A ZnO/p-Si heterostructure solar cell was realized using this film and its performance (efficiency) was found to be quite poor. A numerical procedure is used to elucidate this poor performance. A first step is to use the extracted optical parameters in the simulation. However, these parameters did not lead to the reproduction of measured current-voltage and figures of merit of the solar cell by simulation when other parameters of ZnO are taken from literature. It was therefore considered that ZnO is similar to an amorphous semiconductor with a continuous distribution of states in its band gap. The density of states model used is composed of tail bands and Gaussian distribution deep level bands. Eventually, and by adjusting the constituents of the band gap states and by increasing the surface recombination velocity in ZnO/p-Si interface, it was possible to obtain a good agreement between simulated and measured J-V characteristics of this solar cell.

This study was performed to investigate the effects of nanoporous hematite (Fe2O3) the electrical and optical properties on zinc oxide. Zinc oxide powder was commercially obtained. The nanoporous hematite with iron core was prepared using a specific method including ball milling and annealing processes. The particle size of the nanoporous hematite was determined to be 40–50 nm using an electron microscope. The electrical conductivity values of pure ZnO and the composites with 1% Fe2O3, 3% Fe2O3, and 5% Fe2O3 were obtained to be 6.55 × 10−5, 5.35 × 10−4, 3.79 × 10−4 and 1.29 × 10−4 S/cm, respectively. The nanoporous Fe2O3 with iron core increases the electrical conductivity of the ZnO-nanoporous:Fe2O3 composites. The optical band gap (Eg) values of the composites were determined by the Kubelka-Munk theory based on the diffused reflectance. As the nanoporous Fe2O3 content is increased, the Eg values of the composites are decreased. The obtained results indicate that the electrical and optical properties of the ZnO semiconductor is improved with the nanoporous Fe2O3.

The fabrication and photoelectrical properties of the photodiodes based on the ternary alloy of semiconductor nanocrystallite Pb0.9Cd0.1S with coumarin dopant were investigated. The structure, stability, melting temperature and optical bandgap of the prepared nanostructure were characterized by X-ray diffraction, thermogravimetric analysis, Infrared, Raman spectroscopy and UV-VIS-NIR spectroscopies. The characterization of the ternary alloy indicates that the crystal structure of the ternary alloy is cubic with some distortion in (111) direction and has a nanosize of 9 nm. The photoelectrical characteristics of fabricated Si-based photodiodes with coumarin doped PbCdS interfacial layers were investigated by using current–voltage, transient photocurrent and capacitance/conductance-voltage measurements. Some electrical parameters and the effects of illumination on these parameters have been determined from these measurements. Consequently, results of experiments suggest that the ternary alloy Pb0.9Cd0.1S nanocrystallite based photodiode can be suitable for optoelectronic applications.

Titanyum esaslı alaşımların biyomalzeme olarak kullanımınıyaygınlaştırmak için son yıllarda gözenekli implant malzeme olarak üretimi veuygulanması üzerine yoğun çalışmalar yapılmaktadır. Ti-esaslı alaşımlar yüksekkorozyon direnci, düşük elastik modülü ve üstün biyouyumluluğu nedeniylemedikal uygulamalarda yaygın olarak kullanılmaktadır. Bu tür alaşımlarözellikle sert doku implantları olarak tercih edilmektedirler. Alaşım gözeneklimalzeme olarak üretildiği zaman vücut içerisinde canlı dokunun ilerlemesine,kan ve besin taşınmasına imkan sağlayacağı ve kemik ile iyi bir bağoluşturacağı bir gerçektir. Bu nedenle bu çalışmada, yüksek saflıkta elementtozları kullanılarak titanyum esaslı TiNb alaşımı üretildi. Üretilennumunelerin mikroyapılarında, başlıca α fazına ilaveten β ve α" fazlarında varlığı tespit edildi. Soğuk presleme basıncının artmasıyla gözenek oranınınazaldığı, basma dayanımlarının arttığı görüldü. Üretilen numuneler mikroyapılarıve basma dayanımları açısından ideal bir implant malzemesi olarak kullanılabileceğianlaşıldı., In recent years,intensive studies have been carried out on the production and application oftitanium-based alloys as porous implant materials in order to promote the useof titanium-based alloys as biomolecules. Ti-based alloys are widely used inmedical applications due to their high corrosion resistance, low elasticmodulus and superior biocompatibility. Such alloys are especially preferred ashard tissue implants. When the alloy is produced as a porous material it isessential that it will allow the passage of live tissue through the body,allowing blood and nutrient transport, and a good bond with the bone. For thisreason, pure titanium and titanium-based Ti-10Nb alloy was produced in thiswork using high purity elemental powders. After the production, the puretitanium structure consisted entirely of α phase, while in the structure of theTi-10Nb alloy, β and α" phases were detected in addition to α phase. Itwas determined that the porosity ratio of Ti-10Nb alloy is higher than that ofpure titanium specimen and the elastic modulus is closer to bone structure. Itwas understood that Ti-10Nb specimen produced would be more suitable as anideal implant material in terms of microstructure and compressive strength.

In this work, 3% Fe doped zinc oxide (ZnO) doped by Nitrogen thin films were grown by reactive radio frequency magnetron sputtering on p-Si substrates. The structural and optical properties of the 3% Fe doped ZnO doped by Nitrogen thin films were investigated by the scanning electron microscope and spectrophotometry. The diodes with the configuration of Al/p-Si/3% Fe-ZnO: N/Al have been fabricated and it has been observed that the diodes exhibit a good rectification. The optical band gap was found to be 3.98 +/- 0.02 eV for 3% Fe doped ZnO: N thin film deposited at the N-2 flow rate of 15 sccm. The electrical parameters of the diode were determined using Cheung's and Norde's method. The capacitance-voltage and conductance-voltage characteristics of Al/p-Si/3% Fe-ZnO: N/Al structure have been investigated in the frequency range 10 kHz-1 MHz. The increase in capacitance at lower frequency is attributed to the density of interface states. It is evaluated that the prepared diodes can be used as nanoscale electronic and optoelectronic devices. Scientific Project Unit of Kirklareli University [Klubap 76]; King Khalid University under the (Research Center for Advanced Materials Science) at King Khalid University, Kingdom of Saudi Arabia [RCAMS/KKU/007-18] This study was supported by Scientific Project Unit of Kirklareli University under project number: Klubap 76. Authors would like to acknowledge the support of the King Khalid University for this research through a grant RCAMS/KKU/007-18 under the (Research Center for Advanced Materials Science) at King Khalid University, Kingdom of Saudi Arabia.

Bu calismada 2,6-bis(benzimidazol)piridinil (NNN) ligantlar ile kararlastirilmis yeni rutenyum nano partukullerin uretildi. Malzemeler NMR, IR, SEM-EDX, TEM ve XRD gibi teknikler kullanilarak yapilari hakkinda bilgi edinildi ve boya duyarli gunes hucrelerinin hazirlanmasinda kullanildi.

Electrochemical deposition technique was used to fabricate titanium doped amorphous carbon (Ti doped a:C) Al/Ti-a:C/p-Si/Al photodiode. The effects of illumination on the current voltage (I-V) characteristics of the Al/a:C/p-Si/Al doped Ti diode for optoelectronic applications were investigated. The reverse current of the diode increased with the increasing illumination intensities when the bias voltage was applied. By using the forward bias I-V characteristics, the ideality factor (n) and barrier height (Of)) of Al/Ti-a:C/p-Si photodiode structure was found as 1,84 and 0,50 eV, respectively. In addition, the capacitance voltage (C-V) and conductance voltage (G-V) measurements of the diode were studied in the frequency range of 100 kHz-600 kHz. The measured values of the capacitance decreased with the increasing frequency. The photoelectrical properties of Al/Ti-a:C/p-Si/Al device indicates that the photodiode investigated in this paper has great potential to be used in optoelectronic device applications and in industry. (C) 2017 Elsevier B.V. All rights reserved. King Khalid University under the (Research Center for Advanced Materials Science) at King Khalid University, Kingdom of Saudi Arabia [RCAMS/KKU/002-16] Authors would like to acknowledge the support of the King Khalid University for this research through a grant RCAMS/KKU/002-16 under the (Research Center for Advanced Materials Science) at King Khalid University, Kingdom of Saudi Arabia.

In this study, the copper-aluminum-manganese-magnesium (Cu-Al-Mn-Mg) shape memory alloy was utilized for the fabricated CuAlMnMg/n-Si/Al structure. The electrical characteristics of the diode were examined by using illumination intensity and frequency dependent current and admittance measurements. Basic electrical parameters such as barrier height (phi b0), ideality factor (n), and series (Rs) and shunt (Rsh) resistances of the generated diode were obtained from the measured current-voltage (I-V) data using thermionic emission (TE) theory. Illumination impact on the diode parameters indicate that the device displays photoconducting behavior. Furthermore, the phi b0 value was established from Norde method. There is a good agreement between phi b0 values acquired from conventional I-V and Norde method. It was observed that the rise in the applied illumination intensity increased the values of Rs and Rsh. In addition, the ad-mittance (Y=G+i omega C) measurements were carried out in a wide frequency range. As a result of the experi-mental measurements, it has been shown that the produced CuAlMnMg/n-Si Schottky diode can be operated in optoelectronic practices, especially as a photodiode. (c) 2021 Elsevier B.V. All rights reserved.

We present a novel resistance-compensated I–V method to extract the series resistance, ideality factor, barrier height and built-in potential of a metal–semiconductor diode. We show that a reduced equation arises from a unique but hitherto unreported symmetry in the Schottky equation when it is written as an ordinary differential equation. In spite of the intense mathematical justification, we show how this new equation is directly applicable to an empirical data set through a simple algorithm. We test the method on two new Schottky diodes, Al/p-Si/Bi 2 Se 3 /Al and Al/p-Si:P3HT/Al, and compare the results of the method with the Cheung–Cheung method. The series resistances were found to change exponentially with applied bias with a rate constant that depends on the incident illumination. The barrier height decreased with bias but was independent of the incident illumination. As a further illustration, using a different diode with the structure Al/p-Si:P3HT/Al, both I–V and C–V measurements were made. The results of the method agree strongly with literature trends when compared to other electrical methods. In addition, the series resistances calculated using the new method show a rare agreement with C–V method when compared to the Cheung–Cheung method, while correctly reproducing the other dependent parameters, such as the photo-conductive response and the interface state density.

SEM (scanning electron microscopy) and DSC (differential scanning calorimetry) measurements were done to characterize the microstructure and transformation temperature properties of the materials. The CuAlMnZn shape memory alloy (SMA) was used as a Schottky contact in Schottky diode fabricating. The electrical behavior of the diode was investigated using current and admittance experiments. Current-voltage (I–V), capacitance-voltage (C–V) and conductivity voltage (G/ω-V) measurements of the produced diode were carried out at room temperature, dark, light and at different frequencies. For the diode we obtained, basic diode parameters such as ideality factor (n), barrier height (Φb), shunt resistance (Rsh) and series resistance (Rs) were calculated. The current-voltage (I–V) measurements showed that the produced diode exhibits a good rectification in dark conditions. The frequency and potential dependence of the C–V and G/ω-V characteristics of this diod were investigated. It was observed that the C–V and G/ω-V characteristics changed significantly with frequency. The increase in capacitance, especially at low frequencies, was attributed to the presence of interfacial states at the metal/semiconductor interface. The Rsh and Rs values were observed to decrease with illumination. The experimental observations showed that the CuAlMnZn/p-Si Schottky diode can be used as a photodiode for optoelectronic applications.

In this study, the electrical attributes and exposed solar light impacts on the electrical properties were examined for the Al/p-Si structure having InGaZnO interlayer with different rates of Ga component. The films demonstrated the high transparency in the visible zone within percentages of 84–92%. The prepared films' optical bandgap values were utilized by the aid of optical data, and it is indicated that the bandgap values increased with Ga dopant increases. The electrical characteristics of the produced device and the effect of illumination intensity on these characteristics were investigated by the usage of current-voltage and transient measurements at different intensities of exposed light and the produced devices exhibited photoconducting behavior. In addition, electrical parameters with high importance level such as barrier height and ideality factor were calculated by the help of current-voltage measurements and their values were established at predictable level. The capacitance-voltage and conductance-voltage measurements of the produced device were made, and it was determined that they are depended on voltage and frequency, and also interface conditions and series resistance parameters having very large effects on electrical characteristics were calculated by the help of these measurements. It was determined that the energy band gap of the InGaZnO having different contents of Ga ingredient coincides with the energy levels of the semiconductor and the electrolyte. The analyzed results confirm that the fabricated Al/InGaZnO (with different rates of Ga)/p-Si/Al devices have high sensitivity to illumination applied and could be used in advancing optoelectronic applications, especially as a photodiode.

Graphene is a sheet-structured material that lacks a forbidden band, being a good candidate for use in radiofrequency applications. We have elaborated graphene-oxide-doped poly(3-hexylthiophene) nanocomposite to increase the interlayer distance and thereby open a large bandgap for use in the field of logic circuits. Graphene oxide/poly(3-hexylthiophene) (GO/P3HT) nanocomposite thin-film transistors (TFTs) were fabricated on silicon oxide substrate by spin coating method. The current-voltage (I-V) characteristics of TFTs with various P3HT compositions were studied in the dark and under light illumination. The photocurrent, charge carrier mobility, subthreshold voltage, density of interface states, density of occupied states, and I (ON)/I (OFF) ratio of the devices strongly depended on the P3HT weight ratio in the composite. The effects of white-light illumination on the electrical parameters of the transistors were investigated. The results indicated that GO/P3HT nanocomposite thin-film transistors have high potential for use in radiofrequency applications, and their feasibility for use in digital applications has been demonstrated. King Khalid University under Research Center for Advanced Materials Science at King Khalid University, Kingdom of Saudi Arabia [RCAMS/KKU/002-16]; Tunisian Ministry of Higher Education The authors would like to acknowledge the support of the King Khalid University for this research through Grant RCAMS/KKU/002-16 under the Research Center for Advanced Materials Science at King Khalid University, Kingdom of Saudi Arabia. Also, this work was supported by the Tunisian Ministry of Higher Education.

A study of optical and gamma rays shielding properties was performed in the glassy system of (70-x)%B2O3-x%Bi2O3-15%ZnO-15%Na2O where x = 5, 10, 15, 20, 25. The samples were prepared by the melt quenching technique. The amorphous nature of the glass samples was proved using x-ray diffraction. The optical absorption spectra were obtained and the band gap was estimated. The effect of bismuth on the structural properties of the studied glasses was investigated through density ρ and molar volume vm. Optical band gap and Urbach energy were evaluated using optical data of UV-Visible measurements. The Gamma ray attenuation coefficient was measured at gamma ray energies 88.99, 302, 356.01, 661.64, 1173.23 and 1332.51 keV emitted from 137Cs and 60Co radioactive sources. The mass attenuation coefficient measurements show that the investigated system exhibits promising shielding properties.