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In this study, the electrical properties of an Al/p-Si metal/semiconductor photodiodes with Tetracyanoquinodimethane–Polyvinyl chloride (TCNQ–PVC) and PVC–TCNQ:ZnO interfacial layers were investigated. Growing of the interfacial layers on p-Si were fulfilled using electrospinning method as a fiber form. Al metallic and ohmic contacts were deposited via physical vapor deposition method. Scanning electron microscopy (SEM) pictures of the devices were captured to examine the morphology of the structure. Within the scope of electrical characterization, I–V measurements of the Al/PVC–TCNQ/p-Si and Al/PVC–TCNQ:ZnO/p-Si devices were accomplished both in the dark and under illumination conditions. Various device parameters, such as ideality factor and barrier height values were determined from I–V characteristics. Although the ideality factor values were obtained as 8.47 and 6.85 for undoped and ZnO-doped Al/PVC–TCNQ/p-Si diodes, the barrier height values were calculated as 0.84 for both devices. When a comparison was made between ZnO doped and undoped Al/PVC–TCNQ/p-Si diodes, it was evaluated that the rectification and photoresponse properties of the heterojunction diode was improved with ZnO dopant.

Nanofibers have great importance in the membrane technology used in hydrophobic surface filtration studies applied to water-oil separation products. This study improves upon the hydrophobic properties of electrospun polystyrene-based nanofibers by increasing surface contact angles. As a result, nanofibers have been produced by adding ZnO, MoO3, NiO, SiO2, and TiO2 additives to the polystyrene (PS)/dimethylformamide (DMF) polymer solution at 5% of the mass. Surface contact angle (CA), fourier-transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM) images of the nanofibers were taken. The obtained results were evaluated and show the fiber diameter to range from 555 to 1553 nm. The addition process was observed to be able to affect the polystyrene fiber’s ability to retain water. Moreover, surface contact angle of polystyrene increased to 143° by TiO2 addition. Furthermore, the highest oil-carrying capacity is concluded to have been observed on the SiO2 and MoO3 doped fibers.

The Al/CRNNW/n-Si device with a coronene nanowire (CRNNW) interlayer was fabricated by a physical vapor deposition technique and characterized under dark various illumination intensities via I–V measurements at room temperature. The device has exhibited rectifying behavior and the rectifying ratio values decreased from 1.16 × 103 to 1.44 at 4 V biases by increasing light intensity from 20 to 100 mW. The Al/CRNNW/n-Si device was characterized by various techniques such as thermionic emission theory, Norde, and Cheung technique, and device parameters were obtained. The ideality factor and barrier height values were determined as 21.33 and 0.75 eV, respectively, under dark condition from the thermionic emission theory. The series resistance of the device is obtained as 3090 Ω from the Norde method and 9840 Ω from the Cheung method for the dark condition. The current transport mechanism of the device was discussed in detail for various regions from lnI–lnV plot. The coronene layer can be thought of and improved as interfacial material for metal–semiconductor devices.

Zinc oxide (ZnO) has gained great interest for two decades, and its structural, optical, and electrical properties have been investigated by scientists for technological applications. The optical properties of ZnO provide an opportunity for its application in solar cells, lasers, and light-emitting diodes. We prepared ZnO thin films with various In doping levels by using a spin coating technique, and characterised their morphological and detailed optical properties for optical applications. According to the morphological properties obtained by atomic force microscopy, the film surfaces are homogeneous and the In doping level affects the surface morphology of the films. The optical properties of the films were investigated using an ultraviolet–visible spectrometer, and some optical parameters such as band gap, refractive index, extinction coefficient, single oscillator parameters, real and imaginary functions of the dielectric coefficient, and optical conductivity were calculated and discussed in detail. The various In doping levels affected the optical properties, and the In-doped ZnO thin films can find applications in industry.

The TiO2/p-Si/Ag, graphene nanoparticles doped (GNR) TiO2/p-Si/Ag and multi-walled carbon nanotube (MWCNT) doped TiO2/p-Si/Ag photodiodes were fabricated by electro-spinning technique at the same experimental conditions, and their structural, morphological and electrical properties were compared for photodiode applications. XRD measurements were confirmed undoped, GNR and MWCNT doped TiO2 structures, and brookite phase of (121) preferred orientation TiO2 has been observed from XRD patterns. SEM images of the heterojunctions showed that undoped and doped TiO2 layer have homogenous surfaces. I–V measurements were performed for electrical characterization of the TiO2/p-Si/Ag, GNR-TiO2/p-Si/Ag and MWCNT-TiO2/p-Si/Ag photodiodes under dark and light illumination conditions at room temperatures. The results imparted that all heterojunctions have good rectifying and photodiode properties. Some heterojunction parameters such as ideality factor, barrier height, series resistance were calculated and discussed in details according to thermionic emission theory, Cheung and Norde techniques. The determined ideality factor values are 8.55, 9.70 and 8.99, and barrier height values are 0.75 eV, 0.74 eV and 0.73 eV for the TiO2/p-Si/Ag, GNR-TiO2/p-Si/Ag and MWCNT-TiO2/p-Si/Ag photodiodes, respectively. These heterojunctions can be considered and improved as photodiodes in industrial applications.

The dielectric properties of the Al/PCBM:ZnO/p-Si structure were investigated using the impedance spectroscopy technique. PCBM:ZnO layer was obtained by spin coating method on the p-Si. The morphological properties of the PCBM:ZnO were investigated using atomic force microscopy. The results highlighted that PCBM:ZnO thin film has uniform surfaces. The dielectric parameters such as real and imaginary parts of the electric modulus (M ' and M '') and ac electrical conductivity (sigma), dielectric constant (epsilon '), dielectric loss (epsilon ''), loss tangent (tan delta) values were determined. The results of the dielectric properties of the Al/PCBM:ZnO/p-Si structures impressed voltage and frequency changing. The Al/PCBM:ZnO/p-Si structures can be regarded as a candidate for organic diode applications. Selcuk University BAP OfficeSelcuk University [19401034]; Hitit University BAP OfficeHitit University [FEF.19004.15.010, FEF01.13.003] This study was supported by Selcuk University BAP Office under Project Number 19401034 and Hitit University BAP Office under Project Numbers FEF.19004.15.010 and FEF01.13.003. WOS:000617476200011 2-s2.0-85100549063

WOS: 000485002600023, Undoped and 0.1% 0.5% and 1.0% indium doped ZnO thin films were obtained by spin coating method as interfacial thin film layer between Al metal and p-Si semiconductor to investigate dielectric properties of the Al/In: ZnO/p-Si heterojunctions. Impedance spectroscopy technique was employed to characterize the dielectric properties of the Al/In: ZnO/p-Si heterojunctions depending on frequency (from 10 kHz to 1 MHz) and voltage (from - 5 V to + 5 V). The results imparted that interface states (N-ss), series resistance (R-s), barrier height (Phi(b)) and the concentration of acceptor atoms (N-a) influenced frequency changes. The dielectric parameters such as dielectric constant (epsilon'), dielectric loss (epsilon ''), loss tangent (tan delta), real and imaginary parts of the electric modulus (M' and M '') and ac electrical conductivity (sigma) values were calculated from impedance spectroscopy measurements and discussed in details for changing frequency and voltage for various In doped ZnO thin film interlayers. The dielectric properties of the Al/In:ZnO/p-Si heterojunctions were affected both In doping concentration and the frequency and voltage changes. The Al/In:ZnO/p-Si heterojunctions can be considered for industrial applications to increase the control.

International Congress on Semiconductor Materials and Devices (ICSMD) -- AUG 17-19, 2017 -- Selcuk Univ, Konya, TURKEY, WOS: 000495858400019, This paper sheds new light on how an amount of silica nanoparticles (1, 3 and 5 wt. %) acts on the morphology, the hydrophobicity and on the electrical conductivity of polyacrylonitrile (PAN) nanofibers. In this study, electrospinning technique was used to fabricate nanofibers composites consisting of PAN, dimethylformamide (DMF) and silica at two different applied voltages (15 kV and 20 kV). The scanning electron microscopy (SEM), X-ray diffraction technique (XRD), contact angle technique and the four-point probe technique were respectively used to investigate the morphology and diameter range, the crystalline structure, the hydrophobicity and the electrical conductivity of the obtained nanofibers. At the end, different results of the investigation were compared each other and discussed. (C) 2019 Elsevier Ltd. All rights reserved., Selcuk UniversitySelcuk University [BAP 17201017], Authors acknowledged a financial support received from the research fund of the Selcuk University under Grant No. BAP 17201017.

WOS: 000483376900010, We fabricated undoped and Cu doped TiO2 thin films by spin coating technique and employed the films as interfacial oxide layer between the Al and n-type Si to investigate the effect of temperature on the Al/TiO2/n-Si and Al/Cu:TiO2/n-Si devices. For that aim, the I-V measurements were performed in the range of 50 K-400 K by 50 K interval. The devices exhibited good rectifying behavior and thermal response in a wide range temperature. Ideality factor, barrier height and series resistance were calculated from I-V measurements for various temperatures by thermionic emission theory, Norde and Cheung methods and discussed in the details. The obtained results revealed that the device parameters are a strong function of the temperature. The interface states (N-ss) were affected by the changing of the temperatures. The Al/TiO2/n-Si and Al/Cu:TiO2/n-Si devices can be performed for wide range temperatures in various technological applications., Selcuk University BAP officeSelcuk University [16401044]; Selcuk UniversitySelcuk University, This work is supported by Selcuk University BAP office with Project Numbers 16401044. Authors would like to acknowledge the support of the Selcuk University for this research.

In this study mechanical and thermal properties of epoxy resin reinforced withdifferent numbers of nanofiber layers which produced with electrospinning method wasinvestigated. Solution of 10 wt% of polyacrylonitrile (PAN) in N,N-dimethylformamide(DMF) was used for electrospinning. The diameters of the obtained nanofibers were in therange of 380-420 nm. The average thickness of the produced nanofiber layer was about200 ?m. The special molds were prepared to produce the laminated composite plates. Thetensile tests show that the using of nanofiber PAN layers increase the tensile force 34.54%and decrease the elongation 8.87% in comparison with neat epoxy. The fracture surfaces ofthe specimens were inspected by using optical and scanning electron microscopy (SEM).The thermal properties of the nanofiber layered composites were determined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis. It wasobserved that the glass transition temperature increased parallel to this as the number ofPAN layers increased and rose up to 86?C, while the thermal stability did not show mucheffect of PAN layers., Bu çalışmada elektrospin metodu ile üretilmiş farklı sayılardaki nanofiber takviyelitabakalı epoksi kompozitlerin mekanik ve termal özellikleri araştırılmıştır. Elektrospinişlemi için ağırlıkça %10 oranında poliakrilonitril (PAN) ve N,N dimetilformamid (DMF)çözeltisi kullanılmıştır. Elde edilen nanofiber çapları 380-420 nm aralığındadır. Üretilennanofiber tabaka kalınlığı ortalama 200 ?m’dir. Tabakalı kompozit plakaları elde etmekiçin özel kalıplar hazırlanmıştır. Çekme deney sonuçları nanofiber tabaka kullanımınınçekme kuvvetini saf epoksiye oranla % 34.54 arttırdığı ancak uzamayı saf epoksiye oranla% 8.87 azalttığı belirlenmiştir. Numunelerin kırılma yüzeyleri optik ve taramalı elektronmikroskopu (SEM) ile incelenmiştir. Üretilen nanofiber tabakalı kompozitlerin termalözellikleri termal gravimetrik analiz (TGA) ve diferansiyel taramalı kalorimetre (DSC)analizleri ile belirlenmiştir. Camsı geçiş sıcaklığının PAN tabaka sayısı arttıkça buna paralelolarak arttığı ve 86 C ye kadar çıktığı, termal kararlılıkta ise PAN tabakalarının etkisininçok fazla olmadığı görülmüştür.

Gunumuzde nanofiber komponenler (poliakrilonitril dimetil formamit gibi) bir cok muhendislik alaninda ve gida sektorunde kullanilmaktadir. Cevre ve hedef olmayan organizmalar uzerindeki muhtemel etkilerin belirlenmesi gerekmektedir. Drosophila melanogaster Meigen (Diptera: Drosophilidae) gelisim biyolojisi ve cevre calismalarinda cok calisilan model bir organizmadir. Bu calismada, erginler nanofiber (elektrospinle uretilen 260 nm cap araligina sahip PAN-DMF) kapli diyetle beslenerek yetistirilmis, ergin evreye kadar biyolojik ozellikler gozlenmistir. Nano fiberin etkisi ile D. melanogaster'in yasama gelisme ve hayatta kalma oranlari arastirilmistir. Besin yuzeyi ve canlilik SEM kullanarak goruntulenmistir. Elde edilen sonuclara gore, PAN-DMF kontrolle karsilastirildiginda besin yuzeyinin uygun oldugu gorulmus; ve bocegin gelisim surecini kotu etkilemedigi bulunmustur. Besinle iliskili organizmalarda nanofiberler kullanilabilir, fakat bu bilesenlerin cevre ve hedef olmayan organizmalar uzerindeki etkilerinin anlasilabilmesi icin cok detayli calismalara gerek duyulmaktadir.