Ytterbium oxide nanofibers: Fabrication and characterization for energy applications

Metal oxide nanomaterials are widely used in many applications of renewable energy. Ytterbium oxide (Yb2O3) also attracts attention due to its similar structure to ZnO (similar to 3,26 eV) and TiO2 (similar to 3,36 eV) in terms of bandgap energy. In this study, Yb2O3 belonging to the lanthanide oxide family was produced as nanofiber forms by using the electrospinning technique, which allows for large-scale production, for the first time. The morphological, structural, optical, and phase properties of the produced nanofibers were investigated via XRD, SEM-Mapping, TEM, FTIR, UV-Vis, and XPS characterization techniques. As a result of these analyses, it was determined that the Yb2O3 nanofibers with a diameter of 125 +/- 15 nm have a cubic crystal structure and a bandgap of 3.32 eV. The results of this study have shown that the Yb2O3 nanofibers are capable of performing performance evaluations in many different energy conversion applications and others

Yeni nesil Cu2MSnSe4-xSx (M=Co2+,Fe2+,Zn2+) NANO alaşımlarının kolloidal yöntemle sentezi ve boya duyarlı güneş hücresi uygulamaları

TEZ 621.31244/SARyKaynakça: 59-64 ss.[Özet Yok

Synthesis of band-gap tunable earth-abundant CXTS (X= Mn+2, Co+2, Ni+2 and Zn+2) nanorods: Toward a generalized synthesis strategy of quaternary chalcogenides

WOS:000456789000063Quaternary structured Cu2XSnS4 (CXTS) nanostructures are important semiconductor materials for energy applications due to their excellent properties such as being earth abundant elements, nontoxic nature and easy production. Here, we first report a general process for the synthesis of quaternary CXTS nanorods by the simple and inexpensive hot-injection method. The chemical structure, morphology, optical, and thermal properties of the CXTS were investigated by XRD, TEM, UV-Vis, FTIR and TGA techniques. These results clearly show that the obtained materials have the same crystal structure and are shaped as nanorods with an average 10-40 nm edge length. This study shows that all of the CXTS nanorods can be synthesized by the same synthesis conditions through the simple and facile hot injection process. (C) 2018 Elsevier B.V. All rights reserved.Karamanoglu Mehmetbey University BILTEM (Scientific and Technological Research and Application Center); TUBITAK (The Scientific and Technological Research Council of Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [217M212]This work is supported by Karamanoglu Mehmetbey University BILTEM (Scientific and Technological Research and Application Center) and TUBITAK (The Scientific and Technological Research Council of Turkey) under project number 217M212

Ternary copper tungsten selenide nanosheets synthesized by a facile hot-injection method

WOS:000393727500066Transition metal chalcogenides are important materials due to their many useful properties. Here, for the first time, we have successfully synthesized P-Cu2WSe4 (CWSe) nanosheets by a simple and inexpensive hot-injection process. Morphology, structure composition and optical properties of the synthesized nanosheets were analyzed by XRD, TEM, AFM, EDX, FTIR and UV-Visible absorption characterization techniques. Characterization results show that the nanosheets were observed with good crystallinity and lacking of impurity. This work demonstrates that P-Cu2WSe4 nanostructures can be synthesized through a facile and simple hot-injection method. These results lead to the possibility of synthesizing a new generation of nanosheets with minimized reaction time and required pressure as alternative energy conversion materials. (C) 2016 Elsevier B.V. All rights reserved.Karamanoglu Mehmetbey UniversityKaramanoglu Mehmetbey University [32-M-16]The authors would like to thank to TUBITAK (The Scientific and Technological Research Council of Turkey) and Karamanoglu Mehmetbey University (Grand Number: 32-M-16) for Scientific Research Foundation

Investigation of optical and device parameters of colloidal copper tungsten selenide ternary nanosheets

WOS:000419363800089Hot injection synthesis route has been successfully applied for the preparation of high quality Cu2WSe4 (CWSe) nanosheets in order to determine their optical characterization and device parameters. Several techniques including XRD, SEM, TEM and SAED were used to characterize these nanosheets. These techniques confirmed that Cu2WSe4 nanosheets crystal shapes of synthesized are rectangular and square sheet and the average crystal size is between 20 and 40 nm. The spin coating technique was successfully used to deposit uniform of Cu2WSe4 thin film. Cu2WSe4 thin film has directly transition with a band gap of 1.64 eV. The dispersion of the refractive index is discussed in terms of the single oscillator Wemple-Didomenico (WD) model. The single oscillator energy and the dispersion energy were estimated. Au/Cu2WSe4/n-Si structures was fabricated and its main electrical characteristics described by using current-voltage (I-V) methods. The forward and reverse bias current voltage (I-V) characteristics of Au/Cu2WSe4/n-Si at room temperature were studied to investigate its basic electrical parameters [i.e. saturation current (), ideality factor (), barrier height (), series ()]. Structural and optical mechanisms were discussed for future applications in optoelectronic devices

A Au/CuNiCoS4/p-Si photodiode: electrical and morphological characterization

WOS:000692204600001In this present work, CuNiCoS4 thiospinel nanocrystals were synthesized by hot injection and characterized by X-ray diffractom-etry (XRD), high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive X-ray spectroscopy (EDS). The XRD, EDS, and HR-TEM analyses confirmed the successful synthesis of CuNiCoS4. The obtained CuNiCoS4 thiospinel nanocrys-tals were tested for photodiode and capacitance applications as interfacial layer between Au and p-type Si by measuring I-V and C-V characteristics. The fabricated Au/CuNiCoS4/p-Si device exhibited good rectifying properties, high photoresponse activity, low series resistance, and high shunt resistance. The C-V characteristics revealed that capacitance and conductance of the photo-diode are voltage-and frequency-dependent. The fabricated device with CuNiCoS4 thiospinel nanocrystals can be employed in high-efficiency optoelectronic applications

Performance-enhanced of triboelectric nanogenerator based on functionalized silicone with pumice for energy harvesting

Triboelectric nanogenerators (TENGs) are one of the technologies of obtaining clean energy, have become one of the interesting methods in recent years. Although TENGs have advantages such as low cost, easy fabrication, lightweight, and wide range of use, their low output values limit their use in commercial applications. In this study, we investigated the output performance of a silicone sealant and glass fiber based TENG by doping pumice to a silicone sealant matrix. According to the experimental studies, the output performance of TENG improved with increasing pumice addition and the highest output voltage was obtained for the TENG fabricated with 2.5 wt% pumice doping silicone. The highest power density was obtained with 2.5 wt% pumice doped silicone as 23.65 mW. Also, it was observed that the TENG output power was increased by 36.9% with pumice doping in the silicone sealant matrix. It was demonstrated that pumice doping has a great effect on surface roughness, dielectric constant, and dielectric loss which affect the TENG performance. As a result of this study, it was concluded that the TENG output performance could be enhanced and fabrication cost could be reduced with pumice as natural doping material

The effect of the triangular and spherical shaped CuSbS2 structure on the electrical properties of Au/CuSbS2/p-Si photodiode

CuSbS2 (Chalcostibite) crystals were synthesized by the hot-injection method as triangular and spherical shaped structures. The crystals were inserted by spin coating technique as interfacial layers between Au metal and p-Si to investigate their electrical and photoresponse properties via I-V measurements under various light intensities. The XRD measurements were performed to show the crystalline structure of the spherical and triangular CuSbS2. The TEM images confirmed the triangular and spherical particle structures of the CuSbS2 crystals. The I-V measurements were performed under dark, 20–100 mW light intensities with 20 mW interval for spherical and triangular CuSbS2 photodiodes. In addition, diode parameters were extracted and discussed in the details. The results highlighted that triangular and spherical shaped structures have good photoresponse to the illumination and can be employed in the photodiode and photodetector applications. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.17401159 217M212Acknowledgements This work is supported by Selçuk University BAP office with the research Project Number 17401159 and TUBITAK (The Scientific and Technological Research Council of Turkey) under project number 217M212

Investigation of optical framework of chalcostibite nanocrystal thin films: An insight into refractive index dispersion, optical band gap and single-oscillator parameters

WOS:000405520400056Herein, we report the synthesis of chalcostibite ( CuSbS2) nanocrystals based on hot injection method and the characterization of CuSbS2 thin films by spin coating technique. The deposited films were subjected to the UV-Vis spectrophotometer, XRD, TEM and SAED for optical, structural, morphological and elemental analysis. XRD pattern showed that CuSbS2 nanocrystals have chalcostibite structures and SAED diffraction spots supported the XRD results. Different optical parameters like extinction coefficient, refractive index, real and imaginary parts of dielectric constant and surface and volume energy loss functions have been calculated applying single term Sellmeier dispersion relation and Wemple eDiDomenico single oscillator model. The obtained results are discussed in detail. The optical dispersion and dielectric properties of the CuSbS2 have been determined by the transmittance and reflectance modes in the range of 300-1600 nm. Thus, the CuSbS2 is transparent up to 40-45% in the visible range. The optical bandgap determined by the optical absorbance spectrum analysis showed that thin films possess direct bandgap of 1.86 eV. The calculated refractive index of thin film varies between 1.76 and 2.11 throughout the spectral region considered. The results presented here permit a better understanding of the properties of the chalcostibite nanocrystals which in turn result in the design of more efficient solar cells. (C) 2017 Elsevier B. V. All rights reserved.Karamanoglu Mehmetbey University, Scientific Research Foundation [32-M-16]; Selcuk University BAP officeSelcuk University [16401044]We want to thank to Karamanoglu Mehmetbey University, Scientific Research Foundation (32-M-16) and Selcuk University BAP office (16401044) for financial support of this work

The Au/Cu2WSe4/p-Si photodiode: Electrical and morphological characterization

Cu2WSe4 nanosheets were synthesized by the hot-injection method and put as interfacial layers between Au metal and p-Si by spin coating technique to investigate their photoresponse and capacitor properties via I-V and C-V measurements, respectively. The XRD were operated to confirm crystalline structure of the Cu2WSe4. The TEM image revealed that the crystalline nanosheet structures of the Cu2WSe4. The I-V measurements were performed under dark and light illumination in the range 20 mW–100 mW light intensities with 20 mW interval. In addition, some diode parameters such as ideality factor, barrier height and series resistance were extracted via a various method and discussed in the details. The C-V measurements were employed for various frequency and voltages. The C-V characteristics of the device confirmed the strong dependence on the frequency and voltage. The results imparted that Au/Cu2WSe4/p-Si can be employed for photodiode, photodetector and capacitor applications. © 2018 Elsevier B.V.17401159 32-M-16 Canon Foundation for Scientific ResearchThe authors would like to thank to Selçuk University BAP office (Project Number 17401159 ) and Karamanoglu Mehmetbey University (Grand Number: 32-M-16 ) for Scientific Research Foundation