Optical characterization of Cu2ZnSnS4 nanocrystals thin film

WOS:000384418600021Synthesis of nanostructured powders of tetragonal Cu2ZnSnS4 (CZTS) nanocrystals was carried out based on the hot-injection process. High-quality CZTS thin films were prepared by spin coating method onto the Corning 1737 glass substrates. CZTS nanoparticles were characterized using X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM) and high resolution TEM. It is observed that a good quality CZTS film can be obtained by spin deposition at room temperature. The optical properties of the film were studied using UV-visible spectra between 300 and 1000 nm wavelength range. The direct optical band gap of the film evolved as 1.49 eV. This value is close to the ideal band gap for highest theoretical conversion efficiency of solar cell. The optical absorption coefficients of the film between 300 and 1000 nm are found to be about 2 and 7.6 x 10(4) cm(-1), respectively. The optical dispersion parameters of the film were also determined by Wemple-DiDomenico single oscillator model.Selcuk University BAP officeSelcuk University [14101020]This work is supported by Selcuk University BAP office with the research Project Number 14101020

Co-60 gamma irradiation effects on the the capacitance and conductance characteristics of Au/PMI/n-Si Schottky diodes

TUGLUOGLU, NIHAT/0000-0001-9428-4347WOS: 000361293000006In this work, the perylene-monoimide/n-Si (100) Schottky structures have been fabricated by spin coating process. We have studied the capacitance-voltage (C-V) and conductance-voltage (G-V) characteristics of the Au/perylene- monoimide/n-Si diodes at 500 kHz before and after Co-60 c-ray irradiation. The effects of Co-60 gamma-ray irradiation on the electrical characteristics of a perylene-monoimide/n-Si Schottky diode have been investigated. A decrease both in the capacitance and conductance has been observed after Co-60 gamma-ray irradiation. This has been attributed to a decrease in the net ionized dopant concentration that occurred as a result of Co-60 c-ray irradiation. Some contact parameters such as barrier height (Phi(B)) interface state density (N-ss) and series resistance (R-s) have been calculated from the C-V and G-V characteristics of the diode before and after irradiation. It has been observed that the UB and N-ss values are decreased after the applied radiation, while the R-s value is increased.Selcuk University BAP officeSelcuk University [11401115]This work is supported by Selcuk University BAP office with the research Project Number 11401115

The synthesis of 4,4-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(N,N-diphenylaniline) organic semiconductor and use of it as an interlayer on Au/n-Si diode

WOS: 000469399700037In the present study, firstly, a 4,4-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(N,N-diphenylaniline) (FC) organic compound was synthesized and its structural and optical characterization were carried. Then, the effect on the device of the FC thin film prepared between n-type silicon substrate and gold metal by the spin coating technique was reported. The ideality factor (n), barrier height (phi B) and series resistance (Rs) values of the prepared structure from the I-V data have been found at 1.08, 0.78eV and 240 at room temperature (300K), respectively. According to the Gaussian distribution of the barrier height obtained from the various temperature ranges (220-380K), the phi b0 and A* values from the ordinate intercept and the slope of the modified Richardson curve of ln versus 1/T plot which has been found to be 0.97eV and 114 A/cm(2)K(2), respectively. Results indicate that the high barrier height is achieved for the Au/FC/n-Si metal-organic layer-semiconductor diode as compared to the Au/n-Si metal-semiconductor (MS) diode

Optical characterization of Cu2ZnSnSe4-xSx nanocrystals thin film

WOS:000369581800021Cu2ZnSnSe4-xSx (CZTSeS) nanocrystals have been shown to be a potential application for sustainable thin-film solar cell devices. In this paper, we have presented the growth of nanocrystals CZTSeS and their thin films applications successfully prepared on soda-lime glass substrates by using spin coating techniques. The CZTSeS nanocrystals have been synthesized by hot-injection method. In-depth characterization has indicated that pure stoichiometric CZTSeS nanocrystals with an average particle size mostly distributed between 15 and 20 nm have been formed. We have analyzed the optical transmission and reflection spectra of nanocrystal CZTSeS thin film. Optical band gap E-g and absorption coefficient (a) of thin film have been determined by standard optical analysis and also several optical parameters such as refractive index (n), extinction coefficient (k), the Urbach energy (E-U) and real and imaginary parts of dielectric constant (epsilon) have been calculated. Detailed characterization data including X-ray diffraction, surface morphology, cross section analysis, optical transmittance and reflectance spectroscopy have been presented in order to use in the performance of single-junction solar devices. Optical measurements have showed a band gap of 1.51 eV, which is optimal for a single-junction solar device. (C) 2016 Elsevier B.V. All rights reserved.Selcuk University BAP officeSelcuk University [13401119]; TUBITAK (The Scientific and Technological Research Council of Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [214M366]This work is supported by Selcuk University BAP office with the research Project Number 13401119 and TUBITAK (The Scientific and Technological Research Council of Turkey) under project number 214M366