Analysis of inhomogeneous device parameters using current-voltage characteristics of identically prepared lateral Schottky structures

TUGLUOGLU, NIHAT/0000-0001-9428-4347; KORALAY, HALUK/0000-0001-7893-344XWOS: 000374681400006We have identically fabricated 50 dots of Au/n-Si/Al Schottky structures and investigated the mean values of diode parameters from current-to-voltage (I-V) characteristics at 300 K. The values of diode parameters are determined from I-V characteristics, and Cheung and the modified Norde functions are varied from diode to diode although the Schottky structures are identically fabricated. The experimental values of ideality factor (n) and barrier height (Phi(B)) for 50 dots of the Au/n-Si/Al Schottky structures have ranged from 1.048 to 1.695 and from 0.708 to 0.807 eV, respectively. The interface state densities (N-ss) are approximately obtained from 2 x 10(13) to 2 x 10(11) eV(-1) cm(-2) in the energy range from E-c - 0.45 to E-c - 0.75 eV, respectively. These findings can be referred to lateral barrier inhomogeneities of Schottky diodes. The distributions of all calculated parameters have been fitted by means of Gaussian function. The mean n and Phi(B) values have been found to be 1.316 +/- 0.213 and 0.758 +/- 0.030 eV, respectively. Furthermore, the value of lateral homogenous barrier height for 50 dots of Schottky structures is determined as 0.802 eV from the linear relationship between n and Phi(B).Gazi University BAP OfficeGazi University [05/2013-06]This work was supported by Gazi University BAP Office (Project No: 05/2013-06)

Analysis of electrical properties of Al/p-Si Schottky contacts with and without rubrene layer

TUGLUOGLU, NIHAT/0000-0001-9428-4347WOS: 000318318000003The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of Al/p-Si diode without and with rubrene layer fabricated by spin coating method have been investigated. From analyzing the I-V measurements for Al/p-Si diode, the basic device parameters such as barrier height, ideality factor and series resistance were extracted and then compared with the value which calculated from the I-V measurements for Al/rubrene/p-Si diode at room temperature. Also, the barrier height, built-in potential, concentration of ionized donors, and some other parameters of diode were found using C-V measurements. The barrier height values of 0.649 and 0.771 eV and ideality factor values of 1.22 and 1.51 were calculated using I-V measurements for diodes without and with rubrene layer, respectively. It has been seen that the rubrene layer raises the barrier height value of the device since this layer generates the physical barrier between p-Si and Al. By using C-V measurement of the Al/rubrene/p-Si diode, the barrier height value has been found as 0.820 eV. The energy distribution of the interface state density of device with rubrene layer determined from I-V characteristics increases exponentially with bias from 8.72 x 10(9) to 2.43 x 10(11) cm(-2) eV(-1). (C) 2013 Elsevier B.V. All rights reserved.Giresun University BAP officeGiresun University [FEN-BAP-A-160512-26]; Giresun University BAP officeGiresun UniversityThis work was partially supported by Giresun University BAP office with the research project number of FEN-BAP-A-160512-26. One of the others (B. Baris) is greatfull for financial assistance provided by Giresun University BAP office

Some optical properties of melanin thick film

International Congress on Semiconductor Materials and Devices (ICSMD) -- AUG 17-19, 2017 -- Selcuk Univ, Konya, TURKEYWOS: 000495858400024The melanin obtained from brown-black sheep wool was prepared in the form of thick film by using drop casting method on the soda-lime glass substrate. The optical properties of the melanin thick film have been investigated by means of the optical measurements. It was observed that the thick film showed high transmittance value nearly up to 84 % in the IR spectral region and it showed very high absorbance in both UV and visible regions. From standard optical analysis, it was observed that melanin thick film had the properties of the semiconductors with indirect band gap, and the band gap energy value was found as 1.24 eV. Also, it was seen that calculated refractive index of the melanin thick film varies between 1.37 and 1.63 throughout the spectral region considered. (C) 2019 Elsevier Ltd. All rights reserved

Electrical Characterization of Au/Fluorene-Carbazole (FC)/p-Si Schottky Barrier Diodes

International Semiconductor Science and Technology Conference (ISSTC) -- MAY 11-13, 2015 -- Kusadasi, TURKEYTUGLUOGLU, NIHAT/0000-0001-9428-4347WOS: 000373069200005The Fluorene-Carbazole (FC) was synthesized by Suziki method in this study. The organic semiconductor is prepared on p-type Si substrate by spin coating method. We have produced Au/FC/p-Si Schottky diodes. We have investigated the current-voltage characteristics over temperature range between 200 and 350 K. The measured current-voltage (I-V) characteristics of device have demonstrated a good rectification behaviour at all temperatures. The parameters such as the ideality factor (n), barrier height (Phi(B)) and series resistance (R-S) were determined from the experimental data using standard current-voltage analysis method. At T=200 K, we have found the values of the n and Phi(B) as 2.78 and 0.491 eV respectively. On the other hand, their values were found as n=1.86 and Phi(B)=0.779 eV at T=350 K. The values of R-S are calculated using Cheung and Cheung functions between 200 K and 350 K. The H(I)-I plot of Cheung and Cheung method shows RS of 1823.23 Omega for 200 K and value of 952.6 Omega for 350 K. (C) 2015 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of Conference Committee Members of International Semiconductor Science and Technology Conference 2015 (ISSTC 2015).Kavasoglu Pazarlama Ticaret Ltd Sti, Kontek Muhendislik Otomasyon Danismanlik San Tic Ltd Sti, Tekno Tip Analitik Sistemler Ltd Sti, Yildirim Elektronik, Gediz Univ Teknoloji Transfer Ofisi, Haml

Investigation of optical and dispersion parameters of electrospinning grown activated carbon nanofiber (ACNF) layer

Waisi, Basma/0000-0001-7842-5541WOS: 000427336700003Activated carbon nanofiber (ACNF) layers are prepared by electrospinning method. We have investigated the optical properties of ACNF layer using UV-vis-NIR spectrophotometer. The optical constants such as refractive index, extinction coefficient and dielectric constants were evaluated using reflectance and transmittance spectra for ACNF layer. The optical energy gap of ACNF layer was determined as 1.07 eV. The refractive index dispersion of ACNF layer was analyzed by using the single oscillator model proposed by Wemple and DiDomenico. The dispersion parameters such as oscillator energy and dispersion energy values of ACNF layer were determined. Several dispersion parameters such as optical dielectric constant at higher frequency, lattice dielectric constant, oscillator average wavelength, oscillator average strength and the ratio of carrier concentration to the effective mass were also determined by analysis of refractive index dispersion. Furthermore, the optical conductivity of ACNF layer was evaluated from the analysis of optical dielectric constants