scholarly journals Negative series resistance and photo-response properties of Au/PPY-MWCNTs composite /TiO2/Al2O3/n-Si/Al photodiode

Author(s):  
A. Ashery ◽  
A. E. H. Gaballah ◽  
Emad M. Ahmed

Abstract The paper addresses a novel approach concerning the appearance of negative series resistance (Rs) at high frequencies for both temperatures and voltages. Most of the previous studies have focused on the relationship between voltage and current (I - V) to determine the value of Rs using several methods. By measuring capacitance and conductance as a function of voltage, we were able to develop a systematic analysis of series resistance. At high frequencies of 2×107, 107 Hz, Rs has negative values however, at frequency 106Hz it takes both positive and negative values, whilst from (105 - 10) Hz it has positive values. Here in this article, we synthesized Au/PPY-MWCNTs/TiO2/Al2O3/n-Si/Al structure which can be used in a variety of applications such as supercapacitors, and diodes. We investigated the electrical properties such as ideality factor (n), barrier height (фb), series resistance using several approaches such as conventional, Chueng, and Nord methods. The structure has shown rectification with a good response to daylight illumination. The structure response to daylight illumination indicates that photodiodes have the potential to be used as solar detectors.

NANO ◽  
2014 ◽  
Vol 09 (06) ◽  
pp. 1450062 ◽  
Author(s):  
N. PADMA ◽  
MANORANJAN GHOSH ◽  
SHASHWATI SEN ◽  
R. TEWARI

Nanocomposites of n-type Zinc Oxide ( ZnO ) and p-type copper phthalocyanine ( CuPc ) were synthesized using solution route and the electrical properties of heterojunctions of ZnO and CuPc in the nanocomposite film was studied. For comparison, electrical properties of bilayer heterojunction devices using ZnO nanostructure drop cast film and thermally evaporated CuPc were also studied. Rectification ratio (RR) of about 28 and 5.5 was obtained at 4 V for devices with nanocomposite film and bilayer heterojunctions indicating improved formation of p–n junction characteristics for nanocomposite films. Values of ideality factor, barrier height at the p–n junction interface and series resistance were estimated using different methods like semilog plots, Cheung and Norde's methods. Ideality factor estimated from semilog plots and Cheung's methods were found to be higher than unity indicating deviation from ideal diode behavior. Barrier height estimated from different methods was about 0.7 eV. Series resistance measured using Cheung and Norde's methods were found to be about 92 KΩ and 21 KΩ, respectively. Bilayer heterojunction devices exhibited much higher series resistance, ideality factor and barrier height as estimated using all the above-mentioned methods as compared to the devices with nanocomposite film. The above results indicate intimate mixing and improved interface between ZnO and CuPc in the in situ synthesized nanocomposite film thereby offering improved p–n junction characteristics.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Reşit Özmenteş ◽  
Cabir Temirci

AbstractIn this study, CuO/n-Si/Al heterojunction contacts were fabricated by thermal evaporation technique. Electrical characteristics of the samples were investigated with the current-voltage (I-V), capacitance-voltage/frequency (C-V/f), and conductance-voltage (G/V) measurements at room temperature. Also, Cu/n-Si/Al Schottky contact was produced as a reference sample to investigate the electrical properties of the samples. The values of ideality factor (n), barrier height (Φb) and series resistance (Rs) of the samples were calculated from the forward bias current-voltage (I-V) and reverse bias capacitance-voltage (C-V) characteristics. Also, for checking the consistency of the results, Cheung and Norde functions were used. The experimental result values of CuO/n-Si contact were compared with the values of the reference Cu/n-Si Schottky diode. It was observed that the values of the ideality factor and barrier height of the CuO/n-Si heterojunction were higher than those of the Cu/n-Si Schottky contact, while the series resistance was lower. Also, it has been observed that the value of capacitance decreased with increasing frequency and after a certain value of frequency it was almost constant. The ideality factor of CuO/n-Si/Al heterostructure is about 2.40 and so, it is not close to the ideal behavior.


2009 ◽  
Vol 609 ◽  
pp. 195-199
Author(s):  
A. Keffous ◽  
M. Kechouane ◽  
Tahar Kerdja ◽  
Y. Belkacem ◽  
K. Bourenane ◽  
...  

In this paper we present the study of a Schottky diode gas sensing by using porous SiC films with palladium as a catalytic metal. The Schottky diodes were used for the first time for hydrocarbon (C2H6) gas sensing. The properties of the porous SiC films formed by electrochemical method were investigated by scanning electron microscopy (SEM). The electrical measurements were made at room temperature (295 K) in different ambient. The effect of the porous surface structure was investigated by evaluating electrical parameters such as the ideality factor (n), barrier height (Bp) and series resistance (Rs). The porous layer significantly affects the electrical properties of the Schottky diodes. Analysis of current-voltage (I-V) characteristics showed that the forward current might be described by a classical thermal emission theory. The ideality factor determined by the I–V characteristics was found to be dependent on the SiC thickness. For a thinner SiC layer (0.16 µm), the electrical parameters n was found around 1.135, 0.7041 eV for a barrier height and 45  for a series resistance, but for a thicker one (1.6 µm) n, Bp and Rs were 1.368, 0.7756 eV and 130 , respectively. The low value of the series resistance obtained using Cheung’s method clearly indicated the high performance of the Schottky diode for thinner SiC layer. This effect showed the uniformity of the SiC layer. Finally, sensitivity around 66 % and selectivity of the sensors were reached by using the PSC layer at low voltages below 0.5 Volt.


Author(s):  
Sabuhi Ganiyev ◽  
M. Azim Khairi ◽  
D. Ahmad Fauzi ◽  
Yusof Abdullah ◽  
N.F. Hasbullah

In this paper the effects of high energy (3.0 MeV) electrons irradiation over a dose ranges from 6 to 15 MGy at elevated temperatures 298 to 448 K on the current-voltage characteristics of 4H-SiC Schottky diodes were investigated. The experiment results show that after irradiation with 3.0 MeV forward bias current of the tested diodes decreased, while reverse bias current increased. The degradation of ideality factor, n, saturation current, Is, and barrier height, Phib, were not noticeable after the irradiation. However, the series resistance, Rs, has increased significantly with increasing radiation dose. In addition, temperature dependence current-voltage measurements, were conducted for temperature in the range of 298 to 448 K. The Schottky barrier height, saturation current, and series resistance, are found to be temperature dependent, while ideality factor remained constant. DOI: 10.21883/FTP.2017.12.45193.8646


2008 ◽  
Vol 600-603 ◽  
pp. 1341-1344 ◽  
Author(s):  
Fabrizio Roccaforte ◽  
Ferdinando Iucolano ◽  
Filippo Giannazzo ◽  
Salvatore di Franco ◽  
Valeria Puglisi ◽  
...  

In this work, the electrical properties of Pt/GaN Schottky contacts were studied. The temperature dependence of the barrier height and ideality factor, and the low experimental value of the Richardson’s constant, were discussed considering the formation of an inhomogenous Schottky barrier. Local current-voltage measurements on Pt/GaN contact, performed with a conductive atomic force microscope, demonstrated a Gaussian distribution of the local barrier height values and allowed to monitor the degree of inhomogeneity of the barrier. The presence of defects, terminating on the bare GaN surface, was correlated with the electrical behavior of the inhomogeneous barrier.


2020 ◽  
Vol 34 (10) ◽  
pp. 2050095
Author(s):  
Durmuş Ali Aldemir

Zr/p-Si Schottky diode was fabricated by DC magnetic sputtering of Zr on p-Si. Zr rectifying contact gave a zero bias barrier height of 0.73 eV and an ideality factor of 1.33 by current–voltage measurement. The experimental zero bias barrier height was higher than the value predicted by metal-induced gap states (MIGSs) and electronegativity theory. The forward bias current was limited by high series resistance. The series resistance value of 9840 [Formula: see text] was determined from Cheung functions. High value of the series resistance was ascribed to low quality ohmic contact. In addition to Cheung functions, important contact parameters such as barrier height and series resistance were calculated by using modified Norde method. Re-evaluation of modified Norde functions was realized in the direction of the method proposed by Lien et al. [IEEE Trans. Electron Devices 31 (1984) 1502]. From the method, the series resistance and ideality factor values were found to be as 41.49 [Formula: see text] and 2.08, respectively. The capacitance–voltage characteristics of the diode were measured as a function of frequency. For a wide range of applied frequency, the contact parameters calculated from [Formula: see text]–[Formula: see text] curves did not exhibit frequency dependence. The barrier height value of 0.71 eV which was in close agreement with the value of zero bias barrier height was calculated from [Formula: see text]–[Formula: see text] plot at 1 MHz. The values of acceptor concentration obtained from [Formula: see text]–[Formula: see text] curves showed consistency with actual acceptor concentration of p-Si.


2011 ◽  
Vol 1406 ◽  
Author(s):  
Cleber A. Amorim ◽  
Olivia M. Berengue ◽  
Luana Araújo ◽  
Edson R. Leite ◽  
Adenilson J. Chiquito

ABSTRACTIn this work, we studied metal/SnO2 junctions using transport properties. Parameters such as barrier height, ideality factor and series resistance were estimated at different temperatures. Schottky barrier height showed a small deviation of the theoretical value mainly because the barrier was considered fixed as described by ideal thermionic emission-diffusion model. These deviations have been explained by assuming the presence of barrier height inhomogeneities. Such assumption can also explain the high ideality factor as well as the Schottky barrier height and ideality factor dependence on temperature.


Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 283
Author(s):  
Dong-Hyeon Kim ◽  
Michael A. Schweitz ◽  
Sang-Mo Koo

It is shown in this work that annealing of Schottky barrier diodes (SBDs) in the form of Ni/AlN/SiC heterojunction devices in an atmosphere of nitrogen and oxygen leads to a significant improvement in the electrical properties of the structures. Compared to the non-annealed device, the on/off ratio of the annealed SBD devices increased by approximately 100 times. The ideality factor, derived from the current-voltage (IV) characterization, decreased by a factor of ~5.1 after annealing, whereas the barrier height increased from ~0.52 to 0.71 eV. The bonding structure of the AlN layer was characterized by X-ray photoelectron spectroscopy. Examination of the N 1 s and O 1 s peaks provided direct indication of the most prevalent chemical bonding states of the elements.


Author(s):  
R. Padma ◽  
V. Rajagopal Reddy

The electrical properties of the Ir/Ru Schottky contacts on n-InGaN have been investigated by current-voltage (I-V), capacitance-voltage (C-V), capacitance-frequency (C-f) and conductance-frequency (G-f) measurements. The obtained mean barrier height and ideality factor from I-V are 0.61 eV and 1.89. The built-in potential, doping concentration and barrier height values are also estimated from the C-V measurements and the corresponding values are 0.62 V, 1.20x1017 cm-3 and 0.79 eV, respectively. The interface state density (NSS) obtained from forward bias I-V characteristics by considering the series resistance (RS) values are lower without considering the series resistance (RS). Furthermore, the interface state density (NSS) and relaxation time (tau) are also calculated from the experimental C-f and G-f measurements. The NSS values obtained from the I-V characteristics are almost three orders higher than the NSS values obtained from the C-f and G-f measurements. The experimental results depict that NSS and tau are decreased with bias voltage. The frequency dependence of the series resistance (RS) is attributed to the particular distribution density of interface states. DOI: 10.21883/FTP.2017.12.45189.8340


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