scholarly journals Study and Analysis of Simple and Precise of Contact Resistance Single-Transistor Extracting Method for Accurate Analytical Modeling of OTFTs Current-Voltage Characteristics: Application to Different Organic Semiconductors

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1448
Author(s):  
Noweir Ahmad Alghamdi

Contact resistance (Rc) characterizes the interface of source-drain electrodes/organic semiconductors and controls the injection efficiency of carriers in organic thin-film transistors (OTFTs). This research paper presents and assesses two methods for extracting the value of the contact resistance from the measured current-voltage characteristics of OTFTs made with various p-type organic semiconductors as active layers. These two methods are the transition voltage method (TVM) and the transfer line method (TLM). The obtained Rc values by the TVM method are in fair agreement with those obtained by TLM, with a maximum percentage of difference around 10%, demonstrating the accuracy of the used transition-voltage method. An analytical model was employed to calculate output characteristics in the linear regime of OTFTs made with various organic semiconductors using the contact resistance values obtained by the transition voltage method. The calculated results are in reasonably good agreement with the experimental ones of each fabricated device, which affirms the ability of the used model to characterize the charge transport correctly in these types of devices. It can be concluded that the used TVM method is not only an easy and practical method, but also a precise way for extracting Rc in OTFTs produced using different organic semiconductor materials.

2016 ◽  
Vol 845 ◽  
pp. 224-227 ◽  
Author(s):  
Danila Saranin ◽  
Marina Orlova ◽  
Sergey Didenko ◽  
Oleg Rabinovich ◽  
Andrey Kryukov

This article presents the results of research output voltage characteristics of solar cells on an organic basis with the use of P3HT: PCBM system. There were produced organic solar cells in a coating in air, current-voltage characteristics were measured. It was determined the characteristic influence of a substrate cleaning and annealing temperature of layers applied on fill factor and conversion efficiency.


1999 ◽  
Vol 607 ◽  
Author(s):  
S. Kato ◽  
T. Horikoshi ◽  
T. Ohkubo ◽  
T. Iida ◽  
Y. Takano

AbstractThe bulk crystal of silicon germanium was grown by vertical Bridgman method with germanium composition, x, varying from 0.6 to 1.0. The temperature dependent variation of the mobility is indicative of alloy scattering dominantly for the bulk wafer. Phosphorus was diffused in as-grown p-type bulk wafer at 850 °C to form pn-junction, and the diffusion coefficient of phosphorus was evaluated as a function of x. The diffusion behavior of phosphorus in silicon germanium is closely correlated with the germanium self-diffusion with changing x. For specimens with lower content x, P concentration profiles indicated “kink and tail” shape, while it was not observed for higher x. For current-voltage characteristics measurement, an ideality factor was obtained.


2021 ◽  
Author(s):  
Suman Yadav ◽  
Shivani Sharma ◽  
Satinder K Sharma ◽  
Chullikkattil P. Pradeep

Solution-processable organic semiconductors capable of functioning at low operating voltages (~5 V) are in demand for organic field-effect transistor (OFET) applications. Exploration of new classes of compounds as organic thin-film...


1985 ◽  
Vol 132 (2) ◽  
pp. 346-349 ◽  
Author(s):  
Nobuyoshi Koshida ◽  
Masahiro Nagasu ◽  
Takashi Sakusabe ◽  
Yuji Kiuchi

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Marcelo Rizzo Piton ◽  
Teemu Hakkarainen ◽  
Joonas Hilska ◽  
Eero Koivusalo ◽  
Donald Lupo ◽  
...  

AbstractThe performance of Ohmic contacts applied to semiconductor nanowires (NWs) is an important aspect for enabling their use in electronic or optoelectronic devices. Due to the small dimensions and specific surface orientation of NWs, the standard processing technology widely developed for planar heterostructures cannot be directly applied. Here, we report on the fabrication and optimization of Pt/Ti/Pt/Au Ohmic contacts for p-type GaAs nanowires grown by molecular beam epitaxy. The devices were characterized by current–voltage (IV) measurements. The linearity of the IV characteristics curves of individual nanowires was optimized by adjusting the layout of the contact metal layers, the surface treatment prior to metal evaporation, and post-processing thermal annealing. Our results reveal that the contact resistance is remarkably decreased when a Pt layer is deposited on the GaAs nanowire prior to the traditional Ti/Pt/Au multilayer layout used for p-type planar GaAs. These findings are explained by an improved quality of the metal-GaAs interface, which was evidenced by grazing incidence X-ray diffraction measurements in similar metallic thin films deposited on GaAs (110) substrates. In particular, we show that Ti exhibits low degree of crystallinity when deposited on GaAs (110) surface which directly affects the contact resistance of the NW devices. The deposition of a thin Pt layer on the NWs prior to Ti/Pt/Au results in a 95% decrease in the total electrical resistance of Be-doped GaAs NWs which is associated to the higher degree of crystallinity of Pt than Ti when deposited directly on GaAs (110).


2018 ◽  
Vol 83 (2) ◽  
pp. 20201 ◽  
Author(s):  
Yao Ni ◽  
Jianlin Zhou ◽  
Yuanyuan Hao ◽  
Hang Yu ◽  
Yanyun Li ◽  
...  

Organic thin film transistors (OTFTs) with silicon oxide (SiO2)/poly(4-vinylphenol) (PVP)/polymethylmethacrylate (PMMA) tri-layer structure (SPP) as dielectric layers have been fabricated. To verify the validity of such tri-layer structure, two different organic semiconductor materials such as p-type pentacene and n-type fluorinated copper phthalo–cyanine (F16CuPc) are both used for fabricating OTFTs. Comparing with the OTFTs even by using PMMA modification, the better interface quality existing between SPP dielectric and organic film leads a higher conductive efficiency for transport carriers in channel. And then the field effect carriers (hole in pentacene OTFTs and electron in F16CuPc OTFTs) mobilities are both increased obviously. Our results show the SPP dielectric structure can be widely used to improve performance of OTFTs.


2001 ◽  
Vol 680 ◽  
Author(s):  
Mi-Ran Park ◽  
Wayne A. Anderson

ABSTRACTStable and low-resistance Ohmic contacts are especially important for laser diodes where high current levels are required. Good contacts are especially difficult on p-type GaN which was the motivation for this study. The GaN was epitaxially grown on (0001) sapphire substrates by MOCVD. Resistivity of this layer was 3.5 Ohm-cm and thickness was 2 microns. After conventional cleaning followed by treatment in boiling HNO3: HCl (1:3), metallization was by thermally evaporating 40 nm Au / 60 nm Ni or 70 nm Au / 55 nm Pd. Heat treatment in O2 + N2 at various temperatures followed, with best results at 600 °C or 700 °C, respectively. Best values of the contact resistance were 1.8×10−4 Ohm-cm2 for Pd/Au and 2.65×10−4 Ohm-cm2 for Ni/Au contacts. After repetitive cycling from room temperature to 600 °C, the Ni contacts were very stable and more stable than the Pd contacts. X-ray photoelectron spectroscopy depth profiling showed the Ni contacts to be NiO followed by Au at the interface for the Ni/Au contacts whereas the Pd/Au contacts exhibited a Pd: Au solid solution. Some contacts were quenched in liquid nitrogen following sintering. These contacts were much more uniform under atomic force microscopy examination and gave a 3 times lower contact resistance with the Ni/Au design. Current-voltage-temperature analysis revealed that conduction was predominantly by thermionic field emission.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Biljana Simić ◽  
Dejan Nikolić ◽  
Koviljka Stanković ◽  
Ljubinko Timotijević ◽  
Srboljub Stanković

This study investigates the effects of neutron radiation onI-Vcharacteristics (current dependance on voltage) of commercial optoelectronic devices (silicon photodiodes, phototransistors, and solar panels). Current-voltage characteristics of the samples were measured at room temperature before and after irradiation. The diodes were irradiated using Am-Be neutron source with neutron emission of2.7×106 n/s. The results showed a decrease in photocurrent for all samples which could be due to the existence of neutron-induced displacement defects introduced into the semiconductor lattice. The process of annealing has also been observed. A comparative analysis of measurement results has been performed in order to determine the reliability of optoelectronic devices in radiation environments.


1992 ◽  
Vol 281 ◽  
Author(s):  
C. Piskoti ◽  
B. Mykolajenko ◽  
M. Vaziri

ABSTRACTTo study the formation of ohmic contacts, several metals have been deposited on p-types ZnTe and ZnSe epitaxial layers. The metals were deposited on the layers either by simple evaporation or by electroplating. The current-voltage characteristics associated with each metal contact were measured. The preliminary results of these measurements indicate that electroplating is a better technique for making ohmic contact to these layers.


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