EFFECT OF GATE INSULATOR ON THE PERFORMANCE OF COPPER PHTHALOCYANINE-BASED ORGANIC THIN FILM TRANSISTORS

2011 ◽  
Vol 10 (04n05) ◽  
pp. 745-748
Author(s):  
N. PADMA ◽  
SHASWATI SEN ◽  
A. K. CHAUHAN ◽  
D. K. ASWAL ◽  
S. K. GUPTA ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Field Effect ◽  
Gate Dielectric ◽  
Copper Phthalocyanine ◽  
Field Effect Transistors ◽  
Drain Current ◽  
Dielectric Constants ◽  
Gate Insulator ◽  
Operating Voltage ◽  
Organic Thin Film

Effect of the gate dielectric on the performance of Copper phthalocyanine (CuPc) based top contact organic field effect transistors (OFET) has been studied using thermally grown SiO2 and sputtered HfO x films with dielectric constants of 3.9 and 12.5 respectively. Operating voltages of the devices on SiO2 and HfO x were found to be 10–50 V and 2–3 V, respectively. The lower operating voltage for HfO x is attributed to the higher dielectric constant. Devices on SiO2 and HfO x were found to have field effect mobilities of 0.01 and 3.5 × 10-3 cm2/Vs and drain current modulation of 103 and 102, respectively. Scanning Electron Microscopy showed widely scattered nanowires on HfO x and densely packed nanofibers on SiO2 . X-ray diffraction studies showed better crystallinity of films on SiO2 . The results show that operating voltage of devices can be reduced by using higher dielectric constant material while mobility and FET characteristics depend on structure of CuPc that in turn is influenced by the dielectric.

Characteristics of Gamma–Ray Irradiated Pentacene Organic Thin Film Field Effect Transistors

2011 ◽  
Vol 306-307 ◽  
pp. 185-192 ◽  
Author(s):  
Hiroaki Yano ◽  
Li Cai ◽  
Toshio Hirao ◽  
Zong Fan Duan ◽  
Yutaro Takayanagi ◽  
...  
Keyword(s):  
Field Effect ◽  
Gamma Ray ◽  
Field Effect Transistors ◽  
Uv Light ◽  
Drain Current ◽  
Gate Insulator ◽  
Organic Thin Film ◽  
Drain Voltage ◽  
Continuous Increase ◽  
Uv Light Irradiation

P-channel pentacene field effect transistorswith a Si/SiO2/pentacene/Au structure were fabricated, and were gamma-ray irradiated with a Co60source. The changes of the drain current IDvs. source/drain voltage VSD(ID- VSD) characteristics were measured after every 200 Gy in silicon (GySi) irradiations up to the total dose of 1200 GySi. The drain current IDcontinuously decreased to less than 10 % of that before irradiation after 1200 GySiirradiation. The threshold voltage Vthcontinuously decreased up to 800 GySi, started to saturate above 800 GySi,and recovered above1000 GySi. The mobility m continued to decrease up to 1200 GySi. Those behaviors were explained by accumulation of positive trapped charge within the gate insulator SiO2near the interface, continuous increase of interface traps near the interface between the SiO2and pentacene, and build up of electrons in the channel regions. These behaviors were discussed in comparisons with previously reported results on ultraviolet (UV) light irradiation experiments on similarly structured pentacene-based transistors.

scholarly journals USING PERCOLATIVE CRYSTALLINE 0.3 CUO/PVDF NANOCOMPOSITE GATE DIELECTRIC FOR FABRICATING HIGH-EFFECT MOBILITY THIN FILM TRANSISTOR OPERATING AT LOW VOLTAGE

2021 ◽  
Vol 9 (11) ◽  
pp. 1095-1101
Author(s):  
Debabrata Bhadra ◽  
Keyword(s):  
Thin Film ◽  
Field Effect ◽  
Gate Dielectric ◽  
Low Voltage ◽  
Field Effect Transistors ◽  
Thin Film Transistor ◽  
Dielectric Constants ◽  
Gate Insulator ◽  
Electrical Characteristics ◽  
Capacitance Density

Thin-film transistor (TFT) with various layers of crystalline Poly-vinylidene fluoride (PVDF)/CuO percolative nanocomposites based on Anthracene as a gate dielectric insulator have been fabricated. A device with excellent electrical characteristics at low operating voltages (<1V) has been designed. Different layers (L) of the film were also prepared to achieve the best optimization of ideal gate insulator with various static dielectric constants (εr). Capacitance density, leakage current at 1V gate voltage and electrical characteristics of OFETs with a single and multi layer films have been investigated. This device was showed highest field effect mobility of 2.27 cm2/Vs, a threshold voltage of -1.6V, an exceptionally low sub threshold slope of 380 mV/decade and an on/off ratio of 106. Such a High-ε three layered (3L) PVDF/CuO gate dielectric appears to be highly promising candidates for organic non-volatile memory, sensor and field-effect transistors (FETs).

Degradation of organic field-effect transistors made of pentacene

2004 ◽  
Vol 19 (7) ◽  
pp. 1999-2002 ◽  
Author(s):  
Ch. Pannemann ◽  
T. Diekmann ◽  
U. Hilleringmann
Keyword(s):  
Charge Carrier ◽  
Threshold Voltage ◽  
Field Effect ◽  
Gate Dielectric ◽  
Field Effect Transistors ◽  
Ambient Air ◽  
Organic Field Effect Transistors ◽  
Organic Thin Film ◽  
Field Effect Mobility ◽  
Semiconducting Material

This article reports degradation experiments on organic thin film transistors using the small organic molecule pentacene as the semiconducting material. Starting with degradation inert p-type silicon wafers as the substrate and SiO2 as the gate dielectric, we show the influence of temperature and exposure to ambient air on the charge carrier field-effect mobility, on-off-ratio, and threshold-voltage. The devices were found to have unambiguously degraded over 3 orders of magnitude in maximum on-current and charge carrier field-effect mobility, but they still operated after a period of 9 months in ambient air conditions. A thermal treatment was carried out in vacuum conditions and revealed a degradation of the charge carrier field-effect mobility, maximum on-current, and threshold voltage.

scholarly journals Graphene Oxide/Polystyrene Bilayer Gate Dielectrics for Low-Voltage Organic Field-Effect Transistors

2018 ◽  
Vol 9 (1) ◽  
pp. 2 ◽  
Author(s):  
Sooji Nam ◽  
Yong Jeong ◽  
Joo Kim ◽  
Hansol Yang ◽  
Jaeyoung Jang
Keyword(s):  
Graphene Oxide ◽  
Field Effect ◽  
High Performance ◽  
Gate Dielectric ◽  
Low Voltage ◽  
Field Effect Transistors ◽  
High Mobility ◽  
Operating Voltage ◽  
Organic Field Effect Transistors ◽  
Gate Leakage

Here, we report on the use of a graphene oxide (GO)/polystyrene (PS) bilayer as a gate dielectric for low-voltage organic field-effect transistors (OFETs). The hydrophilic functional groups of GO cause surface trapping and high gate leakage, which can be overcome by introducing a layer of PS—a hydrophobic polymer—onto the top surface of GO. The GO/PS gate dielectric shows reduced surface roughness and gate leakage while maintaining a high capacitance of 37.8 nF cm−2. The resulting OFETs show high-performance operation with a high mobility of 1.05 cm2 V−1 s−1 within a low operating voltage of −5 V.

Study of Solid/liquid Interfaces in Organic Field-effect Transistors with Ionic Liquids

2009 ◽  
Vol 1154 ◽  
Author(s):  
Shimpei Ono ◽  
Kazumoto Miwa ◽  
Shiro Seki ◽  
Jun Takeya
Keyword(s):  
Ionic Liquid ◽  
Field Effect ◽  
Carrier Mobility ◽  
Gate Dielectric ◽  
Field Effect Transistors ◽  
High Mobility ◽  
Double Layers ◽  
Liquid Interfaces ◽  
Organic Thin Film ◽  
Solid Liquid

AbstractWe report high-mobility rubrene single-crystal field-effect transistors with ionic-liquid electrolytes used for gate dielectric layers. As the result of fast ionic diffusion to form electric double layers, their capacitances remain more than 1.0 μF/cm2 even at 0.1 MHz. With high carrier mobility of 9.5 cm2/Vs in the rubrene crystal, pronounced current amplification is achieved at the gate voltage of only 0.2 V, which is two orders of magnitude smaller than that necessary for organic thin-film transistors with dielectric gate insulators. The results demonstrate that the ionic-liquid/organic semiconductor interfaces are suited to realize low-power and fast-switching field-effect transistors without sacrificing carrier mobility in forming the solid/liquid interfaces.

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