• Journal of IKEEE
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• v.26 no.4
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• pp.705-709
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• 2022

The effect of the annealing temperature of the poly(vinylidene fluoride-trifluoroethylene)(P(VDF-TrFE)) solid electrolyte layer on the electrical properties of the P(VDF-TrFE)-based memristor was analyzed. In morphological analyses, the P(VDF-TrFE) thin film with 200℃ annealing temperature (200P(VDF-TrFE)) was shown to have surface roughness ≈5 times larger and thickness ≈20% smaller than that with 100℃ annealing temperature (100P(VDF-TrFE)). Compared to the 100P(VDF-TrFE) memristor (M100), the set voltage of the 200P(VDF-TrFE) memristor (M200) decreased by ≈50% and the magnitude of its reset voltage increased by ≈30%. Moreover, M200 was found to have better memory retention characteristics than M100. These differences were attributed to relatively strong local electric fields inside M200 compared to M100. This study suggests the importance of the annealing temperature in polymer memristors.

• Composites Research
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• v.28 no.3
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• pp.75-80
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• 2015

Poly(vinylidene fluoride-trifluoroethylene; P(VDF-TrFE)) is one of the most promising electroactive polymers with numerous application potentials in many fields of industry. Because of its good electro-mechanical properties P(VDF-TrFE) has been used for a number of sensors and actuators and also can be used for monitoring composite structure behaviors as a sensor. Three different ways (Electrical poling, annealing-cooling, and pressing) to enhance ${\beta}$-phase of P(VDF-TrFE) film were carried out. A microscopic analysis was conducted using X-ray diffraction to investigate the effect of such treatments on piezoelectric properties of P(VDF-TrFE) film. From the results, poling, annealing-cooling, and pressing were all effective to enhance ${\beta}$ crystallinity of P(VDF-TrFE) film and the maximum increase rate was 62.80% from 45.29% of the control group.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.115-116
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• 2008

The ferroelectric vinylidene fluoride-trifluoroethylene ($VF_2$-TrFE) and $Al_2O_3$ passivation layer for the Metal/Insulator/Ferroelectric/Semiconductor (MIFS) structure were deposited using spin coating and remote plasma atomic layer deposition (RPALD), respectively. A 2.5 ~ 3 wt % diluted solution of purified vinylidene fluoride-trifluoroethylene ($VF_2$: TrFE=70:30) in a DMF solution were prepared and deposited on silicon wafer at a optimized spin speed. After annealing in a vacuum ambient at 150 ~ $200^{\circ}C$ for 60 min, upper insulator layer were deposited at temperature ranging from 100 ~ $150^{\circ}C$ by RPALD. We described electrical and structural properties of MIFS fabricated by spin coating and RPALD methods.

• Polymer(Korea)
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• v.31 no.4
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• pp.343-348
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• 2007

In this study, terpolymer of vinylidene fluoride (VDF), trifluoroethylene (TrFE), and chlorotrifluoroethylene (CTFE) were prepared by suspension polymerization using di-tertiary-butyl peroxide (DTBP) as an initiator. The structural characteristics including microstructure and chain conformation of the polymers have been carefully elucidated as a function of the chemical composition using NMR, FT-IR. The intensity of absorption bands of the $\beta$-phase gradually decreases and the $\gamma$-phase increases with the increment of CTFE mol%. The analysis results of DSC shows that the Curie phase transition temperature ($T_c$) of the terpolymer gradually shifts to ambient temperature and trace becomes smaller and broader with the increment of CTFE mol%. Also, activation energies of the samples were calculated by Freeman-Carroll method.

• Journal of IKEEE
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• v.25 no.2
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• pp.322-329
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• 2021

In this study, a method for improving the light extraction efficiency of organic light emitting diodes was presented using the polymer Poly(vinylidenefluoride-co-trifluoroethylene) [P(VDF-TrFE)] having an island surface structure after annealing. Polydimethylsiloxane (PDMS) imprinted on the island-structured P(VDF-TrFE) surface has a spike structure, which improves the external light extraction efficiency aroud 20%. It was confirmed that the produced film showed a low haze characteristic of 8.2, and the Current and external quantum efficiency could be improved without pixel blur due to the excellent transmittance of 93.4%.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.105-109
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• 2002

vinylidene fluoride(VDF)와 trifluoroethylene(TrFE)의 공중합체 인 P(VDF/TrFE)는 전기활성을 갖는 강유전성 결정이므로 압전성 및 초전성 재료로 PVDF와 더불어 널리 사용되고 있다. 그러나 P(VDF/TrFE)는 어떤 온도 이상에서는 all-trans conformation을 하는 강유전 결정상이 전기적으로 불활성으로 되면서 PVDP의 $\alpha$-결정의 사슬배좌(trans-gauche)와 유사한 상유전 결정상으로 전이하는 상승 Curie 전이 온도 (T$^{\uparrow}$ $_{c}$ )가 존재하기 때문에 P(VDF/TrFF)의 압전재료로서의 적용온도 범위가 넓지 못하다는 단점이 있다. (중략)

• Composites Research
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• v.30 no.2
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• pp.126-131
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• 2017

For structural health monitoring of a complex shaped structure a new sensor that can compensate for the drawbacks of the current sensors such as brittleness is needed and the sensor should be highly flexible and durable. In this study a textile sensor made of polyvinylidene fluoride trifluoroethylene (PVDF-TrFE) which is a type of electroactive polymer was fabricated. And the textile sensors were applied to a complex shaped structure (an egg-box panel made of carbon/epoxy composite) for checking their feasibility of structural health monitoring. To correlate the collapse response with failure mechanisms of the structure the multiply-interrupted compressive test was carried out. During the test, the textile sensors succeeded to prove their applicability for damage detection (crack initiation) by generating electric voltages (0.05 V-0.25 V) in the real time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.388-388
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• 2010

In this study, Ferroelectric vinylidene fluoride-trifluoroethylene (VF2-TrFE) copolymer films were directly deposited on degenerated Si (n+, $0.002\;{\Omega}{\cdot}cm$) using by spin coating method. A 1~5 wt% diluted solution of purified vinylidene fluoride-trifluoroethylene (VF2:TrFE = 70:30) in a dimethylformamide (DMF) solvent were prepared and deposited on silicon wafers at a spin rate of 2000 ~ 4000 rpm for 2 ~ 30 seconds. After annealing in a vacuum ambient at 100 ~ $200^{\circ}C$ for 60 min, upper aluminum electrodes were deposited by vacuum evaporation for electrical measurement. X-ray diffraction results showed that the VF2-TrFE films on Si substrates had $\beta$-phase of copolymer structures. The capacitance on highly doped Si wafer showed hysteresis behavior like a butterfly shape and this result indicates clearly that the copolymer films have ferroelectric properties. The typical measured remnant polarization ($P_r$) and coercive filed ($E_c$) values were about $5.7\;{\mu}C/cm^2$ and 710 kV/em, respectively, in an applied electric field of ${\pm}$ 1.5 MV/em. The gate leakage current densities measured at room temperature was less than $7{\times}10^{-7}\; A/cm^2$ under a field of 1 MV/cm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.8
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• pp.698-703
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• 2009

We report the studies on the structrural properties of Langmuir Blodgett (LB) films fabricated from the copolymer of vinylidenefluoride (VDF) with trifluoroethylene(TrFE). The formation of nanomesas induced by thermal annealing at $135\;^{\circ}C$ for 1 hour was investigated with the atomic force microscope (AFM) and the X-ray diffractometer (XRD). From the result of surface morphology change in 30 monolayer LB film, we find that the annealing treatment on the P(VDF-TrFE) LB film result in the plastic deformation of crystalline polymer. The ${\beta}$ phase crytalline structure in annealed LB film was clearly confirmed from the XRD peak at $19.7^{\circ}$.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.232-233
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• 2001

2차 비선형광학 물질이 높은 응용성을 갖기 위해서는 큰 2차 비선형광학 계수뿐만 아니라 넓은 파장 영역에 걸친 투명성을 가지고 있어야 한다. vinylidene fluoride(VDF)와 trifluoroethylene(TrFE)가 공중합된 f(VDf-TrFE) 공중합체는 이러한 조건을 갖추고 있는 강유전성 물질이다. 우리는 몰비율이 72：28인 P(VDF-TrFE)을 ITO기판위에 casting하고 corona 극화한 뒤, 두 개의 입력 파장(1064nm, 532nm)에 대한 2차 조화파 발생 실험을 실시하고 Herman과 Hayden의 마커무의 식을 이용하여 2차 비선형 광학 계수를 측정하였다. (중략)