• Macromolecular Research
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• v.12 no.1
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• pp.94-99
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• 2004

We have performed Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) studies on blends of poly(vinyl phenol) (PVPh) with poly(n-alkylene 2,6-naphthalates) containing alkylene units of different lengths. The results indicate that each poly(ethylene 2,6-naphthalate) (PEN) and poly(trimethylene 2,6-naphthalate) (PTN) blend with PVPh is immiscible or partially miscible, but blends of poly(butylene 2,6-naphthalate) (PBN) with PVPh are miscible over the whole range of compositions in the amorphous state. FTIR spectroscopic analysis confirmed that significant degree of intermolecular hydrogen bonding occurs between the PBN ester carbonyl groups and the PVPh hydroxyl groups. The large difference in the degree of mixing in these blend systems is described in terms of the effect that chain mobility has on the accessibility of the ester carbonyl functional groups toward the hydroxyl groups of PVPh, which in turn impacts the miscibility of these blends.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1572-1575
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• 2005

Poly(vinyl phenol)(PVP)/$TiO_2$ nanocomposite the films have been prepared incorporating metal alkoxide with vinyl polymer to obtain high dielectric constant gate insulating material for a organic thin film transistor. The surface composition, the morphology, and the thermal and electrical properties of the hybrid nanocomposite films were observed by ESCA, scanning electron microscopy (SEM), atomic force microscopy(AFM), and thermogravimetric analysis (TGA). Thin hybrid films exhibit much higher dielectric constants (7.79 at 40wt% metal alkoxide).

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1305-1307
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• 2009

We have investigated the new modification of poly (vinyl phenol) (PVP) for low hysteresis organic thin film transistors (OTFTs). In order to suppression of hysteresis phenomenon, synthesized various backbone structure polymeric gate dielectric. The modified polymeric dielectric was synthesized by inducing ringshape phenol backbone structure instead of conventional chain. We could be observed that relieved hysteresis and excellent air stability from ring-shape phenol backbone structure.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.289.1-289.1
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• 2014

In this study, we made a organic thin film device in MIS(Metal-Insulator-Semiconductor) structure by using PVP (Poly vinyl phenol) as a insulating layer, and CdSe/ZnS nano particles which have a core/shell structure inside. We dissolved PVP and PMF in PGMEA, organic solvent, then formed a thin film through a spin coating. After that, it was cross-linked by annealing for 1 hour in a vacuum oven at $185^{\circ}C$. We operated FTIR measurement to check this, and discovered the amount of absorption reduced in the wave-length region near 3400 cm-1, so could observe decrease of -OH. Boonton7200 was used to measure a C-V relationship to confirm a properties of the nano particles, and as a result, the width of the memory window increased when device including nano particles. Additionally, we used HP4145B in order to make sure the electrical characteristics of the organic thin film device and analyzed a conduction mechanism of the device by measuring I-V relationship. When the voltage was low, FNT occurred chiefly, but as the voltage increased, Schottky Emission occurred mainly. We synthesized CdSe/ZnS and to confirm this, took a picture of Si substrate including nano particles with SEM. Spherical quantum dots were properly made. Due to this study, we realized there is high possibility of application of next generation memory device using organic thin film device and nano particles, and we expect more researches about this issue would be done.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.467-468
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• 2006

We report on the fabrication of P3HT-based thin-film transistors (TFT) that consist of indium-zinc-oxide (IZO), PVP (poly-vinyl phenol), and Ni for the source-drain (S/D) electrode, gate dielectric, and gate electrode, respectively. The IZO S/D electrodes of which the work function is well matched to that of P3HT were deposited on a P3HT channel by thermal evaporation of IZO and showed a moderately low but still effective transmittance of ~25% in the visible range along with a good sheet resistance of ${\sim}60{\Omega}/{\square}$. The maximum saturation current of our P3HT-based TFT was about $15{\mu}A$ at a gate bias of -40V showing a high field effect mobility of $0.05cm^2/Vs$ in the dark, and the on/off current ratio of our TFT was about $5{\times}10^5$. It is concluded that jointly adopting IZO for the S/D electrode and PVP for gate dielectric realizes a high-quality P3HT-based TFT.

• Macromolecular Research
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• v.16 no.5
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• pp.446-456
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• 2008

A recent theoretical approach based on the coupling of both the Flory-Huggins (FH) and the Association Equilibria thermodynamic (AET) theories was modified and adapted to study the miscibility properties of a multi-component system formed by two polymers (a proton-donor and a proton-acceptor) and a proton-acceptor solvent, named copolymer(A)/solvent(B)/polymer(C). Compatibility between polymers was mainly attained by hydrogen-bonding between the hydroxyl group on the phenol unit of the poly(styrene-co-vinyl phenol) (PSVPh) and the carbonyl group of the biodegradable and environmentally friendly poly(3-hydroxybutyrate) (PHB). However, the self-association of PSVPh and specific interactions between the PSVPh and the H-acceptor group (an ether oxygen atom) of the epichlorohydrin (ECH) solvent were also established in a lower extension, which competed with the polymer-polymer association. All the binary specific interactions and their dependence with the system composition as well as with the copolymer content were evaluated and quantified by means of two excess functions of the Gibbs tree energy, ${\Delta}g_{AB}$ and ${\Delta}g_{AC}$. Experimental results from fluorescence spectroscopy were consistent with the theoretical simulations derived with the model, which could also be applied and extended to predict the miscibility in solution of any polymer blend with specific interactions.

• Polymer(Korea)
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• v.24 no.6
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• pp.886-892
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• 2000

Poly(4-vinyl phenol) (PVPh) was neutralized by LiOH and PVPh ionomers (PVPh-Li) with different Li neutralization extents were synthesized. The variation in $T_{g}$ with Li neutralization was determined by DSC and the results show that the $T_{g}$ increases by 3.$8^{\circ}C$ per Li mol%. When comparing this result with the 3.$2^{\circ}C$ per Na mol% reported for poly (styrene-co-hydroxy styrene), the greater value for PVPh-Li may be due to a strong interaction between unneutralized free -OH and -OLi produced. No distinct small angle X-ray scattering (SAXS) peak was observed for these PVPh ionomers in bulk. In the 50/50 blend of PVPh-Li with PVPh, the miscibile blend was obtained when the Li neutralization in PVPh-Li was 10 mol%. On the contrary, the 50/50 PVPh-Li/PMMA was immiscible when the Li neutralization was 5 mol%. It can be concluded that, even if the starting blend is miscible owing to hydrogen bonding, the miscibility of blend becomes diminished by introducing small amount of ion groups into one of the constituent polymers and the blend can be immiscible as long as any new strong intermolecular ion-dipole interaction is not generated.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1313-1314
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• 2007

This paper presents organic thin-film transistors (OTFTs) with poly(3-hexylthiophene)(P3HT) semiconductor and several polymeric dielectric materials of poly(vinyl phenol)(PVP), poly(vinyl alcohol)(PVA), and polyimide(PI) by using soluble process. The fabricated OTFT's have inverted staggered structure using transmission line method(TLM) pattern. In order to evaluate the electrical characteristics of the OTFT, capacitance-voltage(C-V) and current-voltage(I-V) were measured. C-V graphs were measured at several frequencies of 100 Hz, 1 kHz, and 1 MHz and ID-VDS graphs according to $V_{GS}$. The current on/off ratio and threshold voltage with each of PVP, PVA, and PI based OTFTs were measured to $10^3$, and -0.36, -0.41, and -0.62 V. Also, the calculated mobility with each of PVP, PVA, and PI was 0.097, 0.095, and 0.028 $cm^{2}V^{-1}s^{-1}$, respectively. In the cases of PVP and PVA, the hole mobility of P3HT was in excellent agreement with the published value of 0.1 $cm^{2}V^{-1}s^{-1}$.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1771-1773
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• 2007

Surface modification of the gate dielectric has a strong influence on the performance of printed transistors. The surface modification occurs between the gate dielectric and semiconductor. The printed transistor with evaporated vanadium pentoxide ($V_2O_5$) modification exhibits a mobility of $0.2cm^2\;V^{-1}\;s{-1}$ and a subthreshold slope of 1.47 V/decade.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.388-388
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• 2013

현대 사회에서 고집적 및 고성능의 전자소자의 필요성은 지속적으로 요구되고 있으며, 투명하거나 플렉서블한 특성의 필요성에 따라 이에 대한 기술개발이 이루어지고 있다. 특히, 이러한 특성을 만족하면서 대면적화 및 저온 공정의 특성을 지니는 유기물 반도체가 주목받고 있고, 이를 이용하여 OLED (Organic Light Emitting Diode), OTFT (Organic Thin Film Transistor)와 같은 다양한 유기물 반도체 소자가 개발되고 있다. 대표적인 예로는이 있다. 유기물 반도체 소자의 특성을 이용한 메모리 소자 또한 연구 및 개발이 지속되고 있으며, 유연성과 낮은 공정가격 등의 특성을 가지는 나노 입자들이 기존 Floating Gate의 대체물로 각광받고 있다. 본 논문에서는 MIS (Metal/Insulator/Semiconductor) 구조를 제작하고, Insulator 내부에Core/Shell 구조를 가지는 CdSe/ZnS 나노 입자를 부착하여 메모리 소자의 특성 확인 및 단위 면적당 개수에 따른 특성 변화를 확인하고자 하였다. 합성된 PVP (Poly 4-Vinyl Phenol)를 Insulator 층으로 사용하였으며 단위 면적당 나노 입자의 개수를 조절하여 제작된 MIS 소자를 Capacitance versus Voltage (C-V) 측정을 통하여 변화특성을 확인하였다.