• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.560-562
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• 2009

In this paper, we proposed a simple method of decreasing the off current generated by degradation for improve the electrical characteristics such as mobility and on/off current ratio by making the line patterns on the pentacene surface between the electrodes using atomic force microscope (AFM) lithography.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1736-1738
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• 2000

ITO/TPD($450{\AA}$)/$Alq_{3}(500{\AA})$/Al:Li($1200{\AA}$) 구조의 유기 LED를 제작하였다. Al과 Al:Li(0.lwt%), Al:Li(1wt%), Al:Li(5wt %) 합금을 음전극으로 증착시켜 소자의 전기적 광학적 특성을 분석하였다. 음전극 내의 Li의 분포를 알아보기 위하여 SIMS(Secondary ion Mass Spectroscopy) depth profiling을 하였다. Al:Li합금에서 Li의 함량이 0.1 wt %에서 5 wt %로 증가함에 따라 소자의 turn-on voltage는 약 3.5 V에서 3 V로 감소하였고, 구동전압도 감소하였다. 200$cd/m^2$의 휘도를 기준으로 Al:Li(0.1wt %) 합금을 사용한 소자의 경우 3.5 lm/W로 발광효율이 최대였다. 증착된 Al:Li(0.1wt%) 합금의 SIMS depth profiling 결과 초기에만 Al:Li이 증착되어 Al:Li/Al의 두 층이 형성되었고, Al:Li 합금층의 두께는 약 120${\AA}$ 이었다.

• ETRI Journal
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• v.34 no.6
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• pp.970-973
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• 2012

In this letter, we report on the development progress of a pressure control organic vapor deposition (PCOVD) technology used to design and build a large area deposition system. We also investigate the growth characteristics of a pentacene thin film by PCOVD. Using the PCOVD method, the mobility and on/off current ratio of an organic thin-film transistor (OTFT) on a plastic substrate are $0.1cm^2/Vs$ and $10^6$, respectively. The developed OTFT can be applied to a flexible display on a plastic substrate.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.162-163
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• 2006

Control over surface induced self-assembly of electronically active pi-conjugated molecules provides great opportunities to fine-tune and optimize their electrical properties in organic electronics. In this study, with the aim of enhancing the electrical performances by promoting surface induced two-dimensional self-assembly in representative pi-conjugated molecules such as poly (3-hexylthiophene) and pentacene, we have controlled the intermolecular interaction at the interface between pi-conjugated molecules and substrate by using self-assembled monolayers functionalized with various groups. We will discuss the dependency of pi-conjugated molecules on the specific properties of the substrate surface and the effect of surface induced self-assembly on electrical performances in organic transistors.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.343-343
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• 2011

ZnO has been introduced as one of the good candidates for next generation opto-electronics. Recently, ZnO is known to be suitable for the transparent electrode in organic solar cells and light emitting devices. The contact with n-type organic material has been studied due to the n-type properties of ZnO. However, the surface of ZnO has shown different electronic property with respect to its surface orientation. Therefore, it is presumed that there are differences in the interfacial electronic structures between organic materials and ZnO with different orientation. Therefore, it is required to classify the interfacial electronic structures according to the surface orientation of ZnO. In this study, we measured the interfacial electronic structures between the ZnO substrate having various orientations and a typical n-type organic material, tris-(8-hydroxyquinoline) aluminum (Alq3). In-situ x-ray and ultraviolet photoelectron spectroscopy measurements revealed the interfacial electronic structures. We found the changes in the electronic structures with respect to the orientation of ZnO substrate and it could be used to improve the contact between ZnO and Alq3.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.64-66
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• 2009

We obtained high performance of n-type organic thin film transistors (OTFTs) using a solution process. N, N' bis-(octyl-)-dicyanoperylene-3,4:9,10-bis(dicarboximide) (PDI-$8CN_2$) in ambient air. Low work function interlayer on source/drain is needed to enhance the electron injection to low LUMO level of n-type organic semiconductor. By using self-assembled monolayer (SAM) the field-effect mobility of 0.33 $cm^2$/Vs was achieved.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.10-11
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• 2006

The azobenzene dendrimer is one of the dendrimeric macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and photoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current. Functional photoisometrization organic molecular the photo-stimulus to organic monomolecular L films and LB films of dendrimer and SASH were performed. The SASH organic monolayer in case of pressure stimulus occurred that positive course but in case of the photo-stimulus compared positive and negative. It is assumed that generation forms of displacement current were measured when photo-stimulus for impression.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.14.1-14.1
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• 2009

We found a high yield synthetic route to organic-soluble metal nanoparticles in the concentrated organic phase. The organic phase contains metal salt, amines, fatty acids, nonpolar solvent, and reducing agent. Even using only generic chemicals, organic-soluble silver and copper nanoparticles could be easily obtained by this simple and rapid reaction scheme at large scale. The hydrocarbon-protected metal nanoparticles showed excellent dispersion properties and were successfully printed onto polymer substrates. The printed pattern was heated at $200^{\circ}C$, which showed very low specific electrical resistance (< 10 uOhm$\cdot$cm), sufficient for conducting line of various printable devices.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.3 s.357
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• pp.1-5
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• 2007

SiOC films were made using the oxygen and bistrimethylsilylmethane mixed precursor. The chemical properties of SiOC films divided into three properties, organic, hybrid and inorganic depending on the flow rate ratio between oxygen and bistrimethylsilylmethane precursor. The films with organic properties decreased dielectric constant, because of pore incorporation in final materials. In this study, the porosity of SiOC films with organic properties was investigated using the Makwell-Garnett equation. The porosity of the films could be correlated with the blue shift in the infrared spectra scopy, and increased with the decreasing the dielectric constant of the film.

• JSTS:Journal of Semiconductor Technology and Science
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• v.5 no.2
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• pp.77-82
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• 2005

We compare electrical and optical properties of organic light emitting diodes (OLEDs) using rhodium-oxide-coated indium-tin-oxide ($O_2$-Rh/ITO) to that using $O_2$-plasma-treated ITO (ITO) anodes. The turn-on voltage decreased from 7 V to 5 V and luminance value increased when the $O_2$ plasma treated Rh layer was deposited on ITO. Synchrotron radiation photoelectron spectroscopy results showed the dipole energies of both ITO and $O_2$-Rh/ITO were same with each other, - 0.3 eV, meaning the formation of same amount of interface dipole. The secondary electron emission spectra revealed that the work function of $O_2$-Rh/ITO is higher hy 0.2 eV than that of ITO, resulting in the decrease of the tum-on voltage via reduction ofhole injection barrier.