• Title/Summary/Keyword: insertion layer

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Performance improvement in bottom-contact pentacene organic thin-film transistors by the PMMA layer insertion

  • Lyoo, Ki-Hyun;Kim, Byeong-Ju;Lee, Cheon-An;Jung, Keum-Dong;Park, Dong-Wook;Park, Byung-Gook;Lee, Jong-Duk
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1139-1141
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    • 2006
  • For the bottom-contact pentacene organic thin-film transistors (OTFTs), the insertion of a thin PMMA layer $(20{\AA})$ between the pentacene and the electrode improves the electrical performances, such as carrier mobility and on-current magnitude, about 4 times larger than those of the devices without the PMMA. The performance enhancement is presumably due to the decreased contact resistance between metal and pentacene by inserting the thin PMMA layer.

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Improvement of Hybrid EL Efficiency in Nanoparticle EL Devices by Insertion of the Layers of PVK and BaF2

  • Lee, Jun-Woo;Cho, Kyoung-Ah;Kim, Hyun-Suk;Park, Byoung-Jun;Kim, Sang-Sig;Kim, Sung-Hyun
    • Transactions on Electrical and Electronic Materials
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    • v.6 no.3
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    • pp.101-105
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    • 2005
  • Electroluminescence(EL) and current-voltage(I-V) characteristics of hybrid EL devices containing Pr and Mn co-doped ZnS nanoparticles were investigated in this study. For the insertion of a hole transport layer of poly (N-vinyl carbazole)(PVK), the current level became lower due to the accumulation of electrons at the interface between PVK and nanoparticles. When both PVK and buffer layer $BaF_2$ were simultaneously introduced, the enhanced EL efficiency and improved I-V characteristics were obtained. This results from the additional increase of hole injection owing to the internal field induced by the significant accumulation of electrons at the interface. The presence of buffer layer $BaF_2$ together with PVK makes it possible the charge accumulation enough to induce the sufficient internal field for further hole injection.

Investigation on HT-AlN Nucleation Layers and AlGaN Epifilms Inserting LT-AlN Nucleation Layer on C-Plane Sapphire Substrate

  • Wang, Dang-Hui;Xu, Tian-Han
    • Journal of the Optical Society of Korea
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    • v.20 no.1
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    • pp.125-129
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    • 2016
  • In this study, we have investigated a high-temperature AlN nucleation layer and AlGaN epilayers on c-plane sapphire substrate by low-pressure metal-organic chemical vapor deposition (LP-MOCVD). High resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM), scanning electron microscope (SEM) and Raman scattering measurements have been exploited to study the crystal quality, surface morphology, and residual strain of the HT-AlN nucleation layer. These analyses reveal that the insertion of an LT-AlN nucleation layer can improve the crystal quality, smooth the surface morphology of the HT-AlN nucleation layer and further reduce the threading dislocation density of AlGaN epifilms. The mechanism of inserting an LT-AlN nucleation layer to enhance the optical properties of HT-AlN nucleation layer and AlGaN epifilm are discussed from the viewpoint of driving force of reaction in this paper.

Effect of Metal Barrier Layer for Flexible Solar Cell Devices on Tainless Steel Substrates

  • Kim, Kyoung-Bo
    • Applied Science and Convergence Technology
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    • v.26 no.1
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    • pp.16-19
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    • 2017
  • A thin metal layer of molybdenum is placed between the conventional barrier layer and the stainless steel substrate for investigating the diffusion property of iron (Fe) atoms. In this study, the protection probability was confirmed by measuring the concentration of out-diffused Fe using a SIMS depth profile. The Fe concentration of chromium (Cr) barrier layer with 10 nm molybdenum (Mo) layer is 5 times lower than that of Cr barrier without the thin Mo layer. The insertion of a thin Mo metal layer between the barrier layer and the stainless steel substrate effectively protects the out-diffusion of Fe atoms.

Effect of MgO Buffer Layer on the Structural Properties of Sputter-grown ZnO Thin Film (스퍼터링법으로 증착된 산화아연 박막의 구조적 성질에 대한 산화마그네슘 완충층의 효과 연구)

  • Lim, Young-Soo
    • Journal of the Korean Ceramic Society
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    • v.46 no.6
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    • pp.673-678
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    • 2009
  • The effect of MgO buffer layer on the structural properties of sputter-grown ZnO thin film was investigated. Sapphire (0001) and Si (100) substrate were used for the growth and MgO buffer layer was inserted between ZnO thin film and the substrate. X-ray diffraction pattern indicated that enhanced crystallinity in the ZnO thin film grown was achieved by inserting very thin MgO buffer layer, regardless of the substrate type. The strain in the ZnO thin film could also be controlled by the insertion of the MgO buffer layer, and tendency of the strain was strongly dependent on the substrate type.

The Clinical Analysis of Two Layer Vasovasostomy Using Silicone Tube (실리콘 관을 이용한 이층 정관정관 문합술)

  • Choi, Eui Chul;Choi, Hwan Jun;Yun, Jong Hyun;Kim, Yong Bae
    • Archives of Plastic Surgery
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    • v.36 no.2
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    • pp.183-187
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    • 2009
  • Purpose: Because of the volume of elective sterilizations performed in the world during the past decade, the vasectomy was a popular method for male sterilization in Korea and this, in turn, had been followed by an increase in the number of patient requiring vasectomy reversal with the high rate of subsequent divorce and remarriage. Recently, many authors have reported high success rates of vasovasostomy using microsurgical techniques and we performed modified two layer vasovasostomy with intravasal silicone tube to increase postoperative patency and pregnacy rate. Methods: Microscopic vasovasostomy was performed in 9 patients and their average age was $35.78{\pm}1.36years$(from 28 years to 44 years) from June 2006 to June 2008 at our department using modified two layer vasovasostomy with silicone tube insertion. Standard Guibor silicone tube, consisting of two 17.7 cm, 0.064 cm diameter, malleable, stainless steel probes connected by 29 cm of silicone tubing wedged onto disposable probes, were used in all cases. Results: Success rates were 88.8 % for patency and pregnancy 44.4 % for pregnancy in modified two layer vasovasostomy with silicone tube insertion. The patency rates were higher in cases of long postoperative day and in cases of short duration of vasectomy and vasovasostomy. Conclusion: We used a modified method to correspond the patency and pregnancy rate in microscopical modified two layer vasovasostomy using the intravasal silicone tube permanently. This method brings normal patency in microsurgical vasovasostomy because the silicone tube prevent obstruction of anastomosed site of the vas permanently.

Improving Stability and Characteristic of Circuit and Structure with the Ceramic Process Variable of Dualband Antenna Switch Module (Dual band Antenna Switch Module의 LTCC 공정변수에 따른 안정성 및 특성 개선에 관한 연구)

  • Lee Joong-Keun;Yoo Joshua;Yoo Myung-Jae;Lee Woo-Sung
    • Journal of the Microelectronics and Packaging Society
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    • v.12 no.2 s.35
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    • pp.105-109
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    • 2005
  • A compact antenna switch module for GSM/DCS dual band applications based on multilayer low temperature co-fired ceramic (LTCC) substrate is presented. Its size is $4.5{\times}3.2{\times}0.8 mm^3$ and insertion loss is lower than 1.0 dB at Rx mode and 1.2 dB at Tx mode. To verify the stability of the developed module to the process window, each block that is diplexer, LPF's and bias circuit is measured by probing method in the variation with the thickness of ceramic layer and the correlation between each block is quantified by calculating the VSWR In the mean while, two types of bias circuits -lumped and distributed - are compared. The measurement of each block and the calculation of VSWR give good information on the behavior of full module. The reaction of diplexer to the thickness is similar to those of LPF's and bias circuit, which means good relative matching and low value of VSWR, so total insertion loss is maintained in quite wide range of the thickness of ceramic layer at both band. And lumped type bias circuit has smaller insertion itself and better correspondence with other circuit than distributed stripline structure. Evaluated ceramic module adopting lumped type bias circuit has low insertion loss and wider stability region of thickness over than 6um and this can be suitable for the mass production. Stability characterization by probing method can be applied widely to the development of ceramic modules with embedded passives in them.

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Characteristics of Air-Gap Type FBARs Using ZnO Piezoelectric Thin Film With Varying Dimension of Sacrificial and Piezoelectric layer (희생층과 압전층의 면적변화에 따른 ZnO 압전박막을 이용한 Air-gap Type FBAR의 특성)

  • 고성용;장철영;최현철;이정희;이용현
    • Proceedings of the IEEK Conference
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    • 2001.06b
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    • pp.17-20
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    • 2001
  • In this paper, film bulk acoustic resonator(FBAR) with an air-gap is fabricated by removing ZnO sacrificial layer and its characteristics as a various dimension of ZnO sacrificial and piezoelectric layer is evaluated. The center frequency of the FBAR device with the ZnO film is about 1.9 GHz. Because of mass-loading effect, a dimension of sacrificial layer and piezoelectrc layer affect frequency response such as center frequency, insertion loss, band separation, attenuation and so on.

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Red emission organic light-emitting diode with electrochemically deposited PANI-CSA layer

  • Kim, Ju-Seung;Kim, Dae-Jung;Gu, Hal-Bon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.08a
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    • pp.81-84
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    • 2003
  • Conductive polyaniline(PANI)-camphosulfonic acid (CSA) film applied as a hole injection layer in ITO/PANI/P3HT/LiF/Al device. In the AFM images, electrochemically polymerized PANI-CSA films have the small particles and smooth sufficient for application as hole injection layer. By insertion of PANI-CSA buffer layer, the turn on voltage of ITO/PANI/P3HT/LiF/Al device lowed by 3V, whereas that of ITO/P3HT/LiF/Al device shows 5V.

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