• Title/Summary/Keyword: Center thickness

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Secondary Phase and Defects in Cu2ZnSnSe4 Solar Cells with Decreasing Absorber Layer Thickness

  • Kim, Young-Ill;Son, Dae-Ho;Lee, Jaebaek;Sung, Shi-Joon;Kang, Jin-Kyu;Kim, Dae-Hwan;Yang, Kee-Jeong
    • Current Photovoltaic Research
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    • v.9 no.3
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    • pp.84-95
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    • 2021
  • The power conversion efficiency of Cu2ZnSnSe4 (CZTSe) solar cells depends on the absorber layer thickness; however, changes in the characteristics of the cells with varying absorber layer thickness are unclear. In this study, we investigated the changes in the characteristics of CZTSe solar cells for varying absorber layer thickness. Five absorber thicknesses were employed: CZTSe1 2.78 ㎛, CZTSe2 1.01 ㎛, CZTSe3 0.55 ㎛, CZTSe4 0.29 ㎛, and CZTSe5 0.15-0.23 ㎛. The efficiency of the CZTSe solar cells decreased as the absorber thickness decreased, resulting in power conversion efficiencies of 10.45% (CZTSe1), 8.67% (CZTSe2), 7.14% (CZTSe3), 3.44% (CZTSe4), and 1.54% (CZTSe5). As the thickness of the CZTSe absorber layer decreased, the electron-hole recombination at the grain boundaries and the absorber-back-contact interface increased. This caused an increase in the current loss, owing to light loss in the long-wavelength region. In addition, as the thickness of the CZTSe absorber layer decreased, more ZnSe was produced, and the resulting defects and defect clusters led to an open-circuit voltage loss.

Electro-Optical characteristics with dielectric thickness of AC-PDP

  • Jung, K.B.;Choi, J.H.;Kim, S.B.;Jung, Y.;Choi, E.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.768-770
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    • 2003
  • In AC PDP, since charges generated by gas discharge are accumulated on the dielectric. The dielectric is a major factor to determine cell capacitance and its memory effect is a play an important role in PDP driving. In this experiment, we have investigated the electro-optical characteristics with dielectric thickness and we have analyzed wall charge and wall voltage by Q-V energy diagram. The dielectric thickness was varied from 20 um to 50 um. As results, according to the dielectric thickness increase,cell capacitance and power consumption is reduced.

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Clinical usefulness of facial soft tissues thickness measurement using 3D computed tomographic images (3차원 전산화단층촬영 영상을 이용한 안면 연조직 두께 계측의 임상적 유용성)

  • Jeong Ho-Gul;Kim Kee-Deog;Han Seung-Ho;Hu Kyung-Seok;Lee Jae-Bum;Park Hyok;Choi Seong-Ho;Kim Chong-Kwan;Park Chang-Seo
    • Imaging Science in Dentistry
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    • v.36 no.2
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    • pp.89-94
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    • 2006
  • Purpose : To evaluate clinical usefulness of facial soft tissue thickness measurement using 3D computed tomographic images. Materials and Methods : One cadaver that had sound facial soft tissues was chosen for the study. The cadaver was scanned with a Helical CT under following scanning protocols about slice thickness and table speed; 3 mm and 3 mm/sec, 5 mm and 5 mm/sec, 7 mm and 7 mm/sec. The acquired data were reconstructed 1.5, 2.5, 3.5 mm reconstruction interval respectively and the images were transferred to a personal computer. Using a program developed to measure facial soft tissue thickness in 3D image, the facial soft tissue thickness was measured. After the ten-time repeation of the measurement for ten times, repeated measure analysis of variance (ANOVA) was adopted to compare and analyze the measurements using the three scanning protocols. Comparison according to the areas was analyzed by Mann-Whitney test. Results : There were no statistically significant intraobserver differences in the measurements of the facial soft tissue thickness using the three scanning protocols (p>0.05). There were no statistically significant differences between measurements in the 3 mm slice thickness and those in the 5 mm, 7 mm slice thickness (p>0.05). There were statistical differences in the 14 of the total 30 measured points in the 5 mm slice thickness and 22 in the 7 mm slice thickness. Conclusion : The facial soft tissue thickness measurement using 3D images of 7 mm slice thickness is acceptable clinically, but those of 5 mm slice thickness is recommended for the more accurate measurement.

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The Optimization of Indium Zinc Oxide Thin Film Process in Color Filter on Array structure

  • Lee, Je-Hun;Kim, Jin-Suek;Jeong, Chang-Oh;Kim, Shi-Yul;Lim, Soon-Kwon;Souk, Jun-Hyung
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.1244-1247
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    • 2004
  • For obtaining the best panel quality of color filter on array(COA) architecture in TFF LCD, we investigated the influence of deposition temperature, $O_2$ flow, thickness on the optical transmittance, wet etching and adhesion properties of IZO deposited onto each color photo resist(red, green, blue). Average transmittance of the pixel single layer in the visible range(between 380 and 780nm) was mainly affected by thickness and showed maximum at 1250 ${\AA}$ while the thickness showing peak transparency in each R, G, B wavelength was different. The relation was calculated by using bi-layer transmission and reflectance model, which corresponded to experimental data very well. The adhesion of IZO deposited on each color PR was found to have enhanced value except red PR case, compared to that of IZO which was deposited on $SiN_x$. Wet etching pattern linearity was decreased as the thickness increased. The thickness of IZO was one of vital factors in order to optimize overall pixel process for fabricating COA structure.

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First trimester screening for trisomy 18 by a combination of nuchal translucency thickness and epigenetic marker level

  • Lee, Da Eun;Kim, Shin Young;Kim, Hyun Jin;Park, So Yeon;Kim, Min Hyoung;Han, You Jung;Ryu, Hyun Mee
    • Journal of Genetic Medicine
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    • v.14 no.1
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    • pp.1-7
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    • 2017
  • Purpose: The aim of this study was to assess the diagnostic efficacy of noninvasive prenatal screening for trisomy 18 by assessing the levels of unmethylated-maspin (U-maspin) and fetal nuchal translucency (NT) thickness during the first trimester of pregnancy. Materials and Methods: A nested case-control study was conducted using maternal plasma samples collected from 65 pregnant women carrying 11 fetuses with trisomy 18 and 54 normal fetuses. We compared the U-maspin levels, NT thicknesses, or a combination of both in the first trimester between the case and control groups. Results: U-maspin levels and NT thickness were significantly elevated in the first trimester in pregnant women carrying fetuses with trisomy 18 when compared to those carrying normal fetuses (27.2 vs. 6.6 copies/mL, P<0.001 for U-maspin; 5.9 vs. 2.0 mm, P<0.001 for NT). The sensitivities of the U-maspin levels and NT thickness in prenatal screening for fetal trisomy 18 were 90.9% and 90.9%, respectively, with a specificity of 98.1%. The combined U-maspin levels and NT thickness had a sensitivity of 100% in prenatal screening for fetal trisomy 18, with a specificity of 98.1%. Conclusion: A combination of U-maspin levels and NT thickness is highly efficacious for noninvasive prenatal screening of fetal trisomy 18 in the first trimester of pregnancy.

A study on the Conversion Loss by the Thickness of the Bonding Medium in the Elastic Delay Lines. (탄성파지연선에서 접착제의 두께에 의한 변환손실에 관하여)

  • 김종상;이전영
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.13 no.6
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    • pp.1-6
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    • 1976
  • In this paper, the methode of calculating conversion loss is proposed by considering the thickness of bonding medium between electrode and delay material in the vibrator of Elastic delay lines. As the result of computations using digital computer, it is shown that the thickness of bonding medium must be less than about 1/100 of the thickness of vibrator and when the thickness of electrode is about 1110 of vibrator, the center fnequency is shifted. When the thickness of bonding medium is equal to or more than the thickness of vibrator, the 리uctuations in frequency Bandwidth become larger and larger.

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Effect of EB-PVD Coated Si/HA Film Thickness on Surface Characteristics of Ti-35Nb-10Zr Alloy

  • Jeong, Yong-Hoon;Eun, Sang-Won;Choe, Han-Cheol
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2012.05a
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    • pp.213-213
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    • 2012
  • In this study, effect of EB-PVD coated Si/HA film thickness on surface characteristics of Ti-35Nb-10Zr alloy was investigated. The Ti-35Nb-10Zr alloy was fabricated by arc melting method. The Si/HA layers were coated with 0.8 wt.% of Si in pure HA by EB-PVD method. The coating thickness was consisted with 100 - 300 nm for each group, the surface characteristics was analyzed by FE-SEM, EDS, XRD, XRF and corrosion test. The Si/HA coating layer was well deposited on the alloy surface by EB-PVD, the thickness was correlative factor with HA peaks and corrosion resistance value.

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Correction of Dose Distribution at Total Body Irradiation using Compensator

  • Kim Jong Sik;Cho Hyun Sang;Kim Young Kon;Cho Jung Keun;Ju Sang Kyu;Park Young Hwan
    • The Journal of Korean Society for Radiation Therapy
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    • v.9 no.1
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    • pp.87-93
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    • 1997
  • The using of compensator is required to adjust the irregular dose distribution due to irregular thickness of the body in Total Body Irradiation. Aluminuim, copper or lead is generally used as compensator. In our study, we would like to introduce a result of the attenuation and compensation effect of radiation use compensator made by duralumin and its clinical use. The thickness of compensator was calculated by the attenustion of radiation, which was measured by polystyrene phantom and ionization chamber(farmer). The compensation effect of radiation was measured by diode detector. All of conditions were set as in real treatment, and the distanc from source to detector was 446 cm. We also made fixation of device to easily attach the compensator to LINAC. Beam spoiler was menufactured and placed on the patient to irradiate sufficient dose to the skin. diode detector were placed on head, neck, chest, umbilicus. pelvis and knee with each their entranced exit points, and datas of dose distribution were evaluated and compared in each points for eleven patients(Feb. 96-Feb. 97). The attenuation rate of irradiation by duralumin compensator was measured as $1.4\%$ in 2mm thickness. The mean attenuation rate was $1.3\%$ per 2mm as increasing the thickness gradually to 50 mm. By using duralunim compensator, dose distribution in each points of body was measured with ${\pm}2.8\%$ by diode detectior. We could easily calculate the thickness of compensator by measuring the attenuation rate of radiation, remarkably reduce the irragularity of dose distribution duo to the thickness of body and magnify the effect of radiation therapy.

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Improvement of evaporating efficiency for OLED mass-fabrication

  • Lee, Eung-Ki;Jeong, Seong-Ho;Jeong, Seok-Heon;Huh, Myung-Soo;Lee, Sung-Ho;Chung, Sung-Jin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.728-731
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    • 2002
  • For the evaporation process, thickness uniformity is of great practical importance. And, it is commercially significant to improve the efficiency of material of the evaporant which is deposited on the substrate because of high price of organic materials. To achieve the better thickness uniformity and the higher evaporating efficiency, Samsung SDI has introduced the new concept of the asymmetric evaporation technology for depositing evener and cheaper organic layers. Based on the developed method, the uniformity of the organic layer thickness can be successfully controlled. Furthermore, the very high efficiency may allow the OLED displays be manufactured with the lower cost.

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Characterization of Thickness and Electrical Properties of Ni-Cr Thin Films via Terahertz Time-domain Spectroscopy

  • Sunghun Kim;Inhee Maeng;Hyeon Sang Bark;Jungsup Byun;Jae Hun, Na;Seho Kim;Myeong Suk Yim;Byung-Youl Cha;Youngbin Ji;Seung Jae Oh
    • Current Optics and Photonics
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    • v.7 no.5
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    • pp.569-573
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    • 2023
  • We utilized terahertz time-domain spectroscopy (THz-TDS) to measure the thickness and electrical properties of nickel-chromium (Ni-Cr) films. This technique not only aligns well with traditional methods, such as haze-meter and transmission-densitometer measurements, but it also reveals the electrical properties and thickness of films down to a few tens of nanometers. The complex conductivity of the Ni-Cr thin films was extracted using the Tinkham formula. The experimental values closely aligned with the Drude model, indicating the reliability of our Ni-Cr film's electrical and optical constants. The thickness of Ni-Cr was estimated using the complex conductivity. These findings emphasize the potential of THz-TDS in quality control of metallic nanofilms, pointing toward an efficient and nondestructive test (NDT) for such analyses.