• Title/Summary/Keyword: Submicron

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Synthesis of Submicron Silver Particle Using Room Temperature Ionic Liquids (상온 이온성 액체를 이용한 미세 은 입자 제조)

  • Yoo, Kye Sang
    • Applied Chemistry for Engineering
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    • v.23 no.1
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    • pp.14-17
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    • 2012
  • Submicron silver particles were synthesized by chemical reduction with various room temperature ionic liquids. The size and distribution of silver particles were significantly affected by the anion type of ionic liquids and this is mainly attributed to the different abilities of the anions to coordinate with the silver particle, leading to various coagulation of silver particles. Among ionic liquids, 1-butyl-3-methylimidazolium hexafluorophosphate was the most effective to synthesize submicron silver particles.

Scale-up of Optimized Chemical Processes for Micron and Submicron Products (마이크론 이하 단위의 제품생산 최적화를 위한 화학공정의 스케일업)

  • Chung, Young Mi
    • Applied Chemistry for Engineering
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    • v.28 no.1
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    • pp.17-22
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    • 2017
  • This review deals with scale-up strategies for optimized chemical processes particularly for micron and submicron products. The method of finding scale-up factors was also introduced for two systems, a system with chemical reaction and a system without chemical reaction. This review is expected to serve as an initial guideline for process engineers who are to scale up their current chemical processes for small products of micron or submicron size.

Effects of Thermal-Carrier Heat Conduction upon the Carrier Transport and the Drain Current Characteristics of Submicron GaAs MESFETs

  • Jyegal, Jang
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 1997.11a
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    • pp.451-462
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    • 1997
  • A 2-dimensional numerical analysis is presented for thermal-electron heat conduction effects upon the electron transport and the drain current-voltage characteristics of submicron GaAs MESFETs, based on the use of a nonstationary hydrodynamic transport model. It is shown that for submicron GaAs MESFETs, electron heat conduction effects are significant on their internal electronic properties and also drain current-voltage characteristics. Due to electron heat conduction effects, the electron energy is greatly one-djmensionalized over the entire device region. Also, the drain current decreases continuously with increasing thermal conductivity in the saturation region of large drain voltages above 1 V. However, the opposite trend is observed in the linear region of small drain voltages below 1 V. Accordingly, for a large thermal conductivity, negative differential resistance drain current characteristics are observed with a pronounced peak of current at the drain voltage of 1 V. On the contrary, for zero thermal conductivity, a Gunn oscillation characteristic is observed at drain voltages above 2 V under a zero gate bias condition.

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Preparationof High Purity, Submicron BaTiO3 Powder Prepared by Hydrothermal Reaction (수열반응에 의한 고순도 극미립자 BaTiO3 분말합성)

  • 김경용;김윤호;손용배
    • Journal of the Korean Ceramic Society
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    • v.26 no.4
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    • pp.493-498
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    • 1989
  • High purity, submicron BaTiO3 powder was prepared by a hydrothermal technique using Ba(OH)2.8H2O, TiCl4 and NH4OH as starting raw materials. The submicron BaTiO3 powder was synthesized at 130~23$0^{\circ}C$ for 2.5h to yield highly crystalline particles with a narrow particle distribution. The mole ratio of Ba(OH)2.8H2O/TiO(OH)2 was 1.5. It is possible to obtain BaTiO3 with Ba : Ti=1.00$\pm$0/01. The samples densified well at 13$25^{\circ}C$, showing a uniform and fine grain structure. The grain size ranged between 0.3 and 0.5${\mu}{\textrm}{m}$. The products obtained by hydrothermal treatment at various temperatures from 130 to 23$0^{\circ}C$ were characterized by XRD, DTA, BET and SEM etc.

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Development of Metal Substrate with Multi-Stage Nano-Hole Array for Low Temperature Solid Oxide Fuel Cell (저온 고체산화물연료전지 구현을 위한 다층 나노기공성 금속기판의 제조)

  • Kang, Sangkyun;Park, Yong-Il
    • Journal of the Korean Ceramic Society
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    • v.42 no.12 s.283
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    • pp.865-871
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    • 2005
  • Submicron thick solid electrolyte membrane is essential to the implementation of low temperature solid oxide fuel cell, and, therefore, development of new electrode structures is necessary for the submicron thick solid electrolyte deposition while providing functions as current collector and fuel transport channel. In this research, a nickel membrane with multi-stage nano hole array has been produced via modified two step replication process. The obtained membrane has practical size of 12mm diameter and $50{\mu}m$ thickness. The multi-stage nature provides 20nm pores on one side and 200nm on the other side. The 20nm side provides catalyst layer and $30\~40\%$ planar porosity was measured. The successful deposition of submicron thick yttria stabilized zirconia membrane on the substrate shows the possibility of achieving a low temperature solid oxide fuel cell.

Flower like Buffer Layer to Improve Efficiency of Submicron-Thick CuIn1-xGaxSe2 Solar Cells

  • Park, Nae-Man;Cho, Dae-Hyung;Lee, Kyu-Seok
    • ETRI Journal
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    • v.37 no.6
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    • pp.1129-1134
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    • 2015
  • In this article, a study of a flower like nanostructured CdS buffer layer for improving the performance of a submicron-thick $CuIn_{1-x}Ga_xSe_2$ (CIGS) solar cell (SC) is presented. Both its synthesis and properties are discussed in detail. The surface reflectance of the device is dramatically decreased. SCs with flower like nanostructured CdS buffer layers enhance short-circuit current density, fill factor, and open-circuit voltage. These enhancements contribute to an increase in power conversion efficiency of about 55% on average compared to SCs that don't have a flower like nanostructured CdS buffer layer, despite them both having the same CIGS light absorbing layer.

Optical Failure Analysis Technique in Deep Submicron CMOS Integrated Circuits

  • Kim, Sunk-Won;Lee, Hyong-Min;Lee, Hyun-Joong;Woo, Jong-Kwan;Cheon, Jun-Ho;Kim, Hwan-Yong;Park, Young-June;Kim, Su-Hwan
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.11 no.4
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    • pp.302-308
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    • 2011
  • In this paper, we have proposed a new approach for optical failure analysis which employs a CMOS photon-emitting circuitry, consisting of a flip-flop based on a sense amplifier and a photon-emitting device. This method can be used even with deep-submicron processes where conventional optical failure analyses are difficult to use due to the low sensitivity in the near infrared (NIR) region of the spectrum. The effectiveness of our approach has been proved by the failure analysis of a prototype designed and fabricated in 0.18 ${\mu}m$ CMOS process.

Nano and Submicron Sized Particle Collection with Various Voltage Waveforms for Dielectric Barrier Discharge Type 2-Stage ESP (유전체 베리어 방전형 2단 전기집진기의 인가전압 파형별 나노 및 서브마이크론 입자 집진 특성)

  • Park, Jae-Hong;Byeon, Jeong-Hoon;Hwang, Jung-Ho
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1261-1266
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    • 2004
  • Dielectric Barrier Discharge (DBD) in air, which has been established for the production of large quantities of ozone, is more recently being applied to a wider range of aftertreatment processes for HAPs (Hazardous Air Pollutants). Although DBD has high electron density and energy, its potential use as precharging nano and submicron particles are not well known. In this work, we measured I-V characteristics of DBD and estimated collection efficiency of the particles by DBD type 2-stage ESP. To examine the particle collection with various applied voltage waveforms of DBD for nano and submicron sized, bimodal particles were generated by a electrical tube furnace and an atomizer.

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Electrical properties and thermal stability of Al/$WN_x$/Ti submicron contact structure

  • Kim, Yong-Tae;Sim, Hyun-Sang;Kim, Seong-Il
    • Proceedings of the Korean Society Of Semiconductor Equipment Technology
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    • 2002.11a
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    • pp.72-74
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    • 2002
  • A submicron contact scheme using $WN_x$ diffusion barrier has been suggested for multilevel interconnect structure. The contact resistance of $0.4\times0.48\mu\textrm{m}^2$ size Al/WN/Ti/$n^+$-Si is 120-140 $\Omega$ and the leakage current density is below than $10^{-16}$$-10^{-15}A/\mu\textrm{m}^2$. The effect of F atoms on the submicron contact has been investigated with the nuclear resonance analysis method.

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