• Title/Summary/Keyword: Carrier density

Search Result 546, Processing Time 0.028 seconds

Theoretical Analysis of the Electrical Saturation Behavior of the DH Laser Diode (DH Laser Diode의 전기적 포화현상에 관한 이론적 해석)

  • 박영규;권영기
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.15 no.5
    • /
    • pp.34-38
    • /
    • 1978
  • In this Paper, the saturation behavior in the electrical phenomena of the DH Laser diode is explained theoretically using rate equnations. The carrier density approaches to ns gradually well above the threshold and theoretically expected curve of and calculated value of $\Delta$Vj are exactly equal to the experimental results which was observed, as shown. The carrier saturation factor If is proposed and we show k$\beta$ is a measure of the ideality of the sample diode. In the light of relation, the sample diode's idoality increases as f decreases.

  • PDF

Preparation of High-purity Porous Alumina Carrier for Gas Sensor (가스센서용 고순도 다공질 알루미나 담체의 제조)

  • 이창우;현성호;함영민
    • Fire Science and Engineering
    • /
    • v.11 no.3
    • /
    • pp.15-23
    • /
    • 1997
  • In this study, the alumina for gas sensor was prepared by anodic oxidation. It was stable thermally and chemically, and pore diameter and pore distribution was uniform. And the shape of pore was cylinderical. The aluminum plate was carried out by the thermal oxidation, chemical polishing and electropolishing pretreatment. The pore diameter, pore size distribution, pore density and thickness of alumina was observed with the change of reaction temperature, electrolyte concentration and current density. As a results, It was able to use for carrier because alumina which was prepared by anodic oxidationhas uniform pore size distribution.

  • PDF

A Study on Buffered Deposition Device Structure to Improvement for High Density Chip Realiability (고밀도 칩 신뢰성 개선을 위한 buffered deposition 소자구조에 관한 연구)

  • Kim, Hwan-Seog;Yi, Cheon-Hee
    • Journal of the Korea Society for Simulation
    • /
    • v.17 no.2
    • /
    • pp.13-19
    • /
    • 2008
  • New Buffered deposition is proposed to decrease junction electric field in this paper. Buffered deposition process is fabricated after first gate etch, followed NM1 ion implantation and deposition & etch nitride layer. New Buffered deposition structure has buffer layer to decrease electric field. Also we compared the hot carrier characteristics of Buffered deposition and conventional. Also, we design a test pattern including NMOSFET, PMOSFET, LvtNMOS, High pressure N/PMOSFET, so that we can evaluate DC/AC hot carrier degradation on-chip. As a result, we obtained 10 years hot carrier life time satisfaction.

  • PDF

A study of Analysis for 150K DWT Class Bulk carrier(BC-B type) (BC-B Type150K DWT Class Bulk carrier 구조적 특성에 관한 고찰)

  • Seo, Hyang-Duk;Kim, Do-Koon;Ahn, Hyung-Joon
    • Special Issue of the Society of Naval Architects of Korea
    • /
    • 2015.09a
    • /
    • pp.79-84
    • /
    • 2015
  • A BC-B type bulk carrier is rarely built, so the structural characteristics is not reported and familiar so far. The biggest difference between BC-B and BC-A type vessel is applying alternate cargo loading, which density is over $1.0ton/m^3$. In this paper, 150K DWT class BC-B type bulk carrier is calculated and compared with BC-A type vessel, which has same condition such as main dimension and deadweight, about prescriptive rule and FEA based on CSR. And aspect ratio of target vessel is smaller than typical capsize bulk carrier, so 150K and 180K bulk carrier, which applied BC-A type, are also compared to find feature of wide beam vessel.

  • PDF

A Study on the Transport Mechanism of a SCH Quantum-Well Laser Diode and on the Modulation Characteristics (SCH 양자우물 레이저 다이오드의 수송기구와 변조응답 특성에 관한 연구)

  • Kim, Jong-Gi;Jeong, Jea-Yong;Suh, Chung-Ha
    • Journal of the Institute of Electronics Engineers of Korea TE
    • /
    • v.37 no.1
    • /
    • pp.27-34
    • /
    • 2000
  • In this paper, carrier transport mechanism and modulation response for SCH(Separate Confinement Heterostructure) SQW(Single Quantum Well) laser diodes were studied. In order to explain carrier transport mechanism, both carrier density and current density were calculated. The recombination current density in the quantum well as a function of the SCH length was also calculated. For the modulation response, linearizing the rate equation, we calculated the bandwidth, relaxation oscillation frequency, damping factor, and the K-factor.

  • PDF

Effect of Carrier Gases on the Microstructure and Properties of Ti Coating Layers Manufactured by Cold Spraying (저온 분사 공정으로 제조된 Ti 코팅층의 미세조직 및 물성에 미치는 송급 가스의 영향)

  • Lee, Myeong-Ju;Kim, Hyung-Jun;Oh, Ik-Hyun;Lee, Kee-Ahn
    • Journal of Powder Materials
    • /
    • v.20 no.1
    • /
    • pp.24-32
    • /
    • 2013
  • The effect of carrier gases (He, $N_2$) on the properties of Ti coating layers were investigated to manufacture high-density Ti coating layers. Cold spray coating layers manufactured using He gas had denser and more homogenous structures than those using $N_2$ gas. The He gas coating layers showed porosity value of 0.02% and hardness value of Hv 229.1, indicating more excellent properties than the porosity and hardness of $N_2$ gas coating layers. Bond strengths were examined, and coating layers manufactured using He recorded a value of 74.3 MPa; those manufactured using $N_2$ gas had a value of 64.6 MPa. The aforementioned results were associated with the fact that, when coating layers were manufactured using He gas, the powder could be easily deposited because of its high particle impact velocity. When Ti coating layers were manufactured by the cold spray process, He carrier gas was more suitable than $N_2$ gas for manufacturing excellent coating layers.

Effect of Different Carrier Agents on Physicochemical Properties of Spray-dried Pineapple (Ananas comosus Merr.) Powder

  • Quoc, Le Pham Tan
    • Journal of the Korean Chemical Society
    • /
    • v.64 no.5
    • /
    • pp.259-266
    • /
    • 2020
  • The main purpose of this study is to examine the different physicochemical properties of spray-dried products. The carrier agents and powders after the spray-drying process were analyzed for encapsulation yield, moisture content, color parameters, total polyphenol content (TPC), antioxidant capacity (AC), bulk density, flowability, wettability, hygroscopicity, water solubility index (WSI), particle size and microstructure. The spray-drying process was carried out with different carrier agents including maltodextrin (MD) and the combination of maltodextrin and gum arabic (MD-GA) with MA/GA ratio of 70/30, dried at the inlet/outlet air temperature of 160 ℃/70 ℃, 4 bar, airflow rate of 70 ㎥·h-1 and feed flow rate of 750 mL·h-1. The results showed that the different carrier agents have significant influences on the physicochemical properties of the powder produced by the spray-drying method. In there, while the values of recovery efficiency and flowability of spray-dried products from MD are higher than those of spray-dried products from MD-GA combination, the opposite is true for the values of TPC, AC, bulk density and wettability, whereas hygroscopicity and WSI values are equally represented in both products.

Comparison of Characteristics Between Thermal Evaporated SiO and rf Sputtered $SiO_2$ Thin Films by Trap Density Measurements (포획준위 밀도 예정을 통한 열증착한 일산화규소 박막과 고주파 스퍽터링한 이산화규소 박막의 특성비교)

  • 마대영;김기완
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.24 no.4
    • /
    • pp.625-630
    • /
    • 1987
  • Thermal evaporated SiO rf sputtered SiO2 thin films were most widely used to the gate oxide of TFTs. In this paper, the difference of trap density and distribution between SiO2 and SiO2 film were studied. TFTs using SiO and SiO2 thin film for the gate oxide were fabricated. The output characteirstics of TFTs and the time dpendencd of the leakage current were measured. Models of the carrier transport and carrier trapping in TFT were proposed. The trap density was obtained by substituting measured value for the equation derived from the proposed model. It was found that rf sputtered SiO2 had more traps at interface than thermal evaporated SiO.

  • PDF

Numerical Analysis on Heat Transfer Characteristics in Silicon Boated by Picosecond-to-Femtosecond Ultra-Short Pulse Laser (펨토초급 극초단 펄스레이저에 의해 가열된 실리콘 내의 열전달 특성에 관한 수치해석)

  • 이성혁;이준식;박승호;최영기
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.26 no.10
    • /
    • pp.1427-1435
    • /
    • 2002
  • The main aim of the present article is numerically to investigate the micro-scale heat transfer phenomena in a silicon microstructure irradiated by picosecond-to-femtosecond ultra-short laser pulses. Carrier-lattice non-equilibrium phenomena are simulated with a self-consistent numerical model based on Boltzmann transport theory to obtain the spatial and temporal evolutions of the lattice temperature, the carrier number density and its temperature. Especially, an equilibration time, after which carrier and lattice are in equilibrium, is newly introduced to quantify the time duration of non-equilibrium state. Significant increase in carrier temperature is observed for a few picosecond pulse laser, while the lattice temperature rise is relatively small with decreasing laser pulse width. It is also found that the laser fluence significantly affects the N 3 decaying rate of Auger recombination, the carrier temperature exhibits two peaks as a function of time due to Auger heating as well as direct laser heating of the carriers, and finally both laser fluence and pulse width play an important role in controlling the duration time of non-equilibrium between carrier and lattice.