• 제목/요약/키워드: Full width half maximum

검색결과 426건 처리시간 0.024초

Micro-Cavity Effect of ZnO/Ag/ZnO Multilayers on Green Quantum Dot Light-Emitting Diodes

  • Lee, Hyungin;Kim, Jiwan
    • 한국세라믹학회지
    • /
    • 제55권2호
    • /
    • pp.174-177
    • /
    • 2018
  • ZnO/Ag/ZnO multilayers were fabricated and their optical properties were investigated in terms of the micro-cavity effect in electroluminescent devices based on colloidal quantum dots. The top and bottom ZnO layers were formed by a sol-gel method while the middle Ag layer was deposited by thermal evaporation. After the fabrication of the ZnO/Ag/ZnO structure, the transmittance increased to 74%. When the oxide/metal/oxide multilayers were applied to quantum dot light-emitting diodes, the color purity was enhanced due to the narrower full width at half maximum.

기계적 후면 손상이 레이저/극초단파 광전도 기법에 의한 소수 반송자 재결합 수명 측정에 미치는 영향 (Effect of mechanical backside damage upon minority carrier recombination lifetime measurement by laser/microwave photoconductance technique)

  • 조상희;최치영;조기현
    • 한국결정성장학회지
    • /
    • 제5권4호
    • /
    • pp.408-413
    • /
    • 1995
  • 초크랄스키 실리콘 기판의 뒷면에 형성된 기계적 손상이 레이저 여기/극초단파 반사 광전도 감쇠법에 의한 소수반송자 재결합 수명 측정에 미치는 영향을 고찰하였다. 기계적손상의 정도는 X-선 이중결정 회절법과 X-선 단면 측정법 및 습식산화/선택적 식각 방법으로 평가하였다. 그 결과, 웨이퍼 뒷면에 가해지는 기계적 손상의 세기가 강할수록 소수반송자 재결합 수명은 짧아지고, 소수반송자 재결합 수명 측정에 영향을 미치는 반치전폭의 임계값은 약13초임을 알 수 있다.

  • PDF

분산값이 서로 다른 파이버들을 이용한 광펄스의 압축과 기본솔리톤 생성 (Comression of optical pulse and generation of fundamental soliton byusing fibers which have different dispersion values)

  • 윤수영;안규철;송윤원;최병하
    • 한국통신학회논문지
    • /
    • 제21권11호
    • /
    • pp.3012-3023
    • /
    • 1996
  • In this paper, we analyze the compression of optical soliton which is obtained by proceeding the optical pulse in FSDD(Fiber with Slowly Decreasing Dispersion) using both NSE(Nonlinear Schrodinger Equation) and GNSE(General Nonlinear Schrodinger Equation) and compare the results. We replace the FSDD with a sequence of fibers having different dispersion values and pompre the results with those obtained in FSDD. It is found that the same results in peak value and FWHM(Full width Half Maximum) can be obtained by replacing FSDD with a sequence of fibers having proper length. We vary the shape of initial pulse which is the input of FSDD and suggest the condition to obtain higher compression rate.

  • PDF

레이저 증착법에 의한 탄소계 박막의 구조 및 전계방출특성 (Deposition of Carbon Thin Film using Laser Ablation and Its Field Emission Properties)

  • 류정탁;;김연보
    • 한국전기전자재료학회논문지
    • /
    • 제15권7호
    • /
    • pp.634-639
    • /
    • 2002
  • Using laser ablation technique carbon thin films were deposited on Si(100) substrate as a function of substrate temperature. In this study, the surface morphologic, structural and field emission properties of these carbon thin films were investigated using Raman spectroscopy, scanning electron microscopy, and a diode technique, respectively. With increasing of the substrate temperature, the surface morphologies were changed significantly. Moreover, the intensity of D-band and the full width at half maximum of these bands were dependent on substrate temperatures. As the substrate temperature was increased, the field emission properties were improved. As the result, we find that the field emission properties of the films were changed significantly with the substrate temperature and structural features of carbon than films.

Initial Growth Mode and Epitaxial Growth of AIN Thin Films on $Al_2O_3(0001)$ Substrate by DC Faced Target Sputtering

  • Kim, Jin-Woo;Kang, Kwang-Yong;Lee, Su-Jae
    • The Korean Journal of Ceramics
    • /
    • 제5권4호
    • /
    • pp.368-370
    • /
    • 1999
  • Using DC faced target sputtering method we grow AIN the films on the $Al_2O_3$(0001) substrate with varying thickness(17$\AA$-1000$\AA$). We measured x-ray diffraction(XRD) profiles by synchrotron radiation($\lambda$=1.12839 $\AA$) with four circle diffractometer. The full width half maximum(FWHM) of rocking curve for the AIN (0002) diffraction of the film grown at $500^{\circ}C$ was $0.029^{\circ}$. Also, we confirmed that the stress between AIN thin film and $Al_2O_3$(0001) substrate was reduced as increasing AIN film thickness, and the critical thickness of 400~500 $\AA$, defined as a lattice constant in the film agrees with that in a bulk without stress, was obtained.

  • PDF

Binding energy study from photocurrent signal in HgCdTe layers

  • Hong, Kwang-Joon
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
    • /
    • pp.379-379
    • /
    • 2010
  • $Hg_{1_x}Cd_xTe$ (MCT) was grown by hot wall epitaxy. Prior to the MCT growth, the CdTe (111) buffer layer was grown on the GaAs substrate at the temperature of $590^{\circ}C$ for 15 min. When the thickness of the CdTe buffer layer was $5\;{\mu}m$ or thicker, the full width at half maximum values obtained from the x-ray rocking curves were found to significantly decrease. After a good quality CdTe buffer layer was grown, the MCT epilayers were grown on the CdTe (111) /GaAs substrate at various temperatures in situ. The crystal quality for those epilayers was investigated by means of the x-ray rocking curves and the photocurrent experiment. The photoconductor characterization for the epilayers was also measured. The energy band gap of MCT was determined from the photocurrent measurement and the x composition rates from the temperature dependence of the energy band gap were turned out.

  • PDF

HIGH RESOLUTION NEAR-INFRARED SPECTRA OF NEARBY QUASAR, PG1426+015

  • ;;임명신
    • 천문학회보
    • /
    • 제37권1호
    • /
    • pp.51.1-51.1
    • /
    • 2012
  • We observed low-z quasar PG1426+015 (z=0.086), using the near-IR high resolution echelle spectrometer, IRCS, at the SUBARU 8.2 m telescope. Using an Adoptive Optics system, the full width at half maximum of the point spread function was about 0.3 arcsec, which can effectively separate the quasar spectra from the host galaxy spectra. We also maximize the total exposure time up to several hours per target, and develop data reduction methods to increase the signal-to-noise ratios. This poster presents the data reduction processes and sample spectra from the quasar and its host galaxy. These spectral lines will be used to study the physical mechanism of quasars, and the velocity dispersions of the stars in the bugle of the host galaxy.

  • PDF

금속 슬릿 주변에 유전체 chirped grating을 배열함으로써 구현한 beam focusing (Beam focusing by a single subwavelength metal slit surrounded by chirped dielectric surface gratings)

  • 김세윤;박정현;임용준;김휘;이병호
    • 한국광학회:학술대회논문집
    • /
    • 한국광학회 2007년도 하계학술발표회 논문집
    • /
    • pp.255-256
    • /
    • 2007
  • We propose a novel method for the beam focusing by a single subwavelength metal slit surrounded by chirped dielectric surface gratings. In the proposed method, the period of each grating is chirped to make a focused beam at the desired position. Design of the grating structures for optimal beam focusing and the analysis of the field distribution are conducted based on the rigorous coupled wave analysis (RCWA). It is shown that the focused beam is formed at 1.5${\mu}m$ from the metal substrate and its full width at half maximum (FWHM) is 411nm.

  • PDF

수직 Bridgman 법에 의한 CdTe 단결정 성장과 특성 (Growth and characterization of CdTe single crystal by vertical Bridgman method)

  • 홍명석;홍광준
    • 센서학회지
    • /
    • 제14권6호
    • /
    • pp.369-373
    • /
    • 2005
  • High quality CdTe single crystal for the solar cell fabrication was grown by vertical Bridgman method. The etch pits patterns of (111) surfaces of CdTe etched by Nakagawa solution was observed the (111)A compesed of Cd atoms with typical triangle etch pits of pyramid mode. From the photoluminescence measurement on (111)A, we observed free exciton ($E_{x}$) existing only high quality crystal and neutal acceptor bound exciton ($A^{0}$,X) having very strong peak intensity. Then, the full width at half maximum and binding energy of neutral acceptor bound exciton were 7 meV and 5.9 meV, respectively. By Haynes rule, an activation enery of impurity was 59 meV. Therefore, the origins on impurity level acting as a neutral acceptor were associated Ag or Cu elements.

Bridgman 방법으로 성장된 CdTe의 광발광 특성 (Photoluminescent properties for CdTe crystal grown by Bridgman method)

  • 홍광준;유상하
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
    • /
    • pp.42-45
    • /
    • 2004
  • High quality CdTe single crystal for the solar cell fabrication was grown by vertical Bridgman method. The etch pits patterns of {111}surfaces of CdTe etched by Nakagawa solution was observed the {111} A composed of Cd atoms with typical triangle etch pits of pyramid mode. From the photoluminescence measurement on {111}A, we observed free exciton($E_x$) existing only higy quality crystal and neytral acceptor bound exciton($A^0$,X) having very strong peak intensity. Then, the full width at half maximum and binding energy of neutral acceptor bound exciton were 7 meV and 5.9 meV, respectively. By Haynes rule, an actibation energy of impurity was 59 meV. Therefore, the origins on impurity level acting as a neutral acceptor were associated Ag or Cu elements.

  • PDF