• Title/Summary/Keyword: HgTe

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Opto-electrical properties for a HgCdTe epilayers grown by hot wall epitaxy (Hot wall epitaxy에 의해 성장된 HgCdTe 에피레이어의 광전기적특성)

  • 홍광준
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.11a
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    • pp.152-152
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    • 2003
  • Hg$\sub$l-x/Cd$\sub$x/Te (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 $\mu\textrm{m}$ 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

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Binding energy study from photocurrent signal in HgCdTe layers

  • Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.379-379
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    • 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.

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The electron density distribution and the structure of semiconductor HgCdTe (반도체 HgCdTe의 전자 밀도 분포와 결정 구조)

  • Kook-Sang Park;Ky-Am Lee
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.4 no.4
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    • pp.388-394
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    • 1994
  • A Hg(0.79)Cd(0.21)Te single crystal has been grown by the Traveling Heater Method(THM). Its zinc blend cubic structure is identified from the X-ray diffraction patterns and its lattice constant is determined to be $6.464 {\AA}$ using the least-square method of Cohen. From the values of the lattice constant, the composition x is determined to be 0.21. The electron density is calculated from the relative intensities of the scattered X-ray and compared with the theoretically calculated values. From the electron density distribution, it is shown that the crystal binding of Hg(1-x)Cd(x)Te(MCT) is mainly covalent and has tetrahedron bonds between adjacent atoms.

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Tunneling Current Calculation in HgCdTe Photodiode (HgCdTe 광 다이오드의 터널링 전류 계산)

  • 박장우;곽계달
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.9
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    • pp.56-64
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    • 1992
  • Because of a small bandgap energy, a high doping density, and a low operating temperature, the dark current in HgCdTe photodiode is almost composed of a tunneling current. The tunneling current is devided into an indirect tunneling current via traps and a band-to-band direct tunneling current. The indirect tunneling current dominates the dark current for a relatively high temperature and a low reverse bias and forward bias. For a low temperature and a high reverse bias the direct tunneling current dominates. In this paper, to verify the tunneling currents in HgCdTe photodiode, the new tunneling-recombination equation via trap is introduced and tunneling-recombination current is calculated. The new tunneling-recombination equation via trap have the same form as SRH (Shockley-Read-Hall) generation-recombination equation and the tunneling effect is included in recombination times in this equation. Chakrabory and Biswas's equation being introduced, band to band direct tunneling current are calculated. By using these equations, HgCdTe (mole fraction, 0.29 and 0.222) photodiodes are analyzed. Then the temperature dependence of the tunneling-recombination current via trap and band to band direct tunneling current are shown and it can be known what is dominant current according to the applied bias at athe special temperature.

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$Hg_1_xCd_xTe$를 이용한 적외선 검지소자기술

  • Maeng, Seong-Jae;Lee, Jae-Jin;Kim, Jin-Seop
    • Electronics and Telecommunications Trends
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    • v.3 no.4
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    • pp.45-56
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    • 1988
  • 적외선검출기용 반도체소자($Hg_1_xCd_xTe$)의 특성 및 응용에 대하여 조사하고, 국외의 연구현황과 국내의 문제점 및 향후 전망에 대하여 기술하였다. $Hg_1_xCd_xTe$는 조성에 따라 검지기 파장영역을 조절할 수 있으며, 그 자체에 검지부와 신호처리부를 집적할 수 있는 monolithic기술이 유망하여 앞으로 중요한 반도체중의 하나로 확립될 것이다.

Numerical analysis of HgCdTe heterojunction photodiodes (HgCdTe 이종접합 광다이오드의 수치 해석)

  • 조남홍;곽규달
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.7
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    • pp.45-55
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    • 1997
  • Electircal characteristics of HgCdTe photodiodes with a heterostructure to achieve high performance are analyzed numerically. A two-dimensional device simulator which can handle a HgCdTe heterostructure, was developed for this work. The effects of band nonparabolicity, carrier degeneracy, and band-offset of heterointerace are included in a carrier transport model. A unified generation-recombination model includes simultaneously phonon-assisted tunneling and pure tunneling of carriers via traps is newly employed for describing the electric field and temperature dependency of dark current effectively. Furthermore, to accurately predict the effect mole fraction variations on genration rates, ray-trace algorithm is incorporated in the our simulator. Under the various circumstances such as dark, illumination, and surface states, electrical properties of planar heterostructure photodiode are presented and those of homojunction are compared. These results serve as a explanation of cap layer's role on performance.

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Inorganic Flexible Thin Film Transistor with HgTe Nanocrystals (HgTe 나노입자를 이용한 무기물 플렉시블 박막 트랜지스터)

  • Jang, Jae-Won;Cho, Kyoung-Ah;Kim, Sang-Sig
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1341-1342
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    • 2007
  • Poly-ether-sulphone (PES) 기판위에 열처리 공정을 거친 HgTe 나노입자를 이용하여 플렉시블 투명 박막 트랜지스터를 제작하였다. 활성층으로 사용된 HgTe 나노입자층은 UV/ozone 처리로 친수성화 된 PES 기판위에 스핀코팅으로 형성되었다. 제작된 박막 트랜지스터는 전형적인 p형 트랜지스터 특성을 보여주었으며, PES 기판에 스트레인을 가하지 않은 상태에서는 164의 전류점멸비와 1.6 $cm^{2}/Vs$ 의 전하 이동도가 계산되었고, PES 기판에 2.0%의 스트레인을 인가하였을 때에는 266의 전류점멸비와 1.0 $cm^2/Vs$ 의 전하 이동도가 계산되었다.

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