• Title, Summary, Keyword: Semiconductor detector

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EFFECT OF METAL CONTACT ON THE CZT DETECTOR PERFORMANCE

  • Park, Se-Hwan;Park, Hyung-Sik;Lee, Jae-Hyung;Kin, Han-Soo;Ha, Jang-Ho
    • Journal of Radiation Protection and Research
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    • v.34 no.2
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    • pp.65-68
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    • 2009
  • Metal-semiconductor contact is very important for the operating property of semiconductor detector. $Cd_{0.96}$ $Zn_{0.04}$ Te semiconductor crystal was grown with Bridgman method, and the crystal was cut and polished. EPMA (Electron Probe Micro Analyzer) and ICP-MS (Inductively Coupled Plasma Mass Spectrometry) analysis were done to obtain the chemical composition and impurity of the crystal. Metal contact was deposited with thermal evaporator on both sides of the crystal. Detectors with Au/CZT/Au and In/CZT/Au structure were made, and I-V curve and the energy spectrum were measured with the detectors. It could be seen that the detector with the In/CZT/Au structure has superior property than the detector with Au/CZT/Au structure when the crystal resistivity was low. However, the metal contact structure effect becomes low when the crystal resistivity was high.

Development of Fast-Response Portable NDIR Analyzer Using Semiconductor Devices

  • Kim, Woo-Seok;Lee, Jong-Hwa;Park, Young-Moo;Yoo, Jai-Suk;Park, Kyoung-Seok
    • Journal of Mechanical Science and Technology
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    • v.17 no.12
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    • pp.2099-2106
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    • 2003
  • In this paper, a novel fast response NDIR analyzer (FRNDIR), which uses an electrically pulsed semiconductor emitter and dual type PbSe detector for the PPM-level detection of carbon dioxide (CO$_2$) at a wavelength of 4.28 $\mu\textrm{m}$, is described. Modulation of conventional NDIR energy typically occurs at 1 to 20 Hz. To achieve real time high-speed measurement, the new analyzer employs a semiconductor light emitter that can be modulated by electrical chopping. Updated measurements are obtained every one millisecond. The detector has two independent lead selenide (PbSe) with IR band pass filters. Both the emitter accuracy and the detector sensitivity are increased by thermoelectric cooling of up to -20 degrees C in all semiconductor devices. Here we report the use of semiconductor devices to achieve improved performance such that these devices have potential application to CO$_2$ gas measurement and, in particular, the measurement of fast response CO$_2$ concentration at millisecond level.

A Study on the Optimum Design of Charge Pump PLL for High Speed and Fast Acquisition (고속동작과 빠른 Acquisition 특성을 가지는 Charge Pump PLL의 최적설계에 관한 연구)

  • Woo, Young-Shin;Sung, Man-Young
    • Proceedings of the KIEE Conference
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    • pp.718-720
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    • 1999
  • This paper describes a charge pump PLL architecture which achieves high frequency operation and fast acquisition. This architecture employs multi-phase frequency detector comprised of precharge type phase frequency detector and conventional phase frequency detector. Operation frequency is increased by using precharge type phase frequency detector when the phase difference is small and acquisition time is shortened by using conventional phase frequency detector and increased charge pump current when the phase difference is large. By virtue of this multi-phase frequency detector structure, the maximum operating frequency of 694MHz at 3.0V and faster acquisition were achieved by simulation.

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Radiation Damage of SiC Detector Irradiated by High Dose Gamma Rays

  • Kim, Yong-Kyun;Kang, Sang-Mook;Park, Se-Hwan;Ha, Jang-Ho;Hwang, Jong-Sun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.87-90
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    • 2006
  • Two SiC radiation detector samples were irradiated by Co-60 gamma rays. The irradiation was performed with dose rates of 5 kGy/hour and 15 kGy/hour for 8 hours, respectively. Metal/semiconductor contacts on the surface were fabricated by using a thermal evaporator in a high vacuum condition. The SiC detectors have metal contacts of Au(2000 ${\AA}$)/Ni(300 ${\AA}$) at Si-face and of Au(2000 ${\AA}$)/Ti(300 ${\AA}$) at C-face. I-V characteristics of the SiC semiconductor were measured by using the Keithley 4200-SCS parameter analyzer with voltage sources included. From the I-V curve, we analyzed the Schottky barrier heights(SBHs) on the basis of the thermionic emission theory. As a result, the 6H-SiC semiconductor showed- similar Schottky barrier heights independent to the dose rates of the irradiation with Co-60 gamma rays.

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Relation Between Flat-band Voltage and Quantum Efficiency of InSb MWIR Detector (InSb 중적외선 검출기의 Flat-band 전압과 양자효율의 상관관계)

  • Kim, Young-Chul;Eom, JunHo;Jung, Han;Kim, SunHo;Kim, NamHwan;Kim, Young-Ho
    • Journal of the Semiconductor & Display Technology
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    • v.17 no.2
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    • pp.12-15
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    • 2018
  • InSb (III-V compound semiconductor) is used for photodiode to detect the mid-wavelength infrared radiation. Generally the quantum efficiency of InSb IR FPAs(Focal Plane Arrays) is known to be determined by thickness of InSb and transmittance of anti-reflection coating layer. In this study, we confirmed that the C-V characteristics of detector array affects the quantum efficiency of the InSb IR FPAs. We fabricated the IR FPAs with various $V_{fb}$(flat band voltage) values and confirmed the tendency between the $V_{fb}$ value and quantum efficiency of the IR FPAs.

Evaluation of a Fabricated Charge Sensitive Amplifier for a Semiconductor Radiation Detector

  • Kim, Han-Soo;Ha, Jang-Ho;Park, Se-Hwan;Lee, Jae-Hyung;Lee, Cheol-Ho
    • Journal of Radiation Protection and Research
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    • v.35 no.2
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    • pp.81-84
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    • 2010
  • A CSA(Charge Sensitive Amplifier) was designed and fabricated for application in a radiation detection system based on a semiconductor detector such as Si, SiC, CdZnTe and etc.. A fabricated hybrid.type CSA was evaluated by comparison with a commercially available CSA. A comparison was performed by using calculation of ENC (Equivalent Noise Charge) and by using energy resolutions of fabricated radiation detectors based on Si. In energy resolution comparison, a fabricated CSA showed almost the same performance compared with a commercial one. In this study, feasibility of a fabricated CSA was discussed.

Development and Application of the Semiconductor Neutron Radiation Detector (반도체 중성자 탐지소자 개발 및 응용)

  • Lee, Nam-Ho;Lee, Hong-Kyu;Youk, Young-Ho
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.2
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    • pp.299-304
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    • 2011
  • In this paper, we developed the semiconductor neutron radiation detector and the multi-purpose radiation detection technologies for the next generation military personal surveymeter. The PIN type semiconductor neutron detector and the prototype measure the neutron radiation dose upto 1,000cGy with ${\pm}20%$ error. It also have a good performance about the Gamma, Alpha and Beta radiation and MIL-STD-810F.

Implementation of Electronic Personal Dosimeter Using Silicon PIN Photodiode (실리콘 핀 포토다이오드를 이용한 능동형 방사선 피폭 전자선량계의 구현)

  • 이운근;백광렬;권석근
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.4
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    • pp.296-303
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    • 2003
  • A personal portable type electronic dosimeter using silicon PIN photodiode and small GM tube is recently attracting much attention due to its advantages such as an immediate indication function of dose and dose rate, alerting function, and efficient management of radiation exposure history and dose data. We designed and manufactured a semiconductor radiation detector aimed to directly measure X-ray and v-ray irradiated in silicon PIN photodiode, without using high-priced scintillation materials. Using this semiconductor radiation detector, we developed an active electronic dosimeter, which measures the exposure dose using pulse counting method. In this case, it has a shortcoming of over-evaluating the dose that shows the difference between the dose measured with electronic dosimeter and the dose exposed to the human body in a low energy area. We proposed an energy compensation filter and developed a dose conversion algorithm to make both doses indicated on the detector and exposed to the human body proportional to each other, thus enabling a high-precision dose measurement. In order to prove its reliability in conducting personal dose measurement, crucial for protecting against radiation, the implemented electronic dosimeter was evaluated to successfully meet the IEC's criteria, as the KAERI (Korea Atomic Energy Research Institute) conducted test on dose indication accuracy, and linearity, energy and angular dependences.