• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.293-294
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• 2009

The spectral responsivity of solar cells has been measured under high background irradiance using an LED-based differential spectral responsivity Comparator (DSR-C). The comparator developed is fully automated and has some advantages: It does not need a chopper to modulate the light. Unlike the conventional method, it does not require a monochromator to select wavelength. It covers a wavelength range up to 1200 nm. The wavelength range of the comparator is limited by the spectral power distribution of the LEDs and the spectral responsivity of the standard detector. An active temperature control was utilized to meet the specified standard conditions of solar cell test. This work shows the effect of different levels of background irradiance on the spectral responsivity and the importance of same background irradiance for solar cell test as specified by the corresponding standard.

• 한국광학회지
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• 제12권5호
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• pp.376-381
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• 2001

광원의 분광복사휘도를 측정하기 위한 실험 장치를 구성하였으며, PMT, Si, InGaAs a c IR enhanced InGaAs 광검출기의 특성을 평가하였다. 구성된 분광복사휘도 측정 장치의 파장 영역은 250~2500nm이며, 1.0 $\mu$A 이하의 신호에서 비선형 감응도가 0.1% 이하로 선형성이 우수하므로 분광복사휘도의 국가 표준 장치로 사용될 수 있음을 알 숭 있었다.

• 한국광학회:학술대회논문집
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• 한국광학회 2004년도 하계학술발표회
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• pp.282-283
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• 2004

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.348-348
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• 2016

Low dark current (off-current) and high photo current are both essential for a solution processed organic photodetector (OPD) to achieve high photo-responsivity. Currently, most OPDs utilize a bulk heterojunction (BHJ) photo-active layer that is prepared by the one-step deposition of a polymer:fullerene blend solution. However, the BHJ structure is the main cause of the high dark current in solution processed OPDs. It is revealed that the detectivity and spectral responsivity of the OPD can be improved by utilizing a photo-active layer consisting of an interdiffused polymer/fullerene bilayer (ID-BL). This ID-BL is prepared by the sequential solution deposition (SqD) of poly(3-hexylthiophene) (P3HT) and [6,6] phenyl C61 butyric acid methyl ester (PCBM) solutions. The ID-BL OPD is found to prevent undesirable electron injection from the hole collecting electrode to the ID-BL photo-active layer resulting in a reduced dark current in the ID-BL OPD. Based on dark current and external quantum efficiency (EQE) analysis, the detectivity of the ID-BL OPD is determined to be $7.60{\times}1011$ Jones at 620 nm. This value is 3.4 times higher than that of BHJ OPDs. Furthermore, compared to BHJ OPDs, the ID-BL OPD exhibited a more consistent spectral response in the range of 400 - 660 nm.

• Journal of the Optical Society of Korea
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• 제5권1호
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• pp.9-15
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• 2001

The ocean Scanning Multi-spectral Imager (OSMI) is a payload on the KOrea Multi-Purpose SATellite (KOMPSAT) to perform worldwide ocean color monitoring f the study of biological oceanography. OSMI performs solar and dark calibrations for on-orbit instrument calibration. The purpose of the solar calibration is to monitor the degradation of imaging performance for each pixel of 6 spectral bands and to correct the degradation effect on OSMI image during the ground station date processing. The design, the operation concept, and the radiometric characteristics of the solar calibration are investigated. A linear model of image response and a solar calibration radiance model are proposed to study the instrument characteristics using the solar calibration data. The performance of spectral responsivity and spatial response uniformity. The first solar calibration data and the analysis results are important references for further study on the on-orbit stability of OSMI response during its lifetime.

• 한국광학회:학술대회논문집
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• 한국광학회 1989년도 제4회 파동 및 레이저 학술발표회 4th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.230-234
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• 1989

Pyroelectric TGS(triglycine sulfate) detectors, whose thicknesses are 0.1mm and 0.2 mm, are fabricated using the grown TGS crystals from aqueous solution. The outut power and noise from these detectors are measured as a function of chopping frequency in the range from 10Hz to 160Hz with the interval of 10Hz. Response time, responsivity and detectivity are derived from the measured output power and noise of the detectors. The results show that the response time is about 15ms, resposivity is 100V/W at 10Hz and the detectivity at the maximum spectral wavelength D{{{{ lambda }}P* is about 10 cmHz1/2w-1.

• 한국광학회지
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• 제15권5호
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• pp.443-448
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• 2004

국제단위계 중의 하나인 칸델라 눈금을 두 개의 광도계를 사용하여 실현하였다. 광도계의 분광감응도는 광출력을 전기출력으로 치환하여 측정하는 극저온 절대복사계에 소급하여 측정하였다. 광도계 외부에 설치된 정밀 개구는 다이아몬드 회전가공기로 가공하였으며 그 면적은 불확도 0.05%(k = 1) 이내로 측정하였다. 이 광도계를 사용하여 광도 벤치 위에서 1 kW FEL 전구로 칸델라 단위를 실현할 때 불확도를 분광감응도, 감응도의 공간 균일도, 개구 면적, FEL 전구의 색온도와 위치 재현성을 고려하여 평가한 결과 0.25%(k = 1)를 얻었다. 실현한 눈금의 유효성을 확인하기 위하여 미국 NIST의 눈금과 비교한 결과 0.1% 이내에서 일치하였다.

• 한국광학회지
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• 제17권5호
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• pp.391-395
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• 2006

본 논문에서는 온도 제어가 가능한 blackbody를 이용하여 수동형 FTIR 분광계의 radiometric calibration을 수행하고 타당성을 살펴보았다. Radiometric calibration은 분광계로 입사되는 radiance의 온도 변화에 대한 광 검출기의 파장 별 응답특성과 기기 내부에서 발생되는 온도 및 반사율에 의해 발생되는 측정 오차를 보정하여 Planck radiance로 변환하는 기법이다. 시료에 대한 calibration 과정을 수행한 스펙트럼을 spectral library와 비교한 결과, 흡수 스펙트럼의 파장 별 선폭과 상대적인 intensity가 매우 유사하게 나타났으며 입사 광원의 온도차와 비례하여 spectral intensity가 일정하게 증가됨을 확인할 수 있었다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제6권2호
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• pp.119-123
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• 2006

This work presents the fabrication and characteristics of $Bi_2O_3/Si$ heterojunction prepared by rapid thermal oxidation technique without any postdeposition annealing condition. The bismuth trioxide film was deposited onto monocrystalline Si and glass substrates by rapid thermal oxidation of bismuth film with aid of halogen lamp at $500^{\circ}C/\;45$ s in static air. The structural, optical and electrical properties of $Bi_2O_3$ film were investigated and compared with other published results. The structural investigation showed that the grown films are polycrystalline and multiphase (${\alpha}-Bi_2O_3$ and ${\beta}-Bi_2O_3$). Optical properties revealed that these films having direct optical band gap of 2.55 eV at 300 K with high transparency in visible and NIR regions. Dark and illuminated I-V, CV, and spectral responsivity of $Bi_2O_3/Si$ heterojunction were investigated and discussed.

• 센서학회지
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• 제17권5호
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• pp.346-349
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• 2008

A metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector (PD) is proposed as an effective UV sensing device for integration with a GaN n-channel MISFET on auto-doped p-type GaN grown on a silicon substrate. Due to the high hole barrier of the metal-p-GaN contact, the dark current density of the fabricated MSM PD was less than $3\;nA/cm^2$ at a bias of up to 5 V. Meanwhile, the UV/visible rejection ratio was 400 and the cutoff wavelength of the spectral responsivity was 365 nm. However, the UV/visible ratio was limited by the sub-bandgap response, which was attributed to defectrelated deep traps in the p-GaN layer of the MSM PD. In conclusion, an MSM PD has a high process compatibility with the n-channel GaN Schottky barrier MISFET fabrication process and epitaxy on a silicon substrate.