• 산업기술연구
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• 제37권1호
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• pp.27-31
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• 2017

In this paper, we have extended the research on the infrared sensor which has been limited to the plane. The reflection mechanism of the light on the curved surface is analyzed according to the curvature change and the emitted angle of photodiode and verified through experiments. The difference in the curvature causes a difference in the measurement distance, and also changes the intensity of the light coming into the phototransistor, thereby causing a difference in the output voltage. However, the difference in the output voltage due to the curvature change can be solved by adjusting the emitted angle of the photodiode to minimize the spot area formed on the curved surface regardless of the curvature. Therefore, it is possible to measure the distance by using the infrared sensor regardless of the curvature by aligning the photodiode to the center of the curved surface and adjusting the angle of the photodiode.

• Current Optics and Photonics
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• 제5권2호
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• pp.129-133
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• 2021

This study observed the performance of an InAs/GaSb type-II superlattice photodiode with a p-i-n structure for mid-wavelength infrared detection. The 10 ML InAs/10 ML GaSb type-II superlattice photodiode was grown using molecular beam epitaxy. The cutoff wavelength of the manufactured photodiode with Si3N4 passivation on the mesa sidewall was determined to be approximately 5.4 and 5.5 ㎛ at 30 K and 77 K, respectively. At a bias of -50 mV, the dark-current density for the Si3N4-passivated diode was measured to be 7.9 × 10-5 and 1.1 × 10-4 A/㎠ at 77 K and 100 K, respectively. The differential resistance-area product RdA at a bias of -0.15 V was 1481 and 1056 Ω ㎠ at 77 K and 100 K, respectively. The measured detectivity from a blackbody source at 800 K was calculated to be 1.1 × 1010 cm Hz1/2/W at zero bias and 77 K.

• Current Optics and Photonics
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• 제7권2호
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• pp.200-206
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• 2023

Near-infrared (NIR) sensing technology using CMOS image sensors is used in many applications, including automobiles, biological inspection, surveillance, and mobile devices. An intuitive way to improve NIR sensitivity is to thicken the light absorption layer (silicon). However, thickened silicon lacks NIR sensitivity and has other disadvantages, such as diminished optical performance (e.g. crosstalk) and difficulty in processing. In this paper, a pixel structure for NIR sensing using a stacked CMOS image sensor is introduced. There are two photodetection layers, a conventional layer and a bottom photodiode, in the stacked CMOS image sensor. The bottom photodiode is used as the NIR absorption layer. Therefore, the suggested pixel structure does not change the thickness of the conventional photodiode. To verify the suggested pixel structure, sensitivity was simulated using an optical simulator. As a result, the sensitivity was improved by a maximum of 130% and 160% at wavelengths of 850 nm and 940 nm, respectively, with a pixel size of 1.2 ㎛. Therefore, the proposed pixel structure is useful for NIR sensing without thickening the silicon.

• 센서학회지
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• 제8권3호
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• pp.239-246
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• 1999

MOCVD로 성장된 p-i-n 구조의 InSb 웨이퍼를 이용하여 $3{\sim}5\;{\mu}m$ 영역의 적외선을 감지할 수 는 고감도 광기전력 형태의 적외선 광다이오드를 제조하였다. InSb는 녹는점과 표면원자들의 증발온도가 낮기 때문에 광다이오드의 접합계면과 표면의 절연보호막으로 $SiO_2$ 박막을 원격 PECVD를 이용하여 성장시켰다. 광다이오드의 저항성 접촉을 위해 In을 증착하였고 77K의 암상태에서 전류-전압 특성을 조사하였다. 영전위 저항과 수광면적의 적($R_0A$)이 $1.56{\times}10^6\;{\Omega}{\cdot}cm^2$의 높은 값을 가졌는데 이는 BLIP 조건을 만족하는 높은 값이었다. InSb 광다이오드에 적외선을 입사 했을때 $10^{11}\;cm{\cdot}Hz^{1/2}{\cdot}W^{-1}$의 매우 높은 정규화된 검지도를 나타내었다. 높은 양자효율과 검지도로 인해 제조된 InSb 적외선 단위 셀을 적외선 array에 그 적용이 가능할 것으로 보인다.

• 분석과학
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• 제20권4호
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• pp.289-295
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• 2007

사각파형 벗김 전압 전류법과 순환 전압 전류법에서 적외선 광 다이오드의 간단한 전자 회로를 사용한 철의 정량을 연구하였다. 기존에 사용되는 작업 전극과 최적 분석 조건을 비교하였으며, 순환 전압 전류법의 결과는 보다 간단하며 정밀하였으며, 최적 조건에서 농도 범위는 0.1-0.8과 0.85-6.0 mg/L 이었다, 0.4 mg/L의 철 농도에서 15번 반복 측정한 상대 표준편차는 0.09%였으며, 최소 분석 검출 한계는 $80{\pm}0.6{\mu}g/L$ 였다, 이결과는 폐수중의 철 정량에 응용하였다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1993년도 춘계학술대회
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• pp.116-119
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• 1993

In this paper, we implemented a pulse wave type oximeter system that continuously measure the of oxyhemoglobin saturation of the arterial blood(SaO2) and pulse rate with non-invasively. We use the transmission type and reflection type transducer for comparison the percentage of hemoglobin oxgen saturation. The light Iron the two kind of LEDs is transmitted through the tissue, then received by a single photodiode with alternatively. By the phase sensitive detection circuit, the output of the photodiode is separated in to red and near infrared signal. We calculated a ratio of light transmittance between two kind of LEDs, and then, it is applied to the oxgen saturation coefficent calculation formular.

• 한국전자통신학회논문지
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• 제9권5호
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• pp.555-560
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• 2014

본 논문에서 850nm~1000nm 파장대역에서 레이저를 검출하기 위한 고감도 실리콘 포토다이오드를 제조하고 전기적 및 광학적 특성을 분석하였다. 소자의 크기는 $5000{\mu}m{\times}2000{\mu}m$이며 두께는 $280{\mu}m$로 제조하여 TO-5 형태로 패키징 하였다. 전기적 특성으로 암전류는 5V 역 전압 일 때 0.1nA의 값을 나타내었으며 정전용량은 0V일 때 1kHz 주파수 대역에서 32.5pF와 200kHz 주파수 대역에서 32.4pF로 적은 정전용량의 값을 나타내었다. 또한 출력신호의 상승시간은 10V의 전압일 때 20.92ns로 고속 응답특성을 확인하였다. 광학적 특성으로는 890nm에서 최대 0.57A/W의 분광감응도를 나타내었고 1000nm에서는 0.37A/W로 감소한 분광감응도를 나타내고 있지만 870nm~920nm 파장대역에서는 비교적 우수한 분광감응도를 나타내었다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.3115-3115
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• 2001

In this study, portable near infrared (NIR) system was newly integrated with a photodiode array detector, which has no moving parts and this system has been successfully applied for evaluation of human skin moisture. The good correlation between NIR absorbance and absolute water content of separated hairless mouse skin was, in vitro, showed depending on the water content (7.42-84.94%) using this portable NIR system. Partial least squares (PLS) regression was used for the calibration with the 1100-1650 nm wavelength range. For the practical use for the evaluation of human skin based on moisture, PLS model for human skin moisture was, in vivo, developed using the portable NIR system based on the relative water content values of stratum corneum from the conventional capacitance method. The PLS model showed a good correlation. This study indicated that the portable NIR system could be a powerful tool for human skin moisture, which may be much more stable to environmental conditions such as temperature and humidity, compared to conventional methods. Furthermore, in order to confirm the performance of newly integrated portable NIR system, scanning type conventional NIR spectrometer was used in the same experiments and the results were compared.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1967-1969
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• 2003

본 논문에서는 무인 주행 저속 전기 자동차 시스템 개발을 위한 적외선 LED 라인트레이서를 제작하였다. 햇빛에 의한 영향을 제거하기 위해 적외선 LED를 펄스(pulse)로 구동시켰으며 흰색선에서 반사된 적외선 신호를 photodiode를 이용하여 감지하였다. 감지된 신호는 증폭단과 Peak Detector를 거쳐 최종적으로 AVR MCU로 입력이 된 후 여러 상황에 따른 차량의 방향을 결정할 수 있도록 알고리즘를 통해 처리하였다. 실험을 통하여 본 논문에서 제작한 라이트레이서 모듈이 원하는 방향으로 동작함을 확인하였다.

• Toxicological Research
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• 제33권2호
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• pp.135-140
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• 2017

The cobalt (Co(II)) ion is a main component of alloys and considered to be carcinogenic, especially due to the carcinogenic and toxicological effects in the aquatic environment. The toxic trace of the Co(II) detection was conducted using the infrared photodiode electrode (IPDE) using a working electrode, via the cyclic and square-wave anodic stripping voltammetry. The results indicated a sensitive oxidation peak current of Co(II) on the IPDE. Under the optimal conditions, the common-type glassy carbon, the metal platinum, the carbon paste, and the carbon fiber microelectrode were compared with the IPDE in the electrolyte using the standard Co(II). The IPDE was found to be far superior to the others.