• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 기술교육위원회 창립총회 및 학술대회 의료기기전시회
• /
• pp.52-59
• /
• 2001

The photoluminescence and the photo-current from p-type GaN films were investigated on both room- and low-temperatures for various Mg doping concentrations. At a low Mg doping level, there exists a photoluminescence center of the donor and the acceptor pair transition of the 3.28-eV band. This center is correlated with the defects for a shallow donor of the VGa and for an acceptor of MgGa. The acceptor level shows the binding energy of 0.2-0.25 eV, which was observed by the photon energy of the photo-current signal of 3.02-3.31 eV. At a high Mg doping level, there is a photoluminescence center of a deep donor and an acceptor pair transition of the 2.76-eV blue band. This center is attributed to the defect structures of MgGa-VN for the deep donor and MgGa for the acceptor. For low. doped samples, thermal annealing provides an additional photo-current signal for an unoccupied deep acceptor levels of 0.87-1.35 eV above valence band, indicating the p-type activation.

• 한국전기전자재료학회논문지
• /
• 제17권4호
• /
• pp.404-409
• /
• 2004

We fabricated photo-sensor for fluorescence detection in LOC. LOC is high throughput screening system. Our LOC screens biochemical reaction of protein using the immunoassay, and converts biochemical reaction into electrical signal using LIF(Laser Induced Fluorescence) detection method. Protein is labeled with rhodamine intercalating dye and finger PIN photodiode is used as photo-sensor We measured fluorescence emission of rhodamine dye and analyzed tendency of fluorescence detection, according to photo-sensor size, light intensity, and rhodamine concentration. Detection current was almost linearly proportional to two parameters, intensity and concentration, and was inversely proportional to photo-sensor size. Integrated LOC consists of optical-filter deposited photo-sensor and PDMS microchannel detected 50 (pg/${mu}ell$) rhodamine. For integrated LOC including light source, we used green LED as the light source and measured emitted fluorescence.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.10-11
• /
• 2006

The azobenzene dendrimer is one of the dendrimeric macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and photoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current. Functional photoisometrization organic molecular the photo-stimulus to organic monomolecular L films and LB films of dendrimer and SASH were performed. The SASH organic monolayer in case of pressure stimulus occurred that positive course but in case of the photo-stimulus compared positive and negative. It is assumed that generation forms of displacement current were measured when photo-stimulus for impression.

• 한국전기전자재료학회논문지
• /
• 제27권11호
• /
• pp.746-752
• /
• 2014

Photo electrode is an important component of DSSC, so this paper did some research on it. Through the method of adding PEG additive into $TiO_2$ paste, the electrical characteristics and efficiencies of DSSCs with photo electrode surface area were studied. In the case of not adding PEG in $TiO_2$ paste, $26{\mu}m$ thickness $TiO_2$ photo electrode shows 5.081% efficiency. The highest short circuit current density was $10.476mA/cm2^$. The structure of porous $TiO_2$ film can be controlled through changing the PEG additive amount in $TiO_2$ paste and the molecular weight of PEG. When the additive amount of PEG 20,000 in $TiO_2$ paste reaches 5%, the peak efficiency with $26{\mu}m$ thickness $TiO_2$ photo electrode was 5.387% and its highest current density were $11.084mA/cm^2$.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제15권1호
• /
• pp.35-40
• /
• 2015

In this study, an n-ZnO/p-Si heterojunction diode with embedded Ag nanoparticles was fabricated to investigate the possible improvement of light trapping via the surface plasmon resonance effect for solar cell applications. The Ag nanoparticles were fabricated by the physical sputtering method. The acquired current-voltage curves and optical absorption spectra demonstrated that the application of Ag nanoparticles in the n-ZnO/p-Si interface increased the photo current, particularly in specific wavelength regions. The results indicate that the enhancement of the photo current was caused by the surface plasmon resonance effect generated by the Ag nanoparticles. In addition, minority carrier lifetime measurements showed that the recombination losses caused by the Ag nanoparticles were negligible. These results suggest that the embedding of Ag nanoparticles is a powerful method to improve the performance of n-ZnO/p-Si heterojunction solar cells.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
• /
• pp.956-958
• /
• 1999

We designed and fabricated p-type MOSFETs with floating gate in n-type well lesion and examined their photo characteristics. The fabricated MOBFETs showed a high photo-respsonse characteristics, indicating a possibility as a photo sensor. The structures of MOSFETs were changed as to the number of gate and channel. As the number of channel increased, the induced current by light source s increased. However, the effect of the number of gate was negligble on the photo-response characteristics of the device.

• Journal of information and communication convergence engineering
• /
• 제5권2호
• /
• pp.116-120
• /
• 2007

In this paper, the image sensor using the a-Si:H TFT is proposed. The optimum amorphous silicon thin film is deposited using plasma enhanced chemical vapor deposition (PECVD). TFT and photodiode both with the thin film are fabricated and form image sensor. The photodiode shows that $I_{dark}\;is\;{\sim}10^{-13}\;A,\;I_{photo}\;is\;{\sim}10^{-9}\;A\;and\;I_{photo}/I_{dark}\;is\;{\sim}10^4$, respectively. In the case of a-Si:H TFT, it indicates that $I_{on}/I_{off}\;is\;10^6$, the drain current is a few ${\mu}A\;and\;V_{th}\;is\;2{\sim}4$ volts. For the analysis on the fabricated image sensor, the reverse bias of -5 volts in ITO of photodiode and $70 {\mu}sec$ pulse in the gate of TFT are applied. The image sensor with good property was conformed through the measured photo/dark current.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제50권1호
• /
• pp.17-22
• /
• 2001

The floating-gate MOSFETs were fabricated by employing 1.5 m n-well CMOS process and their optical-electrical properties were characterized for the application to CMOS image sensor system. Based on the simulation of energy band diagram and operating mechanism of parasitic BJT were proposed as solutions for the increase of photo-current value. In order to realize them, MOSFETs having multi-gate and channel structures were fabricated and 60% increase in photo-current was achieved through enlargement of depletion layer and parallel connection of parasitic BJTs by channel division.

• 센서학회지
• /
• 제21권5호
• /
• pp.339-344
• /
• 2012

This article describes a novel method for the detection of amyloid-${\beta}$($A{\beta}$) peptide that utilizes a photo-sensitive field-effect transistor (p-FET). According to a recent study, $A{\beta}$ protein has been known to play a central role in the pathogenesis of Alzheimer's disease (AD). Accordingly, we investigated the variation of photo current generated from p-FET with and without intracellular magnetic beads conjugated with $A{\beta}$ peptides, which are placed on the p-FET sensing areas. The decrease of photo current was observed due to the presence of the magnetic beads on the channel region. Moreover, a similar characteristic was shown when the Raw 264 cells take in magnetic beads treated with $A{\beta}$ peptide. This means that it is possible to simply detect a certain protein using magnetic beads and a p-FET device. Therefore, in this paper, we suggest that our method could detect tiny amounts of $A{\beta}$ for early diagnosis of AD using the p-FET devices.

• 한국진공학회지
• /
• 제22권4호
• /
• pp.193-197
• /
• 2013

본 연구에서는 sol-gel법을 이용해 제작된 $VO_2$ 박막의 광전변환 특성을 연구하기 위해 광 조사 유무에 의해 생성되는 전류를 bias voltage에 따라 온도별로 측정하였다. 그 결과, 광 조사 유무에 따라 박막에서 생성되는 전류가 변화되는 것을 알 수 있었으며, bias voltage가 증가할수록 전류가 일정하게 늘어나는 것을 알 수 있었다. 특히, 광에 의해 생성되는 전류는 $VO_2$에서의 MIT 온도보다 낮은 $50^{\circ}C$에서 최대였다. 이러한 결과는 $VO_2$에서 photo-voltaic 효과가 발생함을 의미하며, 따라서 $VO_2$ 박막을 광전변환 소자로 응용할 수 있을 것으로 기대된다.