• Title/Summary/Keyword: photoelectric

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From Two- To Three-Dimensional Molecular Assemblies for Photoelectric Conversion

  • Yamada, Sunao;Nitahara, Satoshi
    • Journal of Photoscience
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    • v.11 no.1
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    • pp.1-6
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    • 2004
  • Molecular assembling is one of the current interests in the field of bottom-up nanotechnology. Self-assembled monolayers of sulfur-containing molecules or supramolecular assemblies via surface sol-gel processes formed on conductive supports are chemically robust and can be easily fabricated without sophisticated instruments. We have fabricated various types of molecular assemblies consisting of donor-acceptor pairs on the surfaces of gold and indium-tin-oxide electrodes. Build-up of three-dimensional multi structures consisting of thiol dyes and gold nanoparticles also has been successful. These assemblies showed clear photocurrent responses in photoelectro-chemical cells. In this article, we will describe recent progress on photoelectric conversion using molecular assemblies especially focused on our research results.

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CRT Color Transform to CIELab Color System using RGB Image Data (RGB 화상테이터를 이용한 CRT 표현색의 CIELab 표색계로의 변화에 관한 연구)

  • 안석출
    • Journal of the Korean Graphic Arts Communication Society
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    • v.13 no.1
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    • pp.73-91
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    • 1995
  • Spectroscopic and Photoelectric Characteristics in the Cyanine and Merocyanine Dye according to systematically change of their structures were experimentally discussed. As result, in solution, Hetero atoms(X) of Cyanine and Merocyanine dye were participated in resonance X of d obital rather than X of pobital,effected in resonance and contributed in extension of conjugated system. in solid film,new spectra,called eximer-fluorenscence,were appeared in 3-dimensional fluorenscence of high density of Cyanine dye but not of Merocyanine. The activational energy of conductivity in Merocyanine dye was lower than in cyanine, an the contrary,the drift mobility was higher and the former in photoelectric characteristics was more effec-tive than the latter. In this paper,authors invertigated the changes of dye structure by molecular obital method to confirm the results of spectroscopic and photoelectric characteristics in the Cyanine and Merocyanine Dye acco-rding to systematically cally change of their structure, and counted total energy on dihedral angle and dipol miments if dyes in S0 and S1.

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MoOx/Si Heterojunction for High-Performing Photodetector (MoOx 기반 실리콘 이종접합 고성능 광검출기)

  • Park, Wang-Hee;Kim, Joondong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.11
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    • pp.720-724
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    • 2016
  • Transparent n-type metal-oxide semiconductor of $MoO_x$ was applied on a p-type Si substrate for high-performing heterojunction photodetector. The formation of $MoO_x$ on Si spontaneously established a rectifying current flow with a high rectification ratio of 1,252.3%. Under light illumination condition, n-type $MoO_x$/p-type Si heterojunction device provided significantly fast responses (rise time : 61.28 ms, fall time : 66.26 ms). This transparent metal-oxide layer ($MoO_x$) would provide a functional route for various photoelectric devices, including photodetectors and solar cells.

The Unipolar Charging Characteristics of Submicron Particles by Using an Indirect Photoelectric Charging (간접 광대전에 의한 서브 마이크론 입자의 단극하전 특성)

  • Choi, Young-Joo;Kim, Sang-Soo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.6
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    • pp.677-684
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    • 2003
  • A new unipolar aerosol charger was developed by using an indirect photoelectric charging. The charger consists of two coaxial tubes, the inner UV lamp wrapped with stainless mesh and the outer Al cylinder. In this study, the effects of flow rate, particle size, and electric field were examined to search the optimal charging conditions with experimental and numerical methods. Monodisperse NaCl particles were fed into an annular space and the particles were charged by negative ions generated from Al plate exposed to the UV light. According to experimental results, the average number of elementary charge on particles increases from 2.5 to 5.5 as particle size increases from 50nm to 130nm at 2.5 L/min and 100V. The average number of elementary charge on particles was maximized at 25V as the electric potential between the stainless mesh and Al plate was varied from 0V to 400V.

Hybrid Transparent Conductor by using Solution-Processed AgNWs for High-Performing Si Photodetectors

  • Kim, Hong-Sik;Kim, Joondong
    • Current Photovoltaic Research
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    • v.3 no.4
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    • pp.116-120
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    • 2015
  • A hybrid transparent conducting layer was applied for Si photodetector. To realize the hybrid transparent conducting layer, a 200 nm-thick ITO layer was deposited onto a Si substrate, following by a solution-processed AgNWs-coating on the ITO. The hybrid transparent conducting layer showed an excellent low electric resistance of $15.9{\Box}/{\Omega}$ with a high optical transparency of 86.89%. Due to these optical and electrical benefits, the hybrid transparent conductor-embedding Si diode provides an extremely high rectifying ratio of 3386. Under light-illumination, the hybrid transparent conductor device provides extremely high photoresponses for broad wavelengths. This implies that a functional design for hybrid transparent conductor is crucial for photoelectric devices and applications.

Measurement and Interpretation of Undergraduate Students' Writing about the Experiments of the Photoelectric Effect

  • Jho, Hunkoog;Ji, Youngrae
    • New Physics: Sae Mulli
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    • v.68 no.11
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    • pp.1231-1239
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    • 2018
  • This study aimed at examining undergraduate students' writing about experiments related to the photoelectric effect and giving some implications for experiment education. Thus, this study analyzed 26 students' reports about three kinds of experiments: measuring Planck's constant, comparing the photocurrent and the photovoltage across the intensity of light, and comparing the photocurrent and the photovoltage across the frequency of light. In the measurements, less than 25% of the students expressed the data to the correct number of significant figures even though two-thirds of the students successfully obtained the data given in the manual. In terms of interpretation, the students were not aware of the physical meanings of the detailed parts in the graphs. Even though over 50% of the students drew a line relating photocurrent to voltage, no students compared the theoretical to the empirical data or made a judgment as to whether of not the background theory really fit the experiment. The research findings showed that insufficient knowledge and skills for physics inquiry may be an obstacle in performing the experiments well.

Feasibility Study on a Defrost Control Method by Using a Photoelectric Sensors (광센서를 이용한 제상제어 방법에 대한 타당성 검토)

  • Jeon, Chang-Duk;Kim, Dong-Seon;Lee, Seung-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.6
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    • pp.3389-3395
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    • 2014
  • Conventional methods, such as the clock time control method and temperature difference control method, for defrost control often encounter mal-defrost and a waste of energy. Therefore, a more efficient method is needed to control defrosting precisely. A photoelectric sensor unit consisting of an emitter and a collector was installed in the front of outdoor heat exchanger. Accurate defrost control was performed by monitoring and using the change in output voltage according to the presence of frost. In this study, experiments were performed to determine if the performance and characteristic curves obtained using the clock time control method can be reproduced using a photoelectric sensor under the heating and defrosting capacity test condition described at KS C 9306. The output voltage of the phototransistor (receiver) and heating capacity, power consumption, and surface temperature of the outdoor heat exchanger, were compared. The results showed that photoelectric sensors can be used as a defrost control method. On-off control timing of the clock time defrosting method was in good agreement with those predicted by the output voltage of the photoelectric sensor.

Photoelectric Characteristics of a-Si:H Thin Film Transistor by Spectral Properties of Various Backlight Sources

  • Choi, Kyung-Min;Kwon, Sang-Jik;Cho, Eou-Sik
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.572-575
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    • 2008
  • Photo leakage characteristics of a-Si:H TFT were obtained for the illuminations from various backlight sources and the results were compared and analyzed in terms of the photoelectric properties of light. The analysis shows that the photocurrents are related to the wavelengths of the peak intensities of the spectrums of light sources.

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A Study on the Digital Printing Devices for the Output System of the Photoelectric Photometry (광전(光電) 측광(測光) 결과(結果)의 계수(計數) 프린트 장치(裝置) 연구(硏究))

  • Kang, Yong-Hee
    • The Bulletin of The Korean Astronomical Society
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    • v.6
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    • pp.3-6
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    • 1981
  • A scheme for installing the digital printing devices as an additional output system of photoelectric photometry is discussed. The digital printing devices consist of counter/integrator and printer interfaces for the digital printer HP 5055A. The integration gate time could be adjusted from 1 second to 99 seconds.

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Development of a Multi-Channel Photoelectric Photometer Using Optical Fiber

  • Lee, W.B.;Kim, H.I.;E.C.Sung;Moon, I.K.
    • Bulletin of the Korean Space Science Society
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    • 1992.10a
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    • pp.231-238
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    • 1992
  • We have developed a proto-type four-channel photoelectric photometer and control software for the 61-cm reflector of the Sobaeksan Astronomy Observatory. The photometer consists of five main units which has a manipulator, a set of four-opticsassemblies, a light detection units, Pulse counting electronics and a host computer. The software to control the chopper, filter wheel and photon counter has also been developed..

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