• 한국자기학회:학술대회 개요집
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• 한국자기학회 2003년도 somma/kms meeting
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• pp.342-342
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• 2003

• 한국광학회:학술대회논문집
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• 한국광학회 1991년도 제6회 파동 및 레이저 학술발표회 Prodeedings of 6th Conference on Waves and Lasers
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• pp.29-34
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• 1991

An optoelectronic implementation of analog and non-volatile synaptic weights of neural networks is proposed by using the doping modulated amophous silicon multilayer. The persistent photoconductivity(PPC) of the multilayer induced by a short illumination is characterized in experiment and implemented to the non-volatile synaptic weights. An optoelectronic processor with the single layer perceptron algorithm is also proposed. Some learning equations of the processor and the results of simulation are presented.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1998년도 IUMRS-ICEM ABSTRACT BOOK
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• pp.113.3-113
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• 1998

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1998년도 PROCEEDINGS OF THE 14TH KACG TECHNICAL MEETING AND THE 5TH KOREA-JAPAN EMGS (ELECTRONIC MATERIALS GROWTH SYMPOSIUM)
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• pp.39-43
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• 1998

Single crystals of{{{{ { Zn}_{ 1-x} {Mn }_{x }{Te} }}}} with x=0.3-0.6 were prepared by the standard Bridgeman method. Diffuse neutron diffraction intensities due to the short range magnetic ordering is found in the vicinities of 1 1/2 0 reciprocal point and its equivalent point, indicating that the magnetic correlation of the clusters is the type III antiferromangetic one do the F-type Bravais class crystals, being identical with that of {{{{{ Cd}_{ 1-x} {Mn }_{x }Te }}}}. Neutron inelastic scattering measure-ment has been performed for {{{{{ Zn}_{ 0.6} { Mn}_{ 0.4}Te }}}} sample using the cold neutron spectrometer. AGNES. High resolution measurement with the energy resolution of {{{{ TRIANGLE E= +- .01meV}}}} was carried out in the temperature range from 10K to the ambient. Critical scattering, closely related with the spin glass transition, has been observed for the first time in this semimagnetic semi-conductor. The critical scattering is observed at temperatures in the vicinity of the spin glass transition temperature, 17K. The scattering is observed as a kind of quasielastic scattering in the reciprocal range where the elastic magnetic diffuse scattering has been observed, e.g., 11/20 reciprocal point, indicating the spin fluctuation has dynamic components in this material. Photoconductivity has been discovered below 150K in {{{{{ Zn}_{ 0.4} {Mn }_{0.6 } Te}}}}. The electric AC conductivity has been increased dramatically under the laser light with the wave lengths of {{{{ lambda =6328,5145 and4880 }}}}$\AA$ ,respectively. After the light was darkened, the conductivity was reduced to the original level after about 2000 seconds at 50K, being above the spin glass transition temperature. This phenomenon is the typical persistent photoconductivity; PPC which was similarly found in {{{{ { Zn}_{ 1-x} { Mn}_{x} Te}}}}.

• 한국안광학회지
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• 제1권2호
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• pp.49-55
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• 1996

본 연구에서는 LFPCVD법으로 수소화왼 비정질 탄소(a-C:H) 박막을 제작하였으며, 수소화된 비정질 규소 (a-Si:H)에서 주로 나타나는 지속광전기전도도(PPC) 현상을 a-C:H에서 처음으로 관찰하였다. 관찰된 PPC의 크기는 실온에서 암전기전도도의 3배 이상이며, 수 시간 이상 지속되었다. PPC의 크기는 조광시간이 증가함에 따라서 증가를 하며, 조광온도가 증가함에 따라서는 감소를 하여 $120^{\circ}C$ 이상에서 완전히 사라졌다. 또한 PPC의 붕괴는 확장지수붕괴(Stretched Exponential Decay) 함수로 설명할 수 있었다. 이로 미루어 볼 때 a-C:H에서의 PPC는 시료의 이질성과 밀접한 관련이 있다고 생각된다.

• 한국결정성장학회지
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• 제5권1호
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• pp.78-86
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• 1995

유리기판 위에 electron beam으로 증착(EBE)된 CdTe film의 결정구조 및 전기 전도도와 광 전도도를 조사하였다. 그 구조는 거의 hexagonal phase 이었으며 Cubic phas가 약간 포함된 다결정이었다. 암 전기 전도도(dark electric conductivity)는 $1-^{-8} {\Omega}^{-1} cm^{-1}$정도이고 $300^{\circ}C$에서 1시간 동안 열처리하여 약간 증가되었다. 온도가 증가됨에 따른 전기 전도도로부터 계산된 활성화 에너지는 실온에서 증착된 film의 경우1.446 eV이었다. 흡수계수로부터 구한 광학적 band gap은 직접 천이(direct transition)인 경우 1.52 eV이었고 간접 천이(indirect transition)인 경우 1.44eV이었다. Film의 광전도도는 약$1-^{-8} {\Omega}^{-1} cm^{-1}$정도이고, 실온에서 대략 600 nm일때 가장 크다. 광전기 전도도는 850 nm에서 증가하기 시작하며 이는 CdTe 다결정의 활성화 에너지 (activation energy)인 1.446 eV와 근사하다.

• 전기의세계
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• 제17권2호
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• pp.16-26
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• 1968

Cds is possible to add excess donors and to compensate partially using other group metals as acceptors. The impurities can ble incorporated either during crysta growth or by diffusion into a bulkcrystal. The addition of rimpurities leads also to the production of vacancies in a manner depending on the atmosphere surrounding the crystal during growth, during the diffusion process or using bulk. Cds of the mentioned above affects spectral sensitivity, speed of response, the variation on photocurrent, electron life time, and decay of photoconductivity with temperature and with intensity of illumination. In the work to be deseribed, these properties have been studied between liquid nitrogen and room temperature. In addition, the electron trap distribution has been correlated with speed of response, variation of photocurrent with temperature in various atmosphere. Four major trapping levels have been observed, and their identification with impurity and vacancy levels is discussed. And also the effects of lattice imperfections on the photoconductive properties CdS were investigated in detail.

• 전기학회논문지P
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• 제51권3호
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• pp.142-148
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• 2002

Considerable progress has been made in organic photorefractive materials, since the first observation of photorefractive phenomena from organic materials. Within recent years, a large number of organic photorefractive materials, especially amorphous materials, have been developed based on polymeric composites, fully functional polymers and the multi-functional chromophore approach. Among these organic photorefractive materials, some of them containing carbazole components as a charge transporting function have been demonstrated to exhibit high performance photorefractive effects. The carbazole building blocks with charge transporting function or multifunctions play a very important role in photorefraction. In this paper, it confirmed that acceptor-substituted carbazoles show the multifunctionality both of photoconductivity and electro-optic(EO) activity and photorefractive materials newly can be developed with acceptor-substituted carbazoles.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1988년도 춘계학술대회 논문집
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• pp.13-16
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• 1988

In this paper, image storage and display of scattering mode using 7/65/35 PLZT ceramics was studied. Scattering in a ferroelectric poly-crystal depends on its grain size and domain orientations. 7/65/35 PLZT ceramics is ferroelectric and transparent. Image can be stored in the ceramic substrate by poling it selectively through a pair of electrodes with the pattern or a set of a photoconductivity film and two transparent electrodes.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1055-1055
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• 2009

The mobility of charge carriers has been investigated in the pristine and phosphorescent materials doped host materials using time-of-flight photoconductivity technique. The field and temperature dependences of the mobility were analyzed with the Gaussian disorder model. Based on these results, we optimized white organic light emitting diodes (WOLEDs) consisting of multi-emitting layers doped with phosphorescent and fluorescent dopants. Especially, we studied the effect of each emitter position and an interlayer on the device characteristics of WOLEDs.