• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.505-508
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• 1987

The structure of vacuum evaporated PbO films is investigated. Also, the Photosensitivity and dark resistivity are measured. The dominant structure and orientation of these films were red (tetragonal) form, and <110> and <101> direction under- the suitable deposition conditions. And the crystallite size of them was about $2um{\times}0.2um$. These PbO films have good photosensitivity(r=0.9) and high dark resistivity. (${\rho}=10^{14}{\Omega}{\cdot}cm$)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.492-496
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• 2001

Due to their better photosensitivity in X-ray, the amorphous selenium based photoreceptor is widely used on the X-ray conversion materials. It was possible to control the charge carrier transport of amorphous selenium by suitably alloying a-Se with other elements(e,g. As, Cl). In this paper, We investigated dopants(As, Cl) composition rate to improve dark resistivity and transport properties of charge carrier in amorphous selenium using by direct X-ray conversion material. Alloying a-Se with As inhibits the recrystallization of a-Se but introduces undesirable deep hole traps. then doping with Cl(in the ppm range) compensates for the deep hole traps. We investigated their composition rate in various doping conditions and then obtained optimum dopant composition rate. The result was Se-As 0.3%-Cl 30 ppm and X-ray Sensitivity was 0.57 pc/pixel$.$mR at 137 $\mu\textrm{m}$ x 137 $\mu\textrm{m}$ Pixel area.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.505-508
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• 2001

Currently there is much interested in removing latent charge that is caused to latent image effect and blurring of obtained image as well as reduction of x-ray conversion efficiency in digital radiography system. To remove latent charge a-Se film is irradiated by light with 3500 lux using halogen lamp and optical fiber. We measured dark current and photosensitivity to analyze removing effect of latent charge, then compared with and without light erasing method. The reduction of measured signal due to latent charge effect was 32.3%, and the removal effect of latent charge by using light erase method was its 95.5%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.497-500
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• 2001

Due to their better photosensitivity in X-ray, the amorphous selenium based photoreceptor is widely used on the X-ray conversion materials. It was possible to control the charge carrier transport of amorphous selenium by suitably alloying a-Se with other elements(e,g. As, Cl). The charge transport properties of amorphous Selenium is decided on hole which is induced from metal to selenium in metal-selenium junction and which is transferred in a-Se bulk. This phenomenon is resulted of changing electric field owing to increasing of space charge by deep trap of a-Se bulk. In this paper, We dopped the chlorine to compensate deep hole trap and deposited blocking layer using dielectric material to prevent from increasing space charge for injection charge between metal electrode and a-Se layer. We compared space charge and the decreasing of trap density through measuring dark and photo current.

• Proceedings of the Materials Research Society of Korea Conference
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• 2004.05a
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• pp.66-66
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• 2004

• Journal of the Korean Ceramic Society
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• v.39 no.12
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• pp.1158-1163
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• 2002

An Ge/B-doped optical fiber with high photosensitivity was fabricated to induce large second-order optical nonlinearity by UV poling. It was found that long period fiber gratings were inscribed on the fiber by the 248 nm KrF excimer laser irradiation with pulse energy of 116 mJ/$cm^2$ and pulse frequency of 10 Hz without hydrogen loading treatment. The photosensitivity was measured by use of the long period fiber grating pair method and the refractive index change of 3.3$10{\times}^{-3}$ was found to be induced in the core of the optical fiber by the KrF excimer laser irradiation of 8.67 kJ/$cm^2$. An H-shaped optical fiber was also fabricated for the UV poling through optimization of the fiber drawing condition.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.2
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• pp.201-207
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• 2012

Pulsed lasers at the 613 nm and 1064 nm wavelengths on nanoseconds have been utilized to characterize the damage on Si photodiode exposed to intense illumination. Morphological damages and structural changes at sites on the photodiode irradiated during microseconds of laser pulses were analyzed by FE-SEM images and XRD patterns, respectively. The removal of oxide coating, ripple, melting marks, ridges, and crater on photodiodes were definitely observed in order of increasing the pulse intensities generated above the damage threshold. Then, the degradation in photosensitivity of the Si photodiode irradiated by high power density pulses was measured as a function of laser irradiation time at the various wavelengths. The free charge carrier and thermal diffusion mechanisms could have been invoked to characterize the damage. The relative photosensitivity data calculated using the thermal diffusion model proposed in this paper have been compared with the experimental data irradiated above the damage threshold.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.144.2-144
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• 2003

• Journal of the Korean Graphic Arts Communication Society
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• v.11 no.1
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• pp.71-84
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• 1993

Practically to put use high-photosensitive polymer, poly(vinyl cinnamoyl acetate), we investigated and confirmed UCHIDA`s synthesis, according to control solvent, which is the esterification of poly (vinyl alcohol) with monochloroacetic acid and can be freely conrolled the successive cinnamoyl acetoxyl esterfication of PVCiA, and intruducing photosensitizers,studied the photosensitivity of PVCiA.

• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.660-663
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• 2005

Aiming the development of novel acid amplifiers, 2-hydroxyphenyl-4-methylbenzenesulfonate (1), 3-hydroxyphenyl-4-methylbenzene sulfonate (2), 4-hydroxyphenyl-4-methylbenzenesulfonate (3) were synthesized as the aromatic acid amplifiers with good thermal stability. They were autocatalytically generated p-toluenesulfonic acid in the presence of small amount of acid evolved from a photoacid generator. These aromatic sulfonates showed excellent thermal stability in PtBMA film and were proven to be the first aromatic acid amplifier to act as a photosensitivity enhancer. When these compounds were coupled with a chemically amplified photoresist system, photosensitivity was enhanced up to 3~6 folds.