• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05b
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• pp.51-54
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• 2002

Recently, due to its better photosensitivity in X-ray, the amorphous selenium based photoreceptor is used on digital direct method conversion material. Compared to other photoconductive material, amorphous selenium has good X-ray response characteristic and low leakage current. It has many parameters of detecting X-ray response on selenium. Among of them, it is well known that manufacture of a-Se is the most basic element. In this paper, we fabricated two types of amorphous selenium sample which had time variable. The one was fabricated continuous deposition sample and the other was step by step sample. Thickness of sample was $300{\mu}m$ and top electrode was evaporated gold. We investigated the leakage current and photo current of them and analysed their electrical characteristics. For analyzing morphology of samples, SEM and surface was pictured. We found that step by step deposition method could be applied for novel fabricating amorphous selenium film.

• Rapid Communication in Photoscience
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• v.3 no.2
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• pp.38-41
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• 2014

The title compound (BMBZA) was designed and synthesized as a novel fluorescent amorphous molecular material. BMBZA was found to exhibit solvatofluorochromism and to readily form an amorphous glass by cooling the melt on standing. In addition, the morphological change from crystalline state to amorphous one could be induced by mechanical grinding. Although fluorescence was scarcely observed for the crystalline sample of BMBZA, the grinding the sample was found to enhance the fluorescence emission, that is, BMBZA exhibited on-off type mechanofluorochromism.

• The Korean Journal of Ceramics
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• v.1 no.2
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• pp.75-80
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• 1995

Development of phases, evolution of microstructures, and dielectric response characteristics of amorphous lead iron tungstates during crystabllization were investiageted. A series of mircographs showing the evolution sequence of microstructures is presented. Crystallization was observed to initiate from inside of the amorphous material. A cubic perovskite phase developed fully at $760^{\circ}C$ from amorphous state via intermediate metastable crystalline structures. Dielectric constant of amorphous PFM was totally insensitive to the temperature change around the Curie temperature of crystalline material. Sintered pellet, with relative density of 96% and an almost pore-free dense internal microstructure, could be prepared from amorphous powder.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.296-300
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• 2002

Thin films of Hydrogenated amorphous carbon(a-C:H) are generally exhibited by high electrical resistivities from 10$^2$ to 10$\^$16/ Ω$.$cm, resulting in an interesting material for high power, high temperature MIS devices applications. The hydrogenated amorphous carbon(a-C:H) films were deposited on silicon and glass using an rf plasma enhanced CVD method. The resultant film properties were evaluated in the respect of material based on r.f. power variation. The hydrogenated amorphous carbon(a-C:H) films of thickness ranging from 30 to 50 m were deposited at the pressure of 1 ton with the mixture of methane and hydrogen. We have used rf-IR( courier transform IR) and AFM(Atomic force microscopy) for determining physical properties and current-voltage(I-V) measurement for electrical Properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.73-76
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• 1999

In this thesis, we fabricate a zero-magnetostrictive amorphous ribbon measure the impeadance effect, and then Investigate possibility as a sensor material. $Co_{72.5}$F $e_{0.5}$M $o_{2}$ $B_{15}$ S $i_{5}$ is used as composition of specimen alloy. We first melt the specimen in high frequency induction furnace and then rapidly quench it by using single roll technique. As the result, we obtain a ribbon where thickness is 12${\mu}{\textrm}{m}$, width is 1mm and length is 93mm. Consequently, it is proved through this study that zero-magnetostrictive amorphous ribbon can be used as an excellent magnetic sensor material.rial.l.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.399-402
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• 2002

This paper is researched that electric characteristic of Digital x-ray radiography technique with changing composition ratio of Iodine. Dopant material, Iodine is evaporated with amorphous selenium. Thorugh the old papers say, doponted Iodine will be down the created trap level because of Arsenic dopant material in amorphous selenium. Arsenic material of Composition ratio in amorphous selenium is fixed with 0.3% and test sample is deposited composition of 30, 100, 300, 500, 700ppm with thermal evaporate system. Experimental measurement is performed by dark current and x-ray sensitivity in amorphous selenium based radition detector sensor. Fabricated test sample thickness is $30{\mu}m$ and injected voltage is $3{\mu}m$，$6{\mu}m$，$9{\mu}m$ to both electrode. Experimental results showed that the net charge of composition rate of 30ppm is 398.88 pc/mR/$cm^2$ very high. And increase of the Iodine composition ratio is tendency to the decrease of net charge. Doping changing composition of Iodine in amorphous selenium detector offered to basical information of amorphous selenium material.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.12 no.1
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• pp.18-26
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• 1999

In this study, the undoped amorphous layers and phosphorus doped amorphous layers are fabricated using LPCVD at 531$^{\circ}C$ with SiH$_4$ gas or at same temperature with PH$_3$ gas during deposition, respectively. The thickness of deposited amorphous layer from this experiments was 5000 ${\AA}$. In this experiments, undoped amorphous layers are deposited with SiH$_4$and Si$_2$H$\_$6/ gas in a low pressure reactor using LPCVD. These amorphous layers can be doped for poly-silicon by phosphorus ion implantation. The experiments of this study are carried out by phosphorus ion implantation with energy 40 keV into P doped and undoped amorphous silicon layers. The distribution of phosphorus profiles are measured by SIMS(Cameca 6f). Recoiling effects and two dimensional profiles are also explained by comparisions of experimental and simulated data. Finally range moments of SIMS profiles are calculated and compared with simulation results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.268-271
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• 2004

The phase transition from amorphous to crystalline states, and vice versa, of $Ge_2Sb_2Te_5$ films by applying electrical pulses have been studied. This material can be used as nonvolatile memory. The reversible phase transition between the amorphous and crystalline states, which is accompanied by a considerable change in electrical resistivity, is exploited as means to store bits of information. The nonvolatile memory cells are composed of a simple sandwich (metal/chalcogenide/metal). It was formed that the threshold voltage depends on thickness, electrode distance, annealing time and temperature, respectively.

• Transactions on Electrical and Electronic Materials
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• v.2 no.3
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• pp.1-6
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• 2001

A simulation method is proposed to study the amorphous structure of carbon nitride. The material properties of a non-uniform nitrogen distribution in an amorphous CN matrix can be studied. The cohesive energy of a group of randomly generated atoms can be minimized to find the relative positions of atoms. From the calculated configuration of atoms, many properties of amorphous carbon nitride can be calculated such as bulk modulus, P-V curve, sp$^3$/sp$^2$ ratio of carbon, and vibrational spectra. The calculation shows that the cohesive energy of non-uniform nitrogen distribution is lower than that of a uniform distribution. This may suggest that the regular structure of carbon nitride can at most be metastable. It is not easy to incorporate nitrogen atoms into a carbon matrix.

• 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.