• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.8
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• pp.950-958
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• 1988

We have implemented a RTA system using W-halogen lamps and tried to recrystallize the phosphorus ion implanted amorphous silicon on insultor (SOI) taking advantages of seeding window. The purpose of this study is to investigate the possibility of a typical crystalline orientation occurred during the solidifying process of molten amorphous silicon layer. Experimental results show that several twin boundaries are found on the seeding window region after annealing for 15 sec at 1040\ulcorner. These twin boundaries represent that the recrystallization is partialy possible and when the annealing is done at 1150\ulcorner, (100) etch pits with <110> facets are found on the solidified amorphous silicon layer. Consequently, Hall mobility of recrystallized silicon film is measured and the thermal behavior of grain boundary is also observed by SEM.

• Korean Journal of Materials Research
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• v.4 no.6
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• pp.644-650
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• 1994

The submicron powders of high-purity silicon have been produced by Electrohydrodynamic Atomization. Field-emission scanning transmission electron microscopy(STEM) is used to determine the microstructure and solidification phase. .Then it is found that the droplets less than 60nm diameter are solidified as the amorphous phase. A useful and accessible characterization of atomic arrangements in amorphous solids can be given in terms of a radial distribution function. According to experimental determinations of the radial distribution function for amorphous silicon, its similarity to the crystalline structure at small radial distances indicates that the basic tetrahedral arrangement found in the diamond cubic structure of silicon must be maintained in the amorphous structure.

• Proceedings of the Materials Research Society of Korea Conference
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• 2006.05a
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• pp.16.1-16.1
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• 2006

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.05a
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• pp.42-45
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• 1992

The poly silicon thin films were prepared by solid phase crystallization at 600$^{\circ}C$ of amorphous silicon films deposited on Corning 7059 glass and (100) silicon wafer with thermally grown SiO$_2$substrate by plasma enhanced chemical vapor deposition with varying rf power, deposition temperature, total flow rate. Crystallization time, microstructure, absorption coefficients were investigated by RAMAN, XRD analysis and UV transmittance measurement. Crystallization time of amorphous silicon films was increased with increasing rf power, decreasing deposition temperature and decreasing total flow rate.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.3
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• pp.130-136
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• 1989

Electrical transport and thermally induced metastability in hydrogenated amorphous silicon (a-Si:H) thin film transistors (TFTs) using boron-doped amorphous silicon as an active layer have been studied. The device characteristics n-channel and p-channel operations. The thermal quenching experiments on amorphous silicon-silicon nitride ambipolar TFT give clear evidence for the co-existence of two distinct metastable changes. The densities of metastable active dopants and dangling bonds increase with the quenching temperature. On the other hand, the interface state density appears to decrease with increasing quenching temperature.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.7
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• pp.85-94
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• 1994

A high-resolution transmission electron microscopy study of the solid phase crystallization of the amorphous silicon thin films, deposited on SiOS12T at 52$0^{\circ}C$ by low pressure chemical vapor deposition and annealed at 55$0^{\circ}C$ in a dry N$_{2}$ ambient was carried out so that the arrangement of atoms in the crystalline silicon and at the amorphous/crystalline interface of the growing grains could be understood on an atomic level. Results show that circular crystalline silicon nuclei have formed and then the grains grow to an elliptical or dendritic shape. In the interior of all the grains many twins whose{111} coherent boundaries are parallel to the long axes of the grains are observed. From this result, it is concluded that the twins enhance the preferential grain growth in the <112> direction along {111} twin planes. In addition to the twins. many defect such as intrinsic stacking faults, extrinsic stacking faults, and Shockley partial dislocations, which can be formed by the errors in the stacking sequence or by the dissociation of the perfect dislocation are found in the silicon grain. But neither frank partial dislocations which can be formed by the condensation of excess silicon atoms or vacancies and can form stacking fault nor perfect dislocations which can be formed by the plastic deformation are observed. So it is concluded that most defects in the silicon grain are formed by the errors in the stacking sequence during the crystallization process of the amorphous silicon thin films.

• The Korean Journal of Ceramics
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• v.4 no.3
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• pp.245-248
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• 1998

Porous carbon fiber composites (CFCs) having variable specific surface area ranging 35~1150 $\m^2$/g were reacted to produce silicon carbide fiber composites with SiO vapor generated from a mixture of Si and $SiO_2$ at 1673 K for 2 h under vacuum. Part of SiO vapor generated during conversion process condensed on to the converted fiber surface as amorphous silica. Chemical analysis of the converted CFCs resulting from reaction showed that the products contained 27~90% silicon carbide, 7~18% amorphous silica and 3~63% unreacted carbon, and the composition depended on the specific carbide, 7~18% amorphous silica and 3~63% unreacted carbon, and the composition depended on the specific surface area of CFCs. CFC of higher specific surface area yielded higher degree of conversion of carbon to silicon and conversion products of lower mechanical strength due to occurrence of cracks in the converted caron fiber. As the conversion of carbon to silicon carbide proceeded, pore size of converted CFCs increased as a result of growth of silicon carbide crystallites, which is also linked to the crack formation in the converted fiber.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.80-82
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• 2009

The dependence of the efficiency characteristics of hydrogenated amorphous silicon single junction solar cells on the various intrinsic layer thickness has been investigate in the glass/$SnO_2$:F/p,i,n a-Si:H/Al type of amorphous silicon solar cells by cluster PECVD system. The open circuit voltage, short circuit current, fill factor and conversion efficiency have been measured under AM 1.5 condition. The result of the cell performance was improved about 8.2% due to an increase in the short circuit current.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.4
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• pp.255-260
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• 1998

Behavior of solid phase crystallizations (SPC) of RF sputtered and LPCVD amorphous hydrogenated silicon film were investigated. LPCVD films showed the higher degree of crystallinity and larger grain size than sputtered films. The applicable degree of crystallinity was also obtained from sputtered films. The deposition method of amorphous silicon film influenced the behavior of post annealing SPC. Observed degree of crystallinity of sputtered films strongly depended on the partial pressure of hydrogen in deposition. The higher deposition temperature of sputtering provided the better crystallinity after SPC. Due to the high degree of poly-crystallinity, the retardation of larger grain growth was observed on sputtering film.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.2
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• pp.354-356
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• 2017

We focused on light management technology in amorphous silicon solar cells to suppress increase in absorber thickness for improving power conversion efficiency (PCE). $MgF_2$ and $TiO_2$ anti-reflection layers were coated on both sides of Asahi VU ($glass/SnO_2:F$) substrates, which contributed to increase in PCE from 9.16% to 9.81% at absorber thickness of only 150 nm. Also, we applied very thin $MgF_2$ as a rear reflector at n-type nanocrystalline silicon oxide/Ag interface to boost photocurrent. By reinforcing rear reflection, we could find the PCE increase from 10.08% up to 10.34% based on thin absorber about 200 nm.