• 통합자연과학논문집
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• 제5권4호
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• pp.211-215
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• 2012

Single-crystalline silicon nanowire arrays (SiNWAs) using electroless metal-assisted etchings of p-type silicon were successfully fabricated. Ag nanoparticle deposition on silicon wafers in HF solution acted as a localized micro-electrochemical redox reaction process in which both anodic and cathodic process took place simultaneously at the silicon surface to give SiNWAs. The growth effect of SiNWs was investigated by changing of etching times. The morphologies of SiNWAs were obtained by SEM observation. Well-aligned nanowire arrays perpendicular to the surface of the silicon substrate were produced. Optical characteristics of SiNWs were measured by FT-IR spectroscopy and indicated that the surface of SiNWs are terminated with hydrogen. The thicknesses and lengths of SiNWs are typically 150-250 nm and 2 to 5 microns, respectively.

• 한국표면공학회지
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• 제32권3호
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• pp.235-238
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• 1999

Silicon dioxide films were prepared by anodizing silicon wafers in an ethylene $glycol+HNO_3(0.04{\;}N)$ at 20 to $70^{\circ}C$. The voltage between silicon anode and platinum cathode was measured during this process. Under the constant current electrolysis, the voltage increased with oxide film growth. The transition time at which the voltage reached the predetermined value depended on the temperature of the electrolyte. After the time of electrolysis reached the transition time, the anodization was changed the constant voltage mode. The depth profile of oxide film/Si substrate was confirmed by XPS analysis to study the influence of the electrolyte temperature on the anodization. Usually, the oxide-silicon peaks disappear in the silicon substrate, however, this peak was not small at $45^{\circ}C$ in this region.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.116-117
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• 2006

We investigated selective emitter effect of Porous Silicon (PSI) as antireflection coatings (ARC). The thin PSi layer, less than 100nm, was electrochemically formed by electrochemical method in about $3{\mu}m$ thick $n^+$ emitter on single crystalline silicon wafer (sc-Si). The appropriate PSi formations for selective emitter effect were carried out a two steps. A first set of samples allowed to be etched after metal-contact processing and a second one to evaporate Ag front-side metallization on PSi layer, by evaluating the I-V features The PSi has reflectance less than 20% in wavelength for 450-1000nm and porosity is about 60%. The cell made after front-contact has improved cell efficiency of about in comparison with the one made after PSi. The observed increase of efficiency for samples with PSi coating could be explained not only by the reduction of the reflection loss and surface recombination but also by the increased short-circuit current (Isc) within selective emitter. The assumption was confirmed by numerical modeling. The obtained results point out that it would be possible to prepare a solar cell over 15% efficiency by the proposed simple technology.

• 한국세라믹학회지
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• 제40권8호
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• pp.770-776
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• 2003

(111) 및 (100) 단결정 실리콘 웨이퍼에 대하여 #140 mesh와 #600 mesh의 연삭숫돌을 사용하여 연삭가공을 행하고 가공에 의한 표면품위의 변화를 관찰하였다. 이를 위하여 Atomic Force Microscope(Am)을 사용하여 미세거칠기를 분석하고 라만 분광법(Raman spectroscopy)을 통하여 결정구조, 상변화 및 잔류응력을 분석하였다. 그 결과 연삭가공 후에 (111) 면에서 미세거칠기가 더 크게 나타났으며 실리콘이 다이아몬드구조의 Si-I에서 Si-III(body centered tetragonal) 및 Si-XII(rhombohedral)로 전이하는 현상을 라만스펙트럼 분석을 통해 확인하였다. 또한 연삭가공에 의하여 패인 구덩이에서는 일반적인 가공표면과 다른 라만스펙트럼이 관찰되어, 표면에 인가된 잔류응력이 새로운 표면생성으로 해소되었음을 알수 있었다. 또한 열처리에 의한 재료의 표면품위개선효과를 분석하기 위하여 대기 중에서 열처리를 시행한 결과 열처리는 잔류응력의 해소와 상전이의 회복에 효과적인 것으로 나타났다.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권4호
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• pp.181-184
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• 2004

Thin films of single phase, polycrystalline silicon germanium (Si$_{1-x}$ Ge$_{x}$) were prepared by ion-beam evaporation (IBE) using Si-Ge multi-phase targets. After irradiation of the targets by a pulsed light ion beam with peak energy of 1 MV, 450 and 480 nm thick films were deposited on Si single crystal and quartz glass substrates, respectively. From XRD analysis, the thin films consisted of a single phase Si$_{1-x}$ Ge$_{x}$, whose composition is close to those of the targets.rgets.

• Current Photovoltaic Research
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• 제5권2호
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• pp.63-67
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• 2017

Aluminum oxide ($Al_2O_3$) film deposited by atomic layer deposition (ALD) is known to supply excellent surface passivation properties on crystalline Si surface. The quality of passivation layer is important for high-efficiency silicon solar cell. double-layer structures have many advantages over single-layer materials. $Al_2O_3/SiN_X$ passivation stacks have been widely adopted for high- efficiency silicon solar cells. The first layer, $Al_2O_3$, passivates the surface, while $SiN_X$ acts as a hydrogen source that saturates silicon dangling bonds during annealing treatment. We explored the properties on passivation film of $Al_2O_3/SiN_X$ stack layer with changing the conditions. For the post annealing temperature, it was found that $500^{\circ}C$ is the most suitable temperature to improvement surface passivation.

• 한국전기전자재료학회논문지
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• 제13권2호
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• pp.125-130
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• 2000

Two step growth of reduced pressure chemical vapor eposition has been successfully developed to achieve in-situ phosphorus-doped silicon epilayers, and the characteristic evolution on their microstructures has been investigated using scanning electron microscopy, transmission electron microscopy, and secondary ion mass spectroscopy. The two step growth, which employs heavily in-situ P doped silicon buffer layer grown at low temperature, proposes crucial advantages in manipulating crystal structures of in-situ phosphorus doped silicon. In particular, our experimental results showed that with annealing of the heavily P doped silicon buffer layers, high-quality epitaxial silicon layers grew on it. the heavily doped phosphorus in buffer layers introduces into native oxide and plays an important role in promoting the dispersion of native oxides. Furthermore, the phosphorus doping concentration remains uniform depth distribution in high quality single crystalline Si films obtained by the two step growth.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.105.1-105.1
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• 2011

To enhance the performance of photovoltaic a-Si:H solar cells with a hybrid-type light absorbing structure of single crystal silicon nanoparticles (Si NPs) in a-Si:H matrix, single crystal Si NPs were produced by laser pyrolysis. The Si NPs were synthesized by $SiH_4$ gas decomposition using a $CO_2$ laser. The properties of Si NPs were controlled by process parameters such as $CO_2$ laser power, reactive gas pressure, and $H_2/SiH_4$ gas flows. The crystalline properties and sizes of Si NPs were analyzed by High Resolution Transmission Electron Microscopy (HRTEM). The sizes of Si NPs were controllable in the range of 5-15 nm in diameter and the effects of process parameters of laser pyrolysis were systematically investigated.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.243-247
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• 2012

The paper focuses on an anti-reflection (AR) coating deposited by PECVD in silicon solar cell fabrication. AR coating is effective to reduce the reflection of the light on the silicon wafer surface and then increase substantially the solar cell conversion efficiency. In this work, we carried out experiments to optimize double AR coating layer with silicon nitride and silicon oxide for the silicon solar cells. The p-type mono crystalline silicon wafers with $156{\times}156mm^2$ area, 0.5-3 ${\Omega}{\cdot}cm$ resistivity, and $200{\mu}m$ thickness were used. All wafers were textured in KOH solution, doped with $POCl_3$ and removed PSG before ARC process. The optimized thickness of each ARC layer was calculated by theoretical equation. For the double layer of AR coating, silicon nitride layer was deposited first using $SiH_4$ and $NH_3$, and then silicon oxide using $SiH_4$ and $N_2O$. As a result, reflectance of $SiO_2/SiN_x$ layer was lower than single $SiN_x$ and then it resulted in increase of short-circuit current and conversion efficiency. It indicates that the double AR coating layer is necessary to obtain the high efficiency solar cell with PECVD already used in commercial line.

• 센서학회지
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• 제22권3호
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• pp.175-180
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• 2013

This paper describes the characteristics of cubic silicon carbide (3C-SiC) films grown on a carbonized Si(100) substrate, using hexamethyldisilane (HMDS, $Si_2(CH_3)_6$) as a safe organosilane single precursor in a nonflammable $H_2$/Ar ($H_2$ in Ar) mixture carrier gas by atmospheric pressure chemical vapor deposition (APCVD) at $1280^{\circ}C$. The growth process was performed under various conditions to determine the optimized growth and carbonization condition. Under the optimized condition, grown film has a single crystalline 3C-SiC with well crystallinity, small voids, low residual stress, low carrier concentration, and low RMS. Therefore, the 3C-SiC film on the carbonized Si (100) substrate is suitable to power device and MEMS fields.