• Proceedings of the Korean Vacuum Society Conference
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• 2005.08a
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• pp.92-92
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• 2005

• Korean Journal of Metals and Materials
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• v.50 no.4
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• pp.331-337
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• 2012

Electrical properties as a function of composition in silicon nitride ($SiN_x$) films grown at low temperatures ($<200^{\circ}C$) were studied for applications to photonic devices and thin film transistors. Both silicon-rich and nitrogen-rich compositions were successfully produced in final films by controlling the source gas mixing ratio, $R=[(N_2\;or\;NH_3)/SiH_4]$, and the RF plasma power. Depending on the film composition, the dielectric and optical properties of $SiN_x$ films varied substantially. Both the resistivity and breakdown field strength showed the maximum value at the stoichiometric composition (N/Si = 1.33), and degraded as the composition deviated to either side. The electrical properties degraded more rapidly when the composition shifted toward the silicon-rich side than toward the nitrogen-rich side. The composition shift from the silicon-rich side to the nitrogen-rich side accompanied the shift in the photoluminescence characteristic peak to a shorter wavelength, indicating an increase in the band gap. As long as the film composition is close to the stoichiometry, the breakdown field strength and the bulk resistivity showed adequate values for use as a gate dielectric layer down to $150^{\circ}C$ of the process temperature.

• Proceedings of the Korea Crystallographic Association Conference
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• 2007.11a
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• pp.7-7
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• 2007

• Proceedings of the Korean Vacuum Society Conference
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• 2007.02a
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• pp.132-132
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• 2007

• Current Photovoltaic Research
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• v.11 no.4
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• pp.114-117
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• 2023

Transparent Photovoltaic (PV) modules have recently been in the spotlight because they can be applied to buildings and vehicles. However, crystalline silicon (c-Si) solar modules, which account for about 90% of the PV module market, have the disadvantage of applying transparent PV modules due to their unique opacity. Recently, a see-through type PV module using a crystalline silicon solar strap has been developed. However, there is a problem due to a decrease in aesthetics due to the metal ribbon in the center of the see-through type PV module and difficulty bonding the metal ribbon due to the low voltage output of the strap. In this study, to solve this problem, we developed a fabrication process of series connected c-Si solar strap cells using the c-Si solar cells. We succeeded in fabricating a series connected strap with a width of 2-10 mm, and we plan to manufacture an aesthetic see-through type c-Si PV module.

• Current Photovoltaic Research
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• v.8 no.4
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• pp.120-123
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• 2020

Transparent photovoltaics (PV) are used in various applications such as building-integrated photovoltaics (BIPV). However, crystalline silicon (c-Si) is not used for developing transparent PV due to its opaque nature. Here. we fabficate the three holes in 6-inch c-Si solar cells using laser scribing process with an opening area ratio of about 6.8% for transparent c-Si solar modules. Moreover, we make the shingled strings using the perforated cells. Our 7 interconnected shingled string PV cells with 21 holes show a solar to power conversion of 5.721 W. In next work, we will fabricate a transparent c-Si PV module with perforated strings.

• Proceedings of the Korean Magnestics Society Conference
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• 2004.12a
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• pp.31-32
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• 2004

• Proceedings of the Korean Vacuum Society Conference
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• 2004.08a
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• pp.169-169
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• 2004

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.236.1-236.1
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• 2015

The surface morphology of front transparent conductive oxide (TCO) films is very important to achieve high current density in amorphous silicon (a-Si) thin film solar cells since it can scatter the light in a better way. In this study, we present the low cost hydrothermal deposited uniform zinc oxide (ZnO) nano-flower structure with various aspect ratios for a-Si thin film solar cells. The ZnO nano-flower structures with various aspect ratios were grown on the RF magnetron sputtered AZO films. The diameters and length of the ZnO nano-flowers was controlled by varying the annealing time. The length of ZnO nano-flowers were varied from 400 nm to $2{\mu}m$ while diameter was kept higher than 200 nm to obtain different aspect ratios. The ZnO nano-flowers with higher surface area as compared to conventional ZnO nano structure are preferred for the better light scattering. The conductivity and crystallinity of ZnO nano-flowers can be enhanced by annealing in hydrogen atmosphere at 350 oC. The vertical aligned ZnO nano-flowers showed higher haze ratio as compared to the commercially available FTO films. We also observed that the scattering in the longer wavelength region was favored for the high aspect ratio of ZnO nano-flowers. Therefore, we proposed low cost and vertically aligned ZnO nano-flowers for the high performance of thin film solar cells.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.341-341
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• 2016

The discovery of light emission in nanostructured silicon has opened up new avenues of research in nano-silicon based devices. One such pathway is the application of silicon quantum dots in advanced photovoltaic and light emitting devices. Recently, there is increasing interest on the silicon quantum dots (c-Si QDs) films embedded in amorphous hydrogenated silicon-nitride dielectric matrix (a-SiNx: H), which are familiar as c-Si/a-SiNx:H QDs thin films. However, due to the limitation of the requirement of a very high deposition temperature along with post annealing and a low growth rate, extensive research are being undertaken to elevate these issues, for the point of view of applications, using plasma assisted deposition methods by using different plasma concepts. This work addresses about rapid growth and single step development of c-Si/a-SiNx:H QDs thin films deposited by RF (13.56 MHz) and ultra-high frequency (UHF ~ 320 MHz) low-pressure plasma processing of a mixture of silane (SiH4) and ammonia (NH3) gases diluted in hydrogen (H2) at a low growth temperature ($230^{\circ}C$). In the films the c-Si QDs of varying size, with an overall crystallinity of 60-80 %, are embedded in an a-SiNx: H matrix. The important result includes the formation of the tunable QD size of ~ 5-20 nm, having a thermodynamically favorable <220> crystallographic orientation, along with distinct signatures of the growth of ${\alpha}$-Si3N4 and ${\beta}$-Si3N4 components. Also, the roles of different plasma characteristics on the film properties are investigated using various plasma diagnostics and film analysis tools.