• Electrical & Electronic Materials
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• v.7 no.3
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• pp.206-212
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• 1994

In this paper, We discuss the $POCI_3$ doping process according to the variation of deposition temperature, gas flow rate and doping time. The factors acted with $POCI_3$ doping are gas flow rate deposition temperature and time etc. Among them the temperature is the most important factor. For the $POCI_3$ flow rate, it should not exceed the resistivity saturation point developed on poly surface by annealing treatment. Therefore, this study suggests the optimum conditions of Poly-silicon treatments with the $POCI_3$ flow rate.

• Journal of the Korean institute of surface engineering
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• v.49 no.6
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• pp.490-497
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• 2016

In this study, 3-dimensional ripple structured anion (chlorine) doped ZnO thin film are developed, and used as electron transporting layer (ETL) in inverted organic photovoltaics (I-OPVs). Optical and electrical characteristics of ZnO:Cl ETL are investigated depending on the chlorine doping ratio and optimized for high efficient I-OPV. It is found that optimized chlorine doping on ZnO ETL enhances the ability of charge transport by modifying the band edge position and carrier mobility without decreasing the optical transmittance in the visible region, results in improvement of power conversion efficiency of I-OPV. The highest performance of 8.79 % is achieved for I-OPV with ZnO:Cl-x (x=0.5wt%), enhanced ~10% compared to that of ZnO:Cl-x (x=0wt%).

• Current Photovoltaic Research
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• v.2 no.3
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• pp.120-123
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• 2014

Thermal doping method using furnace is generally used for solar-cell wafer doping. It takes a lot of time and high cost and use toxic gas. Generally selective emitter doping using laser, but laser is very high equipment and induce the wafer's structure damage. In this study, we apply atmospheric pressure plasma for solar-cell wafer doping. We fabricated that the atmospheric pressure plasma jet injected Ar gas is inputted a low frequency (1 kHz ~ 100 kHz). We used shallow doping wafers existing PSG (Phosphorus Silicate Glass) on the shallow doping CZ P-type wafer (120 ohm/square). SIMS (Secondary Ion Mass Spectroscopy) are used for measuring wafer doping depth and concentration of phosphorus. We check that wafer's surface is not changed after plasma doping and atmospheric pressure doping width is broaden by increase of plasma treatment time and current.

• Bulletin of the Korean Chemical Society
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• v.33 no.1
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• pp.199-203
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• 2012

A modified sol-gel method and $N_2$-plasma treatment were used to prepare bulk and surface doped N-$TiO_2$, respectively. XRD, TEM, UV-vis spectroscopy, $N_2$ adsorption, Elemental Analyzer, Photoluminescence, and XP spectra were used to characterize the prepared $TiO_2$ samples. The N doping did not change the phase composition and particle sizes of $TiO_2$ samples, but increased the visible light absorption. The photocatalytic activities were tested in the degradation of an aqueous solution of a reactive dyestuff, methylene blue, under visible light. The photocatalytic activity of surface doped N-$TiO_2$ prepared by $N_2$-plasma was much higher than that of bulk doped N-$TiO_2$ prepared by sol-gel method. The possible mechanism for the photocatalysis was proposed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.553-556
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• 1999

This paper presents a proper condition to achieve above 19 % conversion efficiency using PC1D simulator. Cast poly-Si wafers with resistivity of 1 $\Omega$-cm and thickness of 250 ${\mu}{\textrm}{m}$ were used as a starting material. Various efficiency influencing parameters such as rear surface recombination velocity and minority carrier diffusion length in the base region, front surface recombination velocity, junction depth and doping concentration in the Emitter layer, BSF thickness and doping concentration were investigated. Optimized cell parameters were given as rear surface recombination of 1000 cm/s, minority carrier diffusion length in the base region 200 ${\mu}{\textrm}{m}$, front surface recombination velocity 100 cnt/s, sheet resistivity of emitter layer 100 $\Omega$/$\square$, BSF thickness 5 ${\mu}{\textrm}{m}$, doping concentration 5$\times$10$^{19}$ cm$^3$ . Among the investigated variables, we learn that a diffusion length of base layer acts as a key factor to achieve conversion efficiency higher than 19 %. Further details of simulation parameters and their effects to cell characteristics are discussed in this paper.

• Transactions on Electrical and Electronic Materials
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• v.6 no.6
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• pp.245-248
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• 2005

The physical and electrical properties of polycrystalline $\beta$-SiC were studied according to different nitrogen doping concentration. Nitrogen-doped SiC films were deposited by LPCVD(1ow pressure chemical vapor deposition) at $900^{\circ}C$ and 2 torr using $100\%\;H_2SiCl_2$ (35 sccm) and $5 \%\;C_2H_2$ in $H_2$(180 sccm) as the Si and C precursors, and $1\%\;NH_3$ in $H_2$(20-100 sccm) as the dopant source gas. The resistivity of SiC films decreased from $1.466{\Omega}{\cdot}cm$ with $NH_3$ of 20 sccm to $0.0358{\Omega}{\cdot}cm$ with 100 sccm. The surface roughness and crystalline structure of $\beta$-SiC did not depend upon the dopant concentration. The average surface roughness for each sample 19-21 nm and the average surface grain size is 165 nm. The peaks of SiC(111), SiC(220), SiC(311) and SiC(222) appeared in polycrystalline $\beta$-SiC films deposited on $Si/SiO_2$ substrate in XRD(X-ray diffraction) analysis. Resistance of nitrogen-doped SiC films decreased with increasing temperature. The variation of resistance ratio is much bigger in low doping, but the linearity of temperature dependent resistance variation is better in high doping. In case of SiC films deposited with 20 sccm and 100 sccm of $1\%\;NH_3$, the average of TCR(temperature coefficient of resistance) is -3456.1 ppm/$^{\circ}C$ and -1171.5 ppm/$^{\circ}C$, respectively.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.156-156
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• 2016

The effect of nitrogen doping on the mechanical and tribological performance of single-layer tetrahedral amorphous carbon (ta-C:N) coatings of up to $1{\mu}m$ in thickness was investigated using a custom-made filtered cathode vacuum arc (FCVA). The results obtained revealed that the hardness of the coatings decreased from $65{\pm}4.8GPa$ to $25{\pm}2.4GPa$ with increasing nitrogen gas ratio, which indicates that nitrogen doping occurs through substitution in the $sp^2$ phase. Subsequent AES analysis showed that the N/C ratio in the ta-C:N thick-film coatings ranged from 0.03 to 0.29 and increased with the nitrogen flow rate. Variation in the G-peak positions and I(D)/I(G) ratio exhibit a similar trend. It is concluded from these results that micron-thick ta-C:N films have the potential to be used in a wide range of functional coating applications in electronics. To achieve highly conductive and wear-resistant coatings in system components, the friction and wear performances of the coating were investigated. The tribological behavior of the coating was investigated by sliding an SUJ2 ball over the coating in a ball-on-disk tribo-meter. The experimental results revealed that doping using a high nitrogen gas flow rate improved the wear resistance of the coating, while a low flow rate of 0-10 sccm increased the coefficient of friction (CoF) and wear rate through the generation of hematite (${\alpha}-Fe_2O_3$) phases by tribo-chemical reaction. However, the CoF and wear rate dramatically decreased when the nitrogen flow rate was increased to 30-40 sccm, due to the nitrogen inducing phase transformation that produced a graphite-like structure in the coating. The widths of the wear track and wear scar were also observed to decrease with increasing nitrogen flow rate. Moreover, the G-peaks of the wear scar around the SUJ2 ball on the worn surface increased with increasing nitrogen doping.

• Journal of the Korean Ceramic Society
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• v.54 no.3
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• pp.243-248
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• 2017

Pd-doped $SnO_2$ thick film with a pure tetragonal phase was prepared on patterned Pt electrodes by an ink dropping method. Nanostructured $SnO_2$ powder with a diameter of 10 nm was obtained by a modified hydrazine method. Then the ink solution was fabricated by mixing water, glycerol, bicine and the Pd-doped $SnO_2$ powder. When the Pd doping concentration was increased, the grain size of the Pd-doped $SnO_2$ thick film became smaller. However, an agglomerated and extruded surface morphology was observed for the films with Pd addition over 4 wt%. The orthorhombic phase disappeared even at a low Pd doping concentration and a PdO peak was obtained for a high Pd doping concentration. The crack-free Pd-doped $SnO_2$ thick films were able to successfully fill the $30{\mu}m$ gap of the patterned Pt electrodes by the optimized ink dropping method. The prepared 3 wt% Pd-doped $SnO_2$ thick films showed monoxide gas responses ($R_{air}/R_{CO}$) of 4.0 and 35.6 for 100 and 5000 ppm, respectively.

• Journal of Sensor Science and Technology
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• v.17 no.4
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• pp.256-260
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• 2008

This paper describes the mechanical properties of poly(polycrystalline) 3C-SiC thin films with various doping concentration, in which poly 3C-SiC thin fil's mechanical properties according to the n-doping concentration 1($9.2{\times}10^{15}cm^{-3}$), 3($5.2{\times}10^{17}cm^{-3}$), and 5%($6.8{\times}10^{17}cm^{-3}$) respectively were measured by nano indentation. In the case of $9.2{\times}10^{15}cm^{-3}n$-doping concentration, Young's modulus and hardness were obtained as 270 and 30 GPa, respectively. When the surface roughness according to n-doping concentrations was investigated by AFM(atomic force microscope), the roughness of poly 3C-SiC thin films doped by 5% concentration was 15 nm, which is also the best of them.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.95-97
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• 2004

We studied a low temperature ion doping process for poly-Si Thin Film Transistor (TFT) on plastic substrates. The ion doping process was performed using an ion shower system, and subsequently, excimer laser annealing (ELA) was done for the activation. We have studied the crystallinity of Si surface at each step using UV-reflectance spectroscopy and the sheet resistance using 4-point probe. We found that the temperature has increased during ion shower doping for a-Si film and the activation has not been fulfilled stably because of the thermal damage against the plastic substrate. By trying newly a pulsed ion shower doping, the ion was efficiently incorporated into the a-Si film on plastic substrate. The sheet resistance decreased with the increase of the pulsed doping time, which was corresponded to the incorporated dose. Also we confirmed a relationship between the crystallinity and the sheet resistance. A sheet resistance of 300 ${\Omega}$/sq for the Si film of 50nm thickness was obtained with a good reproducibility. The ion shower technique is a promising doping technique for ultra low temperature poly-Si TFTs on plastic substrates as well as those on glass substrates.