• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.149-153
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• 2011

The PC1D is widely used for modeling the properties of crystalline silicon solar cell. Optimized doping profile in crystalline silicon solar cell fabrication is necessary to obtain high conversion efficiency. Doping profile in the forms of a uniform, gaussian, exponential and erfc function can be simulated using the PC1D program. In this paper, the doping profiles including junction depth, dopant concentration on surface and the form of doping profile (gaussian, gaussian+erfc function) were changed to study its effect on electrical properties of solar cell. As decreasing junction depth and doping concentration on surface, electrical properties of solar cell were improved. The characteristics for the solar cells with doping profile using the combination of gaussian and erfc function showed better open-circuit voltage, short-circuit current and conversion efficiency.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.2
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• pp.73-80
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• 1990

The formation of Ti-silicides with the type of substrate, the species and the concentration of dopant, and the annealing temperature was investigated with sheet resistance and thickness measurement, elemental depth profilling, and microstructure. It was directly affected by the type of substrate, the species and the concentration of dopant, and the annealing temperature. For the amorphous Si substrate, the smothness of $TiSi_2/Si$ interface was increased. Above concentr-ation of $1{\times}10^{16}ions/cm^2$, the rate of $TiSi_2/Si$ formation was decreased and the sheet resistance was increased. The initial profile of dopant according to the implantation energy was one of the factors influencing the out-diffusion of dopant. In $POCI_3$ process, this was less than in ion implantation process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.6
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• pp.377-385
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• 2018

For the investigation of dopant profiles in implanted $Si_{1-x}Ge_x$, the implanted B and As profiles are measured using SIMS (secondary ion mass spectrometry). The fundamental ion-solid interactions of implantation in $Si_{1-x}Ge_x$ are discussed and explained using SRIM, UT-marlowe, and T-dyn programs. The annealed simulation profiles are also analyzed and compared with experimental data. In comparison with the SIMS data, the boron simulation results show 8% deviations of $R_p$ and 1.8% deviations of ${\Delta}R_p$ owing to relatively small lattice strain and relaxation on the sample surface. In comparison with the SIMS data, the simulation results show 4.7% deviations of $R_p$ and 8.1% deviations of ${\Delta}R_p$ in the arsenic implanted $Si_{0.2}Ge_{0.8}$ layer and 8.5% deviations of $R_p$ and 38% deviations of ${\Delta}R_p$ in the $Si_{0.5}Ge_{0.5}$ layer. An analytical method for obtaining the dopant profile is proposed and also compared with experimental and simulation data herein. For the high-speed CMOSFET (complementary metal oxide semiconductor field effect transistor) and HBT (heterojunction bipolar transistor), the study of dopant profiles in the $Si_{1-x}Ge_x$ layer becomes more important for accurate device scaling and fabrication technologies.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.735-738
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• 2003

In this paper, we report a molecular dynamics (MD) simulation of the ion implantation for nano-scale devices with ultra-shallow junctions. In order to model the profile of ion distribution in nanometer scale, the molecular dynamics with a damage model has been employed. As an exemplary case, we calculate the dopant profile during the ion implantation of B, As, and Ge.

• Current Photovoltaic Research
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• v.4 no.2
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• pp.31-41
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• 2016

n-type PERT (passivated emitter, rear totally diffused) bifacial solar cells with boron and phosphorus diffusion as p+ emitter and n+ BSF (back surface field) have attracted significant research interest recently. In this work, the influences of wafer thickness, bulk lifetime, emitter, BSF on the photovoltaic characteristics of solar cells are discussed. The performance of the solar cell is determined by using one-dimensional solar cell simulation software PC1D. The simulation results show that the key role of the BSF is to decrease the surface doping concentration reducing the recombination and thus, increasing the cell efficiency. A lightly phosphorus doped BSF (LD BSF) was experimentally optimized to get low surface dopant concentration for n type bifacial solar cells. Pre-oxidation combined with a multi-plateau drive-in, using limited source diffusion was carried out before pre-deposition. It could reduce the surface dopant concentration with minimal impact on the sheet resistance.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.11
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• pp.1001-1006
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• 2005

A new fabrication method is proposed to form the stacked polysilicon gate by nitridation in $N_2$ atmosphere using conventional LP-CVD system. Two step stacked layers with an amorphous layer on top of a polycrystalline layer as well as three step stacked layers with polycrystalline films were fabricated using the proposed method. SIMS profile showed that the proposed method would successfully create the nitrogen-rich layers between the stacked polysilicon layers, thus resulting in effective retardation of dopant diffusion. It was observed that the dopants in stacked films were piled-up at the interface. TEM image also showed clear distinction of stacked layers, their plane grain size and grain mismatch at interface layers. Therefore, the number of stacked polysilicon layers with different crystalline structures, interface position and crystal phase can be easily controlled to improve the device performance and reliability without any negative effects in nano-scale CMOSFETs.

• Macromolecular Research
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• v.11 no.6
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• pp.467-470
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• 2003

The dielectrophoretic technique was used to prepare density gradient polymers, polystyrene doped with a dipolar modifier, diphenyl sulfide. We have measured concentration gradients of the dopant by UV/Nis spectroscopy as a function of time in a nonuniform electric field. Measured concentration data at different positions of the sample confirmed that a concentration gradient arose after a nonuniform electric field was applied to the system, these data were used to compare the concentration profile with that predicted by the dielectrophoresis equation.

• Journal of the Korean Vacuum Society
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• v.4 no.S2
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• pp.90-94
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• 1995

Defects introduced by Si, Ge preamorphization and their effects on the dopant diffusion and electrical characteristics. Good crystalline quality are obtained after the annealing of Ge ion double implanted samples. The defect clusters under the a/c interface are expected to extend up to the deep in the Si ion implanted samples. The dislocation loops near the junction absorb the interstitial Si atoms resolving from the defect cluster and result in the prevention of enhanced boron diffusion near the tail region of boron profile and show good reverse current charactristics.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.6
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• pp.95-99
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• 2013

Furnace is currently the most important doping process using POCl3 in solar cell. However furnace need an expensive equipment cost and it has to purge a poisonous gas. Moreover, furnace typically difficult appling for selective emitters. In this study, we developed a new atmospheric pressure plasma source, in this procedure, we research the atmospheric pressure plasma doping that dopant is phosphoric acid($H_3PO_4$). Metal tube injected Ar gas was inputted 5 kV of a low frequency(scores of kHz) induced inverter, so plasma discharged at metal tube. We used the P type silicon wafer of solar cell. We regulated phosphoric acid($H_3PO_4$) concentration on 10% and plasma treatment time is 90 s, 150 s, we experiment that plasma current is 70 mA. We check the doping depth that 287 nm at 90 s and 621 nm at 150 s. We analysis and measurement the doping profile by using SIMS(Secondary Ion Mass Spectroscopy). We calculate and grasp the sheet resistance using conventional sheet resistance formula, so there are 240 Ohm/sq at 90 s and 212 Ohm/sq at 150 s. We analysis oxygen and nitrogen profile of concentration compared with furnace to check the doped defect of atmosphere.

• Journal of the Optical Society of Korea
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• v.18 no.6
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• pp.650-656
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• 2014

We propose a novel active fiber design for selectively generating cylindrical vector beams (CVBs) or cylindrical vector modes (CVMs) which can be applied to conventional fiber lasers. A fiber is designed to have a ring-shaped core refractive index profile which can lead to the best overlap between the active dopant distribution profile and the lowest-order CVM (LCVM) field profile. Therefore, the overlap factor (OVF) of the LCVM becomes even higher than that of the fundamental mode. We emphasize that this condition cannot be satisfied by a conventional step-index core fiber (SICF) but by the ring-doped core fiber (RDCF). Because the lasing threshold is inversely proportional to the OVF, the LCVM can predominantly be stimulated even without going through special procedures to impose extra loss mechanisms to the fundamental mode. We numerically verify that the OVF of the LCVM with the doped ions can significantly exceed that of the fundamental mode if the proposed fiber design is applied. In addition, an RDCF of the proposed fiber design can also operate in a regime containing no higher-order modes besides the LCVM, so that it can selectively and efficiently generate the LCVM without being disrupted by the parasitic lasing of the higher-order modes. We highlight that an optimized RDCF can lead to a >30 % higher OVF ratio than a SICF having the same doped area. The proposed model is expected to be useful for enhancing the efficiency of generating CVBs in an all-fiber format.