• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1311-1314
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• 2008

We have developed new electrical dopants of rhenium oxide ($ReO_3$) and cupper iodide (CuI) as p-dopants and rubidium carbonate ($Rb_2CO_3$) as an n-dopant, respectively. $ReO_3$ has advantage of low temperature evaporation (about $300^{\circ}C$) with enhanced device stability. Various kinds of high performance organic light emitting diodes have been realized, including bottom emission, tandem, and top-emission OLEDs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.68-69
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• 2007

To make cost-effective solar cells, We have to use low cost material or make short process time or high temperature process. In solar cells, formation of emitter is basic and important technique according to build-up P-N junction. Diffusion process using spin-on dopants has all of this advantage. In this paper, We investigated n+ emitter formation spin-on dopants to apply crystalline silicon solar cells. We known variation of sheet resistance according to variation of temperature and single-crystalline and multi-crystalline silicon wafer using Honeywell P-8545 phosphorus spin-on dopants. We obtain uniformity of sheet resistance within 3~5% changing RPM of spin coater.

• Journal of the Korean Electrochemical Society
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• v.6 no.2
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• pp.134-140
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• 2003

Stretchable Polypyrrole films(Ppy-DBSA, Ppy-mixed dopants) using functionalized doping agents dodecyl-benzensulfonic acid (DBSA) and mixed dopants{DBSA with $LIClO_4$, NSA (2-naphthalenesulfonic acid), DEHSA [di(2-ethylhexyl)sulfosuccinic acid]}, were synthesized by electrochemical method. Electrochemically prepared Polypyrrole films were stretch-oriented $(L/L_0=1.0-2.5)$ by a Bone drawing method and their electrical conductivities were measured. As the drawing ratio was increased, the electrical conductivities were increased. This results might be due to the increase in crystallinity through the incresase in draw ratio. The results of temperature dependence of electrical conductivity showed that power raw $(L/L_0=1.0-2.5)$ gave the best fit to the data for stretched Ppy-DBSA and Ppy-mixed dopants films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.368-368
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• 2007

Zinc oxide (ZnO) has drawn much interest as a potential transparent conducting oxide (TCO) for applying to solar cell and front electrode of electro-luminescent devices. For the enhancement of electrical property of TCOs, dopant introduction and hybridization with conductive nanoparticles have been investigated. In this work, ZnO films were formed on glass substrate by using photochemical solution deposition of Ag nanoparticles dispersed or various metal (Ag, Cd, In, or Sn) contained photosensitive ZnO solutions. The usage of photosensitive solution permits us to obtain a micron-sized direct patterning of ZnO film without using conventional dry etching procedure. The structural, optical, and electrical characteristics of ZnO films with the introduction of metal dopants with/without Ag nanoparticles have been investigated to check whether there is a combined effect between metal dopants and Ag nanoparticles on the characteristics of ZnO film. The phase formation and crystallinity of ZnO film were monitored with X-ray diffractometer. The optical transmittance measurement was carried out using UV-VIS-NIR spectrometer and the electrical properties such as sheet resistance and conductivity were observed by using four-point probe.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.9
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• pp.724-727
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• 2009

We have fabricated (Ba,Sr)TiO3$TiO_3$ thick films doped with various amount of ZnBO dopants (1, 3, and 5 wt%) by screen printing method on the alumina substrates, which were sintered at the temperature below $1200^{\circ}C$. With increasing the amount of ZnBO dopants, the relative dielectric permittivity of ZnBO doped (Ba,Sr)$TiO_3$ was decreased, while loss tangent was increased. 1 wt% ZnBO doped (Ba,Sr)$TiO_3$ thick film has relative dielectric permittivity of 759 at 1 MHz, while 3 and 5 wt% of ZnBO doped (Ba,Sr)$TiO_3$ thick films have 624 and 554, respectively. By introducing ZnBO dopants to the (Ba,Sr)$TiO_3$ thick films, leakage current densities were decreased. The decreased leakage current with increasing ZnBO dopants can be explained by increased density and grain size of thick film on alumina substrate. We believe this decreased leakage current density probably come from the increased grain size and increased density.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.289-289
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• 2007

Spinel structured $LiMn_2O_4$ is more economic and environmental friendly to be used as commercial active material for secondary battery compared to Co-oxide material active material, but spinel structure of $LiMn_2O_4$ is unstable and its capacitance decreases with increase of cycle. Therefore, the purpose of our sturdy is to improve the stability of $LiMn_2O_4$ spinel structure and increase its capacitance by using substituents or dopants. $LiMn_2O_4$ powder was synthesized by charging substituents or dopants mole fractions, and temperatures. Crystal state, structure and specific surface area of the synthesized powder were measured and also characteried electrochemically by measuring its impedance, charge-discharge capacitance and etc.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.7
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• pp.691-696
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• 2004

The electronic state and chemical bonding of $\beta$-MnO$_2$ with transition metal dopants were theoretically investigated by DV-X$_{\alpha}$ (the discrete variational X$_{\alpha}$) method, which is a sort of the first principles molecular orbital method using the Hartree-Fock-Slater approximation. The calculations were performed with a $_Mn_{14}$ MO$_{56}$ )$^{-52}$ (M = transition metals) cluster model. The electron energy level, the density of states (DOS), the overlap population, the charge density distribution, and the net charges, were calculated. The energy level diagram of MnO$_2$ shows the different band structure and electron occupancy between the up spin states and down spin states. The dopant levels decrease between the conduction band and the valence band with the increase of the atomic number of dopants. The covalency of chemical bonding was shown to increase and ionicity decreased in increasing the atomic number of dopants. Calculated results were discussed on the basis of the interaction between transition metal 3d and oxygen 2p orbital. In conclusion it is expected that when the transition metals are added to MnO$_2$ the band gap decreases and the electronic conductivity increases with the increase of the atomic number of dopants. the atomic number of dopants.

• Journal of information and communication convergence engineering
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• v.1 no.2
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• pp.67-69
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• 2003

The experimental studies for the etch properties of the oxide grown on silicon substrate, which is in diluted hydrogen fluoride (HF) solution, are presented. Using different ion implantation dosages, dopants and energies, silicon substrate was implanted. The wet etching in diluted HF solution is used as a mean of wafer cleaning at various steps of VLSI processing. It is shown that the wet etch rate of oxide grown on various implanted silicon substrates is a strong function of ion implantation dopants, dosages and energies. This phenomenon has never been reported before. This paper shows that the difference of wet etch rate of oxide by ion implantation conditions is attributed to the kinds and volumes of dopants which was diffused out into $SiO_2$ from implanted silicon during thermal oxidation.

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1205-1211
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• 2013

The structural and optical properties of the ZnO, Al-doped ZnO, Ga-doped ZnO, and In-doped ZnO nanorods were investigated using field-emission scanning electron microscopy, X-ray diffraction, photoluminescence (PL) and ultraviolet-visible spectroscopy. All the nanorods grew with good alignment on the ZnO seed layers and the ZnO nanorod dimensions could be controlled by the addition of the various dopants. For instance, the diameter of the nanorods decreased with increasing atomic number of the dopants. The ratio between the near-band-edge emission (NBE) and the deep-level emission (DLE) intensities ($I_{NBE}/I_{DLE}$) obtained by PL gradually decreased because the DLE intensity from the nanorods gradually increased with increase in the atomic number of the dopants. We found that the dopants affected the structural and optical properties of the ZnO nanorods including their dimensions, lattice constants, residual stresses, bond lengths, PL properties, transmittance values, optical band gaps, and Urbach energies.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.8
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• pp.658-666
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• 2000

Sb and Sb-Fe doped SnO$_2$film resistors were prepared by spray pyrolysis technique. The effects of Sb and Sb-Fe addition on TCR and electrical properties of SnO$_2$film resistors were studied. Also the dependence of electrical properties on the substrate temperature and substrate-nozzle distance was investigated. The Sn-Sb system with 7.9 mol% SbCl$_3$(STO-406) and Sn-Sb-Fe systems with 7.3 mol% SbCl$_3$+7.3 mol% FeCl$_3$(STO-407) and with 3.4 mol% SbCl$_3$+7.7mol% FeCl$_3$(STO-408) were prepared. Both of the systems Sn-Sb and Sn-Sb-Fe represented nonlinearity of TCR with temperature. As the amount of Fe increased TCR was shifted to positive direction. Decreasing Sb or increasing Fe caused resistivity to increase. Also increasing Fe caused the crystallization degree of rutile structure in SnO$_2$film to decrease. The electrical resistivity decreased with increasing substrate temperature The resistivity decreased with increasing substrate-nozzle distance in the ranges from 15 to 25 cm and increased rapidly at the distance over 25cm.