• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1845-1847
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• 2013

The lateral photovoltaic effect (LPE) can be observed in semiconductors by irradiating a light spot position between electrodes on sample's surface. Because lateral photovoltaic voltage (LPV) is sensitively changed by light spot position, a LPE device has been tried as a position-sensitive detector. This study discusses the correlation between LPV and conductivity in p-type silicon and nano-structured Au deposited p-type silicon (nano-Au silicon), respectively. Conductivity measurement of the sample was carried out using the four-wire method to eliminate contact resistance, and conductivity dependence on LPV was simultaneously measured by changing the light irradiation position. The result showed a strong correlation between conductivity and LPV in the p-type silicon sample. The correlation coefficient was 0.87. The correlation coefficient between LPV and conductivity for the nano-Au silicon sample was 0.41.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.909-912
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• 2001

Lanthanide orthochromite materials have been widely studied as refractory conducting ceramics because of their electrical conductivity, oxidation resistance and high melting points. In this paper theoretical and experimental analysis about electric conductivity of the SHS prepared ceramics was carried out. The usefulness of the Seebeck-coefficient measurements as a function of P(O$_2$) is emphasized. Electronic conduction was found to be n-type in the lower P(O$_2$) range, and p-type in the higher P(O$_2$) range. The carrier concentrations were calculated as a function of P(O$_2$) and defect structure.

• 한국세라믹학회지
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• 제37권5호
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• pp.432-437
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• 2000

Thermoelectric properties of p-type SiGe alloys prepared by a RF inductive furnace were investigated. Non-doped Si80Ge20 alloys were fabricated by control of the quantity of volatile Ge. The carrier of p-type SiGe alloy was controlled by B-doping. B doped p-type SiGe alloys were synthesized by melting the mixture of Ge and Si containing B. The effects of sintering/annealing conditions and compaction pressure on thermoelectric properties (electrical conductivity and Seebeck coefficient) were investigated. For nondoped SiGe alloys, electrical conductivity increased with increasing temperatures and Seebeck coefficient was measured negative showing a typical n-type semiconductivity. On the other hand, B-doped SiGe alloys exhibited positive Seebeck coefficient and their electrical conductivity decreased with increasing temperatures. Thermoelectric properties were more sensitive to compaction pressure than annealing time. The highest power factor obtained in this work was 8.89${\times}$10-6J/cm$.$K2$.$s for 1 at% B-doped SiGe alloy.

• The Korean Journal of Ceramics
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• 제4권2호
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• pp.68-71
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• 1998

The effect of Mn and Nb additions on the electrical properties of BaTiO$_3$ has been studied by means of equilibrium electrical conductivity as a function of temperature, oxygen partial pressure(Po$_2$) and composition. If the manganese ion is added to the normal Ti site, i.e. BaTi$_{1-x}Mn_xO_{\delta-6}$, the equilibrium conductivity shows strong evidence of acceptor-doped behavior. The conductivity minimum, corresponding to the transition from oxygen excess, p-type behavior to oxygen deficient, n-type behavior with decreasing Po$_2$, is displaced to lower Po$_2$ and is broadened and flattened. The partial replacement of Mn ion with Nb decreases the acceptor-doped effect and the total replacement exhibits a typical donor-doped behavior. It was confirmed that unlike undoped or other acceptor-doped behavior. It was confirmed that unlike undoped or other acceptor-doped samples, for the p-type region, the electrical conductivity follows the 1/6th power dependence of oxygen partial pressure.

• 대한금속재료학회지
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• 제56권11호
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• pp.822-828
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• 2018

P-type Ce/Yb-filled skutterudites were synthesized, and their charge transport and thermoelectric properties were investigated with partial double filling and charge compensation. In the case of $(Ce_{1-z}Yb_z)_{0.8}Fe_4Sb_{12}$ without Co substitution, the marcasite ($FeSb_2$) phase formed alongside the skutterudite phase, but the generation of the marcasite phase was inhibited by increasing Co concentration. The electrical conductivity decreased with increasing temperature, exhibiting degenerate semiconductor behavior. The Hall and Seebeck coefficients were positive, which confirmed that the specimens were p-type semiconductors with holes as the major carriers. The carrier concentration decreased as the concentration of Ce and Co increased, which led to decreased electrical conductivity and increased Seebeck coefficient. The thermal conductivity decreased due to a reduction in electronic thermal conductivity via Co substitution, and due to decreased lattice thermal conductivity via double filling of Ce and Yb. $(Ce_{0.25}Yb_{0.75})_{0.8}Fe_{3.5}Co_{0.5}Sb_{12}$ exhibited the greatest dimensionless figure of merit (ZT = 0.66 at 823 K).

• The Korean Journal of Ceramics
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• 제1권1호
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• pp.21-28
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• 1995

Electrical conductivity of $TiO_2$ thin films, deposited on $Al_2O_3$ substrates by metal organic chemical vapor deposition (MOCVD), was measured by four-point probe method in a temperature range from $800^{\circ}C$ to $1025^{\circ}C$ and an oxygen partial pressure range from $2.7{\times}10^{-5}$ atm to 1 atm. In the low oxygen partial pressure region n-type conduction was dominant, but in the high oxygen partial pressure region p-type conduction behavior appeared due to substitution of Ti ions by Al ions, which were diffused from the substrate during post deposition annealing process. Electrical conductivity of the film decreases in the n-type region and increases in the p-type region as the oxygen partial pressure increases. The transition points, which show the minimum conductivity, shifted to the higher oxygen partial pressure region as the measuring temperature increased, but it shifted to lower oxygen partial pressure region with an increase in the post annealing temperature. The results were also discussed with the possible defect models.

• 한국전기전자재료학회논문지
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• 제20권3호
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• pp.202-206
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• 2007

ZnO is a promising material to make high efficient ultraviolet(UV) or blue light emitting diodes(LEDs) because of its large binding energy and energy bandgap. In this study, we prepared ZnO thin films with p-type conductivity on silicon(100) substrates by RF magnetron sputtering in the mixture of $N_2$ and $O_2$. The process was accompanied by low pressure in-situ annealing in $O_2$ at $600^{\circ}C$ and $800^{\circ}C$ respectively. Hall effect in Van der Pauw configuration showed that the N-doped ZnO film annealed at $800^{\circ}C$ has p-type conductivity. Photoluminescence(PL) spectrum of the film annealed at $800^{\circ}C$ showed UV emission related to exciton and bound to donor-acceptor pair(DAP) as well as visible emission related to many intrinsic defects.

• 반도체디스플레이기술학회지
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• 제11권4호
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• pp.19-23
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• 2012

We report microbolometer characteristic with n-type and p-type amorphous silicon thin film. The n-type and p-type amorphous silicon thin films were made by PECVD. The electrical properties of n-type and p-type a-Si:H thin films were investigated as a function of doping gas flow rate. The doping gas used $B_2H_6/Ar$ (1:9) and $PH_3/Ar$ (1:9). In general, the conductivity of doping a-Si:H thin films increased as doping gas increase but the conductivity of a-Si:H thin films decreased as the doping gas increase because doping gas concentration increase led to dilution gas (Ar) increase as the same time. We fabricated an amorphous silicon microbolometer using surface micromachining technology. The fabricated microbolometer had a negative TCR of 2.3%. The p-type microbolometer had responsivity of $5{\times}10^4V/W$ and high detectivity of $3{\times}10^8cm(Hz)^{1/2}/W$. The p-type microbolometer had more detectivity than n-type for less noise value.

• Journal of Magnetics
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• 제12권4호
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• pp.144-148
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• 2007

We report on the observation of p-type conductivity and ferromagnetism in diluted magnetic semiconductor $(Zn_{0.97}Mg_{0.01}Mn_{0.02})O:P$ films grown on $SiO_2/Si$ substrates by pulsed laser deposition. The p-type conduction with hole concentration over $10^{18}cm^{-3}$ is obtained by codoping of Mg and P followed by rapid thermal annealing in an $O_2$ atmosphere. Structural and compositional analyses for the p-type $(Zn_{0.97}Mg_{0.01}Mn_{0.02})O:P$ films annealed at $800^{\circ}C$ indicates that highly c-axis oriented homogeneous films were grown without any detectable formation of secondary phases. The films were found to be transparent in the visible range. The magnetic measurements clearly revealed an enhancement of room temperature ferromagnetism by p-type doping.

• 한국전기전자재료학회논문지
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• 제29권11호
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• pp.671-675
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• 2016

Skutterudite materials show PGEC (phonon glass electron crystal) characteristics which is an optimal strategy for designing high performance thermoelectric materials. Now two methods are in parallel to control thermal conductivity of skutterudites, a rattler-atoms doping method and a process for nanostructured bulk materials. Amount of rattler atoms in p-type skutterudite are depends on a Fe/Co ratio of matrix, and the optimal Fe/Co ratio has been reported about from 3:1 to 3.5:0.5 in $R(Fe,Co)_4Sb_{12}$ structure. In this paper, our discussion for rattler doping research was concentrated on double-rattler systems and DD-doped systems in p-type skutterudites. A melt spinning precess combined with high energy ball milling were suggested as a strategy for nanostructured bulk materials with PGEC (phonon glass electron crystal) characteristics in p-type skutterudites.