• 한국전기전자재료학회논문지
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• 제35권5호
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• pp.419-430
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• 2022

Defects in solids play a vital role on thermoelectric properties through the direct impacts of electronic band structure and electron/phonon transports, which can improve the electronic and thermal properties of a given thermoelectric semiconductor. Defects in semiconductors can be divided into four different types depending on their geometric dimensions, and thus understanding the effects on thermoelectric properties of each type is of a vital importance. This paper reviews the recent advances in the various thermoelectric semiconductors through defect engineering focusing on the charge carrier and phonon behaviors. First, we clarify and summarize each type of defects in thermoelectric semiconductors. Then, we review the recent achievements in thermoelectric properties by applying defect engineering when introducing defects into semiconductor lattices. This paper ends with a brief discussion on the challenges and future directions of defect engineering in the thermoelectric field.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.27-28
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• 2009

• 대한기계학회논문집B
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• 제30권1호
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• pp.41-47
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• 2006

High resolution dopant profiling in semiconductor devices has been an intense research topic because of its practical importance in semiconductor industry. Although several techniques have already been developed. it still requires very expensive tools to achieve nanometer scale resolution. In this study we demonstrated a novel dopant profiling technique with nanometer resolution using very simple setup. The newly developed technique measures the thermoelectric voltage generated in the contact point of the SPM probe tip and MOSFET surface instead of electrical signals widely adopted in previous techniques like Scanning Capacitance Microscopy. The spatial resolution of our measurement technique is limited by the size of contact size between SPM probe tip and MOSFET surface and is estimated to be about 10 nm in this experiment.

• 한국산업융합학회 논문집
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• 제22권2호
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• pp.219-226
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• 2019

This paper describes the development of a 500W DC/DC converter for use with a thermoelectric module(TEM). A thermoelectric device is a structure in which a P-type semiconductor and an N-type semiconductor are electrically connected in series and thermally connected in parallel. There is a feature that an electromotive force is generated by making a temperature difference between both surfaces of a thermoelectric element. This feature can be used as a renewable power source without the need for fossil energy. The proposed converter boosts the low generation voltage of the thermoelectric element to secure the voltage for the grid connection. This converter is a combination of a resonant converter for boosting and a boost-converter for output voltage control. This structure has an advantage that a voltage can be stepped up at a high efficiency and precise output voltage control is possible. We carry out simulations and experiments to verify the validity.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
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• pp.50-53
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• 2001

The thermoelectric refrigeration technologies have no moving parts. compressor, or piping required. In this study, the basic capacity of thermoelectric devices and development on some thermoelectric refrigerator were reviewed and basic technical concepts related with many kinds of thermoelectric materials were discussed. Especially the result of performance test on thermoelectric refrigerator whose minimum temperature of $-2^{\circ}C$ was introduced briefly.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.251-251
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• 2009

The generation of energy and the cooling of system using thermoelectric semiconductor material have been in spotlight. Thermoelectric effect increases with the decrease of the thermal conductivity. In the thermoelectric devices, thermal conductivity is related to phonon scattering. Therefore, few studies have been conducted in the thermoelectric materials dispersed nano oxide particle for increasing the phonon scattering. However, core-shell structure which nano particle disperses in solvents and then which thermoelectric materials coated on the nano oxide particles has not been reported. In this study, we selected commercial nano powder such as $Al_2O_3$. This nano particle was about 20nm and was crushed aggregate by mechanical treatment. We have developed the effect of the dispersant and the solvent. The properties of particles were evaluated by SEM, TEM, particle size analysis, and BET. Dispersion and dispersion stability were evaluated by electronic microscope and turbidity.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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• pp.17-17
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• 2009

We report the invention of a direct growth method termed On-Film Formation of Nanowire (OFF-ON) for making high-quality single-crystal nanowires, i.e. Bi and $Bi_2Te_3$, without the use of conventional templates, catalysts, or starting materials. We have used the OFF-ON technique to grow single crystal semi-metallic Bi and compound semiconductor $Bi_2Te_3$ nanowires from sputtered Bi and BiTe films after thermal annealing, respectively. The mechanism for nanowire growth is stress-induced mass flow along grain boundaries in the polycrystalline films. OFF-ON is a simple but powerful method for growing perfect single-crystal semi-metallic and compound semiconductor nanowires of high aspect ratio with high crystallinity that distinguishes it from other competitive growth approaches that have been developed to date. Our results suggest that Bi and $Bi_2Te_3$ nanowires grown by OFF-ON can be an ideal material system for exploring their unique thermoelectric properties due to their high-quality single crystalline and high conductivity, which have consequence and relevance for high-efficiency thermoelectric devices.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.525-527
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• 2008

N-Type $SbI_3$-doped $95%{Bi_2}{Te_3}-5%{Bi_2}{Se_3}$ compounds were prepared by a gas atomization and Magnetic Pulsed Compaction process. The dynamic recrystallization and thermoelectric properties of the MPCed bulks with consolidation temperatures and times were investigated by a combination of microscopy, XRD and thermoelectric property testing. The microstructure of MPCed bulk shows homogeneous and fine distribution through consolidated bulks due to dynamic recrystallization during hot MPC. This research presented the challenges toward the successful consolidation of thermoelectric powder using magnetic pulsed compaction (MPC).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.21-24
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• 2000

Properties of thermoelectric power in PbS thin films by chemical bath deposition were investigated The qualified PbS thin film was gained with the amounts of Thiourea($4-8ml/{\ell}$ ), Triethanolamine (1-2ml) and NaOH(l0ml). The molecular ratio of Pb and S was 3 : 7. Satisfied crystallization rate and deposition rate of PbS were greater at $50^{\circ}C$ than at $30^{\circ}C$. The constant of thermoelectric power in PbS was nearly $ 500uv/^{\circ}k$. The PbS thin film was changed from p-type to n-type semiconductor at around $200^{\circ}C$. In case of heat treatment at $300^{\circ}C$, the sample kept the characteristic of p-type semiconductors up to $250^{\circ}C$.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.682-683
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• 2006

Thermoelectric conversion efficiency of thermoelectric elements can be increased by using a structure combining n-type and p-type semiconductors. From the above point of view, attention was directed at ZnO as a candidate n-type semiconductor material and investigations were made. As the result, a dimensionless figure of merit ZT close to 0.28 (1073K) was obtained for specimens produced by the PCS (Pulse Current Sintering) method with addition of specified quantities of $TiO_2$, CoO, and $Al_2O_3$ to ZnO. It was found that the interstitial $TiO_2$ in the ZnO restrains the grain growth and CoO acts onto the bond between grains. The influence of the inclusion of $TiO_2$ and CoO onto the sintering behavior also was investigated.