• 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.

• 마이크로전자및패키징학회지
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• 제15권4호
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• pp.93-100
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• 2008

고온 발전용 열전모듈을 p-type으로는 $Ca_{2.7}Bi_{0.3}Co_4O_9$, n-type으로는 $Ca_{0.96}Bi_{0.04}Mn_{0.96}Nb_{0.04}O_3$을 선택하고 알루미나 기판 위에 1쌍과 2쌍을 제조하였다. 산화물 열전 모듈의 최적화 설계를 위해 먼저 1쌍의 열전모듈의 실험 결과로부터 전극의 접촉저항을 산출하여 2쌍 모듈에 적용함으로써 저항과 출력 특성을 예측하였다. 예측된 2쌍 모듈의 계산 값과 제조된 2쌍 모듈의 실측 값을 비교함으로써 모듈 설계를 위한 접근방법을 검토하였다. 2쌍 모듈의 계산된 저항과 측정된 저항은 각각 $T_h$=833 K에서 0.954 $\Omega$과 1.105 $\Omega$으로 약 0.15 $\Omega$ 정도의 차이로 근접한 결과를 얻었으며, 제시된 방법으로 고온산화물 열전 모듈 제작에 유효하다고 판단된다.

• 한국전기전자재료학회논문지
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• 제22권5호
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• pp.443-447
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• 2009

Bismuth-antimony-telluride based thermoelectric thin film materials were prepared by metal organic vapor phase deposition using trimethylbismuth, triethylantimony and diisopropyltelluride as metal organic sources. A planar type thermoelectric device has been fabricated using p-type $Bi_{0.4}Sb_{1.6}Te_3$ and n-type $Bi_{2}Te_{3}$ thin films. Firstly, the p-type thermoelectric element was patterned after growth of $5{\mu}m$ thickness of $Bi_{0.4}Sb_{1.6}Te_3$ layer. Again n-type $Bi_{2}Te_{3}$ film was grown onto the patterned p-type thermoelectric film and n-type strips are formed by using selective chemical etchant for $Bi_{2}Te_{3}$. The top electrical connector was formed by thermally deposited metal film. The generator consists of 20 pairs of p- and n-type legs. We demonstrate complex structures of different conduction types of thermoelectric element on same substrate by two separate runs of MOCVD with etch-stop layer and selective etchant for n-type thermoelectric material. Device performance was evaluated on a number of thermoelectric devices. To demonstrate power generation, one side of the device was heated by heating block and the voltage output was measured. The highest estimated power of 1.3 ${\mu}m$ is obtained at the temperature difference of 45 K.

• 한국분말재료학회지
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• 제30권2호
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• pp.130-139
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• 2023

Thermoelectric materials and devices are energy-harvesting devices that can effectively recycle waste heat into electricity. Thermoelectric power generation is widely used in factories, engines, and even in human bodies as they continuously generate heat. However, thermoelectric elements exhibit poor performance and low energy efficiency; research is being conducted to find new materials or improve the thermoelectric performance of existing materials, that is, by ensuring a high figure-of-merit (zT) value. For increasing zT, higher σ (electrical conductivity) and S (Seebeck coefficient) and a lower κ (thermal conductivity) are required. Here, interface engineering by atomic layer deposition (ALD) is used to increase zT of n-type BiTeSe (BTS) thermoelectric powders. ALD of the BTS powders is performed in a rotary-type ALD reactor, and 40 to 100 ALD cycles of ZnO thin films are conducted at 100℃. The physical and chemical properties and thermoelectric performance of the ALD-coated BTS powders and pellets are characterized. It is revealed that electrical conductivity and thermal conductivity are decoupled, and thus, zT of ALD-coated BTS pellets is increased by more than 60% compared to that of the uncoated BTS pellets. This result can be utilized in a novel method for improving the thermoelectric efficiency in materials processing.

• 대한기계학회논문집B
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• 제41권3호
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• pp.199-204
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• 2017

열전소자를 이용하여 고온의 표면을 능동적으로 냉각하여 적외선 방사량을 줄이는 기술을 소개한다. 공력가열이나 자체 발열 등에 의한 고온 표면 환경을 구현하였고, 여기에 열전소자를 설치하여 냉각하였을 때의 표면 온도와 적외선 방사량을 상용 수치해석 소프트웨어를 사용하여 계산하였다. 이를 통해 특정 환경에서 열전냉각소자를 이용하여 고온 표면에 있어 외부 환경과 비교했을 때의 적외선 방사량 대비를 이론적으로 완전히 제거할 수 있음을 확인하였다.

• 설비공학논문집
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• 제22권1호
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• pp.1-12
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• 2010

An analysis model considered the manufacturing factors and the pellet size has been developed in order to predict the performance characteristics of thermoelectric modules as generators. Since the electrical internal resistance has a significant role in the performance of thermoelectric modules, the variations of electrical internal resistance with operating temperature are experimentally measured. The modified electrical internal resistance calculated from an experimental correlation is applied to the analysis model. To verify the modified analysis model, the output voltage, output current and output power are compared with experimental results for the operating temperature conditions of $T_h=85^{\circ}C$ and ${\Delta}T=40^{\circ}C$. The modified analysis shows a good agreement with the experimental results in terms of the output voltage, current, and power.

• Journal of Power Electronics
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• 제15권4호
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• pp.899-909
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• 2015

A dual-input boost-buck converter with coupled inductors (DIBBC-CI) is proposed as a thermoelectric generator (TEG) power conditioner with a wide input voltage range. The DIBBC-CI is built by cascading two boost cells and a buck cell with shared inverse coupled filter inductors. Low current ripple on both sides of the TEG and the battery are achieved. Reduced size and power losses of the filter inductors are benefited from the DC magnetic flux cancellation in the inductor core, leading to high efficiency and high power density. The operational principle, impact of coupled inductors, and design considerations for the proposed converter are analyzed in detail. Distributed maximum power point tracking, battery charging, and output control are implemented using a competitive logic to ensure seamless switching among operational modes. Both the simulation and experimental results verify the feasibility of the proposed topology and control.

• 마이크로전자및패키징학회지
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• 제15권1호
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• pp.1-6
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• 2008

칼슘 코발트 층상 산화물계에서 $Ca_3Co_2O_6$와 $Ca_3Co_4O_9$를 기본으로 하여 열전 특성 향상을 위해 Ca 위치를 Bi, Sr, La, K로 부분 치환하고, Co위치를 Mn, Fe, Ni, Cu, Zn로 치환한 다결정 산화물을 제조하여 $300{\sim}1000K$ 까지의 열전 특성을 분석하였다. Bi가 치환된 $Ca_3Co_4O_9$계의 $Ca_{2.7}Bi_{0.3}Co_4O_9$는 전기전도도 $85.4({\Omega}cm)^{-1}, Seebeck계수 $176.2{\mu}V/K$그리고 파워팩터 $265.2{\mu}W/K^m$로 가장 높은 열전 물성치가 관찰되었다. 열전 모듈 제조를 위해서 각각의 열전반도체의 성능지수Z($10^{-4}/K$)가 0.87, 0.41의 값인 p형 열전 소재로 $Ca_{2.7}Bi_{0.3}Co_4O_9$를, n형 열전 소재로($Zn_{0.98}Al_{0.02}$)O를 선택하여 열전쌍을 제조하였다. 제조된 2쌍의 기본 열전쌍은 120K의 온도차에서 약 30mV정도의 기전력이 나타났다.

• 마이크로전자및패키징학회지
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• 제25권3호
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• pp.67-74
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• 2018

두께 $2.5{\sim}10{\mu}m$인 n형 $Bi_2Te_3$와 p형 $Sb_2Te_3$ 레그 8쌍으로 구성되어 있는 in-plane형 열전박막소자를 전기도금법으로 Si submounts에 형성하고, LED 칩의 구동에 의해 발생하는 겉보기 온도차 ${\Delta}T$와 레그 두께에 따른 발전특성을 분석하였다. LED 방출열에 의해 인가된 ${\Delta}T$가 7.4K일 때 각기 두께 $2.5{\mu}m$, $5{\mu}m$ 및 $10{\mu}m$의 p-n 레그들로 구성된 열전박막소자는 6.1 mV, 7.4 mV 및 11.8 mV의 open circuit 전압을 나타내었으며, 6.6 nW, 12.8 nW 및 41.9 nW의 최대 출력전력을 나타내었다.

• 마이크로전자및패키징학회지
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• 제26권4호
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• pp.119-126
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• 2019

18쌍의 Bi₂Te₃계 p-n 가압소결체 열전레그들로 구성되어 있으며 상하부 기판이 없고 내부는 polydimethylsiloxane (PDMS)로 충진되어 있는 유연열전모듈을 형성하고, 이의 발전특성과 굽힘특성을 분석하였다. 유연열전모듈을 팔목에 부착하였을 때 서있는 정적인 상태에서는 2.23 mV의 open circuit 전압과 1.69 ㎼의 최대출력전력이 얻어졌으며, 걸어가는 동적인 상태에서는 3.32 mV의 open circuit 전압과 3.41 ㎼의 최대출력전력이 얻어졌다. 유연열전모듈에 굽힘곡률반경 25 mm로 30,000회까지 반복굽힘 싸이클을 인가하여도 저항변화율이 1% 미만으로 유지되었다.