• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.11
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• pp.987-993
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• 2003

We fabricated thick film monopole antennas using Mo-doped BiNbO$_4$ ceramics and investigated their electrical properties as a function of the Mo-doping concentration. Compared with undoped BiNbO$_4$ ceramics, 10 at.% Mo-doping improved microwave dielectric properties of ceramics by increased sintered density as well as decreased space charge density. Further increase in the Mo-doping concentration caused formation of Bi$_2$MoO$_{6}$ phases, resulting in deterioration of the microwave characteristics. The gain and bandwidth of the ceramic monopole antenna were also greatly affected by the Mo-doping concentration. When Mo-doping concentration was 10 at.%, highest gain of -0.7dBi with lowest bandwidth of 30% at 2.3GHz was obtained.

• Journal of the Korean Chemical Society
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• v.63 no.2
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• pp.94-101
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• 2019

Nb, Mo-doped and Nb/Mo-codoped $VO_2(M)$ nanocrystallites with various doping levels were synthesized for the first time by a hydrothermal and post thermal transformation method. The reversible phase transition characteristics of those doped $VO_2(M)$ was comparatively investigated. Nb-doping of $VO_2(M)$ by this method resulted in a very efficient lowering of the transition temperature ($T_c$) with a rate of $-16.7^{\circ}C/at.%$ that is comparable to W-doping, while Mo-doping did not give a serious reduction of $T_c$ with only a rate of $-5.1^{\circ}C/at.%$. Nb/Mo-codoping gave a similar result to Nb-doping without a noticeable difference. The thin films of Nb-doped and Nb/Mo-codoped $VO_2(M)$ with a thickness of ca. 120 nm were prepared by a wet-coating of the nanoparticle-dispersed solutions. Those films showed a good thermochromic modulation of near infrared radiation with 30-35% for Nb-doped $VO_2(M)$ and 37-40% for Nb/Mo-codoped ones. Nb/Mo-codoped $VO_2(M)$ film showed slightly enhanced thermochromic performance compared with Nb-doped $VO_2(M)$ film.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.300-304
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• 2002

We fabricated thick film monopole antennas using Mo-doped $BiNbO_{4}$ ceramics and investigated their electrical properties as a function of the Mo-doping concentration. Compared with undoped $BiNbO_{4}$ ceramics, 10 at.% Mo-doping improved microwave dielectric properties of ceramics by increased sintered density as well as decreased space charge density. Further increase in the Mo-doping concentration caused formation of $Bi_{2}MoO_{6}$ phases, resulting in deterioration of the microwave characteristics. The gain and bandwidth of the ceramic monopole antenna were also greatly affected by the Mo-doping concentration. When Mo-doping concentration was 10 at%, highest gain of ~0.7dBi with lowest bandwidth of 30% at 2.3GHz was obtained.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1327-1328
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• 2006

Lanthanum oxide was introduced to molybdenum powder by liquid-liquid doping and liquid-solid doping respectively. Mo alloys were prepared by powder metallurgy technology. The size distribution and feature of dopant particles and the fractographs of Mo alloys were investigated by TEM and SEM respectively. The results indicated that liquid-liquid doping method is favorable for refining and dispersing $La_2O_3$ particles uniformly in matrix. Fracture toughness of Mo alloys prepared by liquid-liquid doping showed better results than that of liquid-solid doping. Furthermore, the influences of the size distribution of $La_2O_3$ on properties of Mo alloys was discussed by dislocation pile-up theory.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.168-168
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• 2012

본 연구에서는 Molybdenum oxide (MoOx)-doped 4,4',4"-tris[2-naphthyl(amino)] triphenylamine(2-TNATA)의 P-doping에 의한 hole ohmic contact과 fullerene (C60)/lithium (LiF)의 electron ohmic contact에 의한 All Ohmic contact를 이용한 유기 발광 다이오드 (OLEDs)의 광저항 특성의 향상을 설명한다. 이 소자의 성능은 MoOx-doped 2-TNATA의 두께와 도핑농도에 큰 영향을 받는다. glass/ITO/MoOx-doped 2-TNATA (100 nm)/Al 구조의 소자에서 MoOx-doped 2-TNATA 도핑 농도가 25%에서 75%로 증가할수록 hole only device의 hole ohmic 특성이 향상됐다. 그 이유는 p-type doping effect 때문이다. 또한 photoemission spectra 분석결과, p-type doping effect는 hole-injecting barrier 높이는 낮추고, hole conductivity는 향상되었다. 이것은 2-TNATA에 도핑된 MoOx의 전하전송 콤플렉스의 형성으로 hole carrier의 수가 증가하여 발생되었다. MoOx-doped 2-TNATA의 hole ohmic contact과 fullerene (C60)/lithium fluoride (LiF)의 electron ohmic contact 으로 구성된 glass/ITO/MoOx-doped 2-TNATA (75%, 60 nm)/NPB (10 nm)/Alq3 (35 nm)/C60 (5 nm)/LiF (1 nm)/Al (150 nm)의 소자구조는 6,4V에서 127,600 cd/m2 최대 휘도와 약 1,000 cd/m2에서 4.7 lm/W의 높은 전력 효율을 보여준다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.2
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• pp.78-82
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• 2023

The oxygen evolution reaction (OER) is the primary challenge in renewable energy storage technologies, specifically electrochemical water splitting for hydrogen generation. We report effects of Mo doping into Ni layered double hydroxide (Ni-LDH) microcrystal on electrocatalytic activities. In this study, Mo doped Ni-LDH were grown on three-dimensional porous nicekl foam (NF) by a facile solvothermal method. Homogeneous LDH structure on the NF was clearly observed. However, the surface microstructure of the nickel foam began to be irregular and collapsed when Mo precursor is doped. Electrocatalytic OER properties were analyzed by Linear sweep voltammetry (LSV) and Electrochemical impedance spectroscopy (EIS). The amount of Mo doping used in the electrocatalytic reaction was found to play a crucial role in improving catalytic activity. The optimum Mo amount introduced into the Ni LDH was discussed with respect to their OER performance.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.535-536
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• 2013

본 연구에서는 DC/RF co-sputtering공법을 통해 제작한 In-Mo-O 투명 Mo doping 농도 및 열처리 온도에 따른 전기적, 광학적, 구조적 특성을 분석하고, 최적화된 In-Mo-O 투명전극을 유기태양전지(OPVs)와 유기발광다이오드(OLED)에 적용하여 그 가능성을 평가하였다. Mo doping 농도는 co-sputtering 공정 중 MoO3에 인가되는 radio-frequency (RF) power를 변화시켜 조절되었으며, 투명전극의 광학적 특성 및 전기적 특성 향상을 위해 성막 공정 후 급속 열처리 공정을 온도 별로 진행하였다. In-Mo-O 투명 전극은 Mo 도핑 농도에 영향을 받음을 확인할 수 있었고, 최적화된 Mo doping 파워에서 성막한 In-Mo-O 박막은 급속 열처리 공정 후 면저항 24.57 Ohm/square, 투과도 81.57% (400~1,200 nm wavelength)를 나타내었다. Bulk hetero-junction 기반의 고효율 유기태양전지와 유기발광다이오드 적용하기 위해 본 연구에서 제작된 IMO 투명전극의 구조적 특성, 결정성 및 표면특성은 x-ray diffraction (XRD), atomic force microscopy(AFM), field effect scanning electron microscopy (FE-SEM), High-resolution transmission electron microscopy (HRTEM) 분석을 통해 진행하였다. In-Mo-O 투명 전극상에 제작된 OLEDs와 OPV는 reference ITO 전극에 제작된 OLEDs/OPV와 비교할 때 유사하거나 향상된 특성을 나타내었으며 이는 In-Mo-O 박막이 OLED/OPV용 투명 전극으로 적용이 가능함을 말해준다.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.273-276
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• 2016

최근 single-layer $MoSe_2$와 같은 2차원의 TMD 화합물들이 물분해 광촉매로서 각광받고 있다. TMD 화합물 중 single-layer $MoSe_2$는 수소 발생 반응을 일으킬 수 있으나 산소 발생 반응은 일으킬 수 없어 산화 반응을 진행시킬 추가적인 전극이 필요하다. 이 연구에서는 strain과 doping을 통해 valence band를 아래로 이동시켜 $MoSe_2$를 더 좋은 물분해 광촉매로 변화시키는 방법을 모색하였다. 먼저 Armchair, zigzag, biaxial isotropic, z-axis direction으로 strain을 걸어줄 때 전자구조의 변화를 관찰하였다. z-axis 방향으로 -2.5% strain을 걸어주었을 때 VBM이 0.07eV만큼 감소하였다. 또한 Mo를 Nb로 치환하고 Se를 P, As로 치환한 다음 전자구조를 관찰하였다. Nb와 doping의 경우 VBM이 감소함을 확인하였으며 As doping의 경우 산화반응이 일어날 수 있고 산화력과 환원력이 비슷해짐을 알아내었다. 또한 산화반응과 환원반응이 일어나는 위치가 분리됨을 확인하였다.

• Korean Journal of Materials Research
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• v.19 no.8
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• pp.452-456
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• 2009

In high-efficiency Cu(In,Ga)$Se_2$ solar cells, Na is doped into a Cu(In,Ga)$Se_2$ light-absorbing layer from sodalime-glass substrate through Mo back-contact layer, resulting in an increase of device performance. However, this supply of sodium is limited when the process temperature is too low or when a substrate does not supply Na. This limitation can be overcome by supplying Na through external doping. For Na doping, an NaF interlayer was deposited on Mo/glass substrate. A Cu(In,Ga)$Se_2$ absorber layer was deposited on the NaF interlayer by a three-stage co-evaporation process As the thickness of NaF interlayer increased, smaller grain sizes were obtained. The resistivity of the NaF-doped CIGS film was of the order of $10^3{\Omega}{\cdot}cm$ indicating that doping was not very effective. However, highest conversion efficiency of 14.2% was obtained when the NaF thickness was 25 nm, suggesting that Na doping using an NaF interlayer is one of the possible methods for external doping.

• Bulletin of the Korean Chemical Society
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• v.33 no.4
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• pp.1269-1274
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• 2012

A visible light responsive N, Mo co-doped $TiO_2$ were prepared by sol-gel method. X-ray diffraction, TEM, $N_2$ adsorption, UV-vis spectroscopy, photoluminescence, and X-ray photoelectron spectroscopy were used to characterize the prepared $TiO_2$ samples. Doping restrained the phase transformation from anatase to rutile and reduced the particle sizes. The band gap was much narrowed after N, Mo co-doping. The photocatalytic activities were tested in the degradation of an aqueous solution of a reactive dyestuff, methylene blue, under visible light. The photocatalytic activities of doped $TiO_2$ were much higher than that of neat $TiO_2$. The photocatalytic stability of N, Mo co-doped $TiO_2$ was much better than that of N doped $TiO_2$.