• Title/Summary/Keyword: MoS$_2$ electrode

Search Result 47, Processing Time 0.026 seconds

The Charge-Discharge Performance of $Li/MoS_2$ Battery with liquid Electrolyte of Tetra(ethylene glycol] Dimethyl Ether[TEGDME] (TEGDME 액체 전해질을 사용한 $Li/MoS_2$ 전지의 충.방전 특성)

  • Kwon, Jeong-Hui;Ryu, Ho-Suk;Kim, Ki-Won;Ahn, Jou-Hyeon;Jeong, Yong-Su;Lee, Kun-Hwan;Ahn, Hyo-Jun
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.20 no.3
    • /
    • pp.238-244
    • /
    • 2009
  • We investigated the electrochemical properties of lithium/molybdenum sulfide(Li/MoS$_2$) using tetra (ethylene glycol) dimethyl ether(TEGDME) electrolyte. The Li/TEGDME/MoS$_2$ cell showed the first discharge capacity of 288mAhg$^{-1}$. From the XRD, SEM results of the MOS$_2$ electrode in various cut-off voltage during charge-discharge process, MoS$_2$ partly changed into Li$_2$S and Mo during discharge and Li$_2$S partly recovered into MOS$_2$ and Li during charge. Full charged MOS$_2$ electrode showed lump shape of big size, which might be related to agglomerate of MoS$_2$ particles. Therefore, the degradation might be related to decrease of active material for electrochemical reaction by agglomeration of MOS$_2$.

Electrochemical Stability of Co-Mo and Ni-Mo Intermetallic Compound Electrodes for Hydrogen Electrode of Alkaline Fuel Cell (알칼리형 연료전지의 수소극용 Co-Mo 및 Ni-Mo 금속간화합물 전극의 전기화학적 안정성)

  • Lee C. R.;Kang S. G.
    • Journal of the Korean Electrochemical Society
    • /
    • v.2 no.3
    • /
    • pp.150-155
    • /
    • 1999
  • The Electrochemical stabilities of the Brewer-Engel type intermetallic compounds of Co-Mo $(35 wt\%)$ and Ni-Mo$(35 wt\%)$ manufactured by the arc-melting method for the hydrogen electrode of $H_2-O_2$ alkaline fuel cell were investigated. Effects of temperature and concentration on the electrochemical behavior of the electrodes in the $80^{\circ}C$ 6 N KOH solution deaerated with $N_2$ gas were studied by electrochemical methods. The effect of overpotential on the electrochemical stabilities of Co-Mo and Ni-Mo intermetallic compounds was also discussed under the normal operation condition of AFC. It was shown that Co-Mo electrode had lower electrochemical stability as compared to Ni-Mo. In the case of Co-Mo electrode, a simultaneous dissolution of cobalt and molybdenum has occurred at low anodic overpotential form equilibrium hydrogen electrode potential, but the dissolution of cobalt was serious, and Co(OH)l layer on the electrode surface formed at the high anodic overpotential. In contrast the Ni-Mo electrode had high electrochemical stability because formation of the dense and thin protective $Ni(OH)_2$ layer prevented the dissolution of molybdenum.

Effect of gate electrode material on electrical characteristics of a-IGZO thin-film transistors (게이트 전극 물질이 a-IGZO 박막트랜지스터의 전기적 특성에 미치는 영향)

  • Oh, Hyungon;Cho, Kyoungah;Kim, Sangsig
    • Journal of IKEEE
    • /
    • v.21 no.2
    • /
    • pp.170-173
    • /
    • 2017
  • In this study, we fabricate amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) with three different gate electrode materials of Al, Mo and Pt on plastic substrates and investigate their electrical characteristics. Compared to an a-IGZO TFT with Al gate electrode, the threshold voltage of an a-IGZO TFT with a Pt electrode decreases from -4.2 to -0.3 V. and the filed-effect mobility is improved from 15.8 to $22.1cm^2/V{\cdot}s$. The threshold voltage shift of the TFT is affected by the difference between the work function of the gate electrode and the Fermi energy of the channel layer. Moreover, the Pt gate electrode is considered to be the suitable material in terms of the electrical characteristics of the TFT. In addition, an description on an a-IGZO TFT with a Mo electrode will be given here.

Direct Electrochemistry and Electrocatalysis of Myoglobin with CoMoO4 Nanorods Modified Carbon Ionic Liquid Electrode

  • Zhao, Zengying;Cao, Lili;Hu, Anhui;Zhang, Weili;Ju, Xiaomei;Zhang, Yuanyuan;Sun, Wei
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.2
    • /
    • pp.475-481
    • /
    • 2013
  • By using ionic liquid 1-hexylpyridinium hexafluorophosphate ($HPPF_6$) based carbon ionic liquid electrode (CILE) as the substrate electrode, a $CoMoO_4$ nanorods and myoglobin (Mb) composite was casted on the surface of CILE with chitosan (CTS) as the film forming material to obtain the modified electrode (CTS/$CoMoO_4$-Mb/CILE). Spectroscopic results indicated that Mb retained its native structures without any conformational changes after mixed with $CoMoO_4$ nanorods and CTS. Electrochemical behaviors of Mb on the electrode were carefully investigated by cyclic voltammetry with a pair of well-defined redox peaks from the heme Fe(III)/Fe(II) redox center of Mb appeared, which indicated that direct electron transfer between Mb and CILE was realized. Electrochemical parameters such as the electron transfer number (n), charge transfer coefficient (${\alpha}$) and electron transfer rate constant ($k_s$) were estimated by cyclic voltammetry with the results as 1.09, 0.53 and 1.16 $s^{-1}$, respectively. The Mb modified electrode showed good electrocatalytic ability toward the reduction of trichloroacetic acid in the concentration range from 0.1 to 32.0 mmol $L^{-1}$ with the detection limit as 0.036 mmol $L^{-1}$ ($3{\sigma}$), and the reduction of $H_2O_2$ in the concentration range from 0.12 to 397.0 ${\mu}mol\;L^{-1}$ with the detection limit as 0.0426 ${\mu}mol\;L^{-1}$ ($3{\sigma}$).

Optoelectric properties of gate-tunable n-MoS2/n-WSe2 heterojunction with proper electrode metals

  • Lee, Seom-Gyun;Park, Min-Ji;Yu, Gyeong-Hwa
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.332.2-332.2
    • /
    • 2016
  • Two dimensional transition-metal dichalcogenides (TMDs) semiconductors are attractive materials for optoelectric devices because of their direct energy bandgap and transparency. To investigate the feasibility of transparent p-n junctions, we have fabricated a p-n heterojunction consisting of p-type WSe2 and n-type MoS2 flakes since WSe2 and MoS2 with proper electrode metals exhibit p-type and n-type behaviors, respectively. These heterojunctions exhibits gate-tunable rectifying behaviors and photovoltaic effects (ECE ~ 0.2%) indicating that p-n junctions were formed. In addition, photocurrent and photovoltaic effects were observed under light illumination, which were dependent on the gate voltage. In addition, the photocurrent mapping images indicate that the photovoltaic effects comes from the junction area. Possible origins of gate-tunability are discussed.

  • PDF

A Study of Mo Back Electrode for CIGSe2 Thin Film Solar Cell (CIGSe2 박막태양전지용 Mo 하부전극의 물리·전기적 특성 연구)

  • Choi, Seung-Hoon;Park, Joong-Jin;Yun, Jeong-Oh;Hong, Young-Ho;Kim, In-Soo
    • Journal of the Korean Vacuum Society
    • /
    • v.21 no.3
    • /
    • pp.142-150
    • /
    • 2012
  • In this Study, Mo back electrode were deposited as the functions of various working pressure, deposition time and plasma per-treatment on sodalime glass (SLG) for application to CIGS thin film solar cell using by DC sputtering method, and were analyzed Mo change to $MoSe_2$ layer through selenization processes. And finally Mo back electrode characteristics were evaluated as application to CIGS device after Al/AZO/ZnO/CdS/CIGS/Mo/SLG fabrication. Mo films fabricated as a function of the working pressure from 1.3 to 4.9mTorr are that physical thickness changed to increase from 1.24 to 1.27 ${\mu}m$ and electrical characteristics of sheet resistance changed to increase from 0.195 to 0.242 ${\Omega}/sq$ as according to the higher working pressure. We could find out that Mo film have more dense in lower working pressure because positive Ar ions have higher energy in lower pressure when ions impact to Mo target, and have dominated (100) columnar structure without working pressure. Also Mo films fabricated as a function of the deposition time are that physical thickness changed to increase from 0.15 to 1.24 ${\mu}m$ and electrical characteristics of sheet resistance changed to decrease from 2.75 to 0.195 ${\Omega}/sq$ as according to the increasing of deposition time. This is reasonable because more thick metal film have better electrical characteristics. We investigated Mo change to $MoSe_2$ layer through selenization processes after Se/Mo/SLG fabrication as a function of the selenization time from 5 to 40 minutes. $MoSe_2$ thickness were changed to increase as according to the increasing of selenization time. We could find out that we have to control $MoSe_2$ thickness to get ohmic contact characteristics as controlling of proper selenization time. And we fabricated and evaluated CIGS thin film solar cell device as Al/AZO/ZnO/CdS/CIGS/Mo/SLG structures depend on Mo thickness 1.2 ${\mu}m$ and 0.6 ${\mu}m$. The efficiency of CIGS device with 0.6 ${\mu}m$ Mo thickness is batter as 9.46% because Na ion of SLG can move to CIGS layer more faster through thin Mo layer. The adhesion characteristics of Mo back electrode on SLG were improved better as plasma pre-treatment on SLG substrate before Mo deposition. And we could expect better efficiency of CIGS thin film solar cell as controlling of Mo thickness and $MoSe_2$ thickness depend on Na effect and selenization time.

Magneto-transport properties of CVD grown MoS2 lateral spin valves

  • Jeon, Byeong-Seon;Lee, Sang-Seon;Hwang, Chan-Yong
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.336-336
    • /
    • 2016
  • We have investigated magneto-transport properties in a MoS2 lateral spin-valve structures for different ferromagnetic CoFe electrode shapes and MoS2 channel lengths. For these devices, high quality and large-scale MoS2 thin films were synthesized through sulfurization of epitaxial MoO3 films and these sulfurized-MoO3 thin films properties are in good agreements with measurements on exfoliated MoS2 film. Magneto-transport measurements show a clear rectangular magnetoresistance signal of 0.16% and a spin polarization of 0.00012%. By using the one-dimensional spin diffusion equation, we extracted the spin diffusion length and coefficient, finding them to be 12 nm and $1.44{\times}10-3cm2/s$, respectively. These small values of magnetoresistance and spin polarization could be enhanced by appeasement of conductivity mismatch between the ferromagnet and semiconductor interface.

  • PDF

Properties, Preparation, and Energy Storage Applications of Two-dimensional Molybdenum Disulfide (2차원 이황화몰리브덴의 성질, 제조 및 에너지 저장 소자 응용)

  • Choi, Bong Gill
    • Applied Chemistry for Engineering
    • /
    • v.30 no.2
    • /
    • pp.133-140
    • /
    • 2019
  • Two-dimensional (2D) ultrathin molybdenum dichalcogenides $MoS_2$ has gained a great deal of attention in energy conversion and storage applications because of its unique morphology and property. The 2D $MoS_2$ nanosheets provide a high specific surface area, 2D charge channel, sub-nanometer thickness, and high conductivity, which lead to high electrochemical performances for energy storage devices. In this paper, an overview of properties and synthetic methods of $MoS_2$ nanosheets for applications of supercapacitors and rechargeable batteries is introduced. Different phases triangle prismatic 2H and metallic octahedral 1T structured $MoS_2$ were characterized using various analytical techniques. Preparation methods were focused on top-down and bottom-up approaches, including mechanical exfoliation, chemical intercalation and exfoliation, liquid phase exfoliation by the direct sonication, electrochemical intercalation exfoliation, microwave-assisted exfoliation, mechanical ball-milling, and hydrothermal synthesis. In addition, recent applications of supercapacitors and rechargeable batteries using $MoS_2$ electrode materials are discussed.

Characteristics of Sputtering Mo Doped Carbon Films and the Application as the Gate Electrode in Organic Thin Film Transistor (스퍼터링 Mo 도핑 탄소박막의 특성과 유기박막트랜지스터의 게이트 전극으로 응용)

  • Kim, Young Gon;Park, Yong Seob
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.30 no.1
    • /
    • pp.23-26
    • /
    • 2017
  • Mo doped carbon (C:Mo) thin films were fabricated with various Mo target power densities by unbalanced magnetron sputtering (UBM). The effects of target power density on the surface, structural, and electrical properties of C:Mo films were investigated. UBM sputtered C:Mo thin films exhibited smooth and uniform surfaces. However, the rms surface roughness of C:Mo films were increased with the increase of target power density. Also, the resistivity value of C:Mo film as electrical properties was decreased with the increase of target power density. From the performance of organic thin filml transistor using conductive C:Mo gate electrode, the carrier mobility, threshold voltage, and on/off ratio of drain current (Ion/Ioff) showed $0.16cm^2/V{\cdot}s$, -6.0 V, and $7.7{\times}10^4$, respectively.

Characteristics of Carbon-Doped Mo Thin Films for the Application in Organic Thin Film Transistor (유기박막트랜지스터 응용을 위한 탄소가 도핑된 몰리브덴 박막의 특성)

  • Dong Hyun Kim;Yong Seob Park
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.36 no.6
    • /
    • pp.588-593
    • /
    • 2023
  • The advantage of OTFT technology is that large-area circuits can be manufactured on flexible substrates using a low-cost solution process such as inkjet printing. Compared to silicon-based inorganic semiconductor processes, the process temperature is lower and the process time is shorter, so it can be widely applied to fields that do not require high electron mobility. Materials that have utility as electrode materials include carbon that can be solution-processed, transparent carbon thin films, and metallic nanoparticles, etc. are being studied. Recently, a technology has been developed to facilitate charge injection by coating the surface of the Al electrode with solution-processable titanium oxide (TiOx), which can greatly improve the performance of OTFT. In order to commercialize OTFT technology, an appropriate method is to use a complementary circuit with excellent reliability and stability. For this, insulators and channel semiconductors using organic materials must have stability in the air. In this study, carbon-doped Mo (MoC) thin films were fabricated with different graphite target power densities via unbalanced magnetron sputtering (UBM). The influence of graphite target power density on the structural, surface area, physical, and electrical properties of MoC films was investigated. MoC thin films deposited by the unbalanced magnetron sputtering method exhibited a smooth and uniform surface. However, as the graphite target power density increased, the rms surface roughness of the MoC film increased, and the hardness and elastic modulus of the MoC thin film increased. Additionally, as the graphite target power density increased, the resistivity value of the MoC film increased. In the performance of an organic thin film transistor using a MoC gate electrode, the carrier mobility, threshold voltage, and drain current on/off ratio (Ion/Ioff) showed 0.15 cm2/V·s, -5.6 V, and 7.5×104, respectively.