• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.13 no.1
• /
• pp.6-12
• /
• 2000

In this study, molybdenum thin films were etched with Cl\ulcorner/(Cl\ulcorner+SF\ulcorner) gas mixing ratio in an magneti-cally enhanced reactive ion etching(MERIE) by the etching parameters such as rf power of 250 watts, chamber pressure of 100 mTorr and B-field of 30 gauss. The etch rate was 150nm/min under Cl\ulcorner/(Cl\ulcorner+SF\ulcorner) gas mixing ratio of 0.25. At this time, the selectivity of Mo to SiO\ulcorner, photoresist were respectively 0.94, 0.05. The surface reaction of the etched Mo thin films was investigated with X-ray photoelectron spectroscopy(XPS). It was analyzed that Mo peaks was mainly observed in Mo-O bonds formed MoO\ulcorner compounds and F was detected in Mo-F and O-F bonds. Cl peaks were detected by the peak of Cl 2p\ulcorner in Cl-Mo bonds of MoCl\ulcorner or MoO\ulcornerCl\ulcorner formulas. Almost all of both Cl and S atoms had been com-bined with Mo, respectively.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2012.11a
• /
• pp.103-104
• /
• 2012

고상반응법을 사용하여 $Eu^{3+}$ 이온의 농도를 변화시키면서 $Ba_{1-x}MoO_4:Eu{_x}^{3+}$ 형광체 분말을 제조하였다. 합성한 적색 형광체의 결정 구조, 표면 형상, 발광 및 흡수 스펙트럼은 각각 XRD, SEM, 자외선-가시광선 분광기를 사용하여 조사하였다. 형광체 분말의 결정 구조는 $Eu^{3+}$ 이온의 농도비에 관계없이 $2{\theta}=26.52^{\circ}$에 주 피크를 갖는 정방정계이었으며, 최대 적색 발광 스펙트럼은 618 nm에서 관측되었다.

• Journal of the Korean Society of Safety
• /
• v.3 no.1
• /
• pp.7-13
• /
• 1988

The oxides in perovskite type, $LaMO_3$ (M=Ni, Cr, Fe, Co), compared with gas sensors which have been used, were synthesised and then examined sensor response comparatively in order to make a thick film gas sensor having a good gas selectivity, durability and simple manufacturing. The oxides in perovskite type, $LaFe_{1-x}O_3$ (x=0.2, 0.4, 0.6, 0.8), which a part of Fe was replaced with Co, were examined with regard to their electric resistance with variable temperature and sensor response for carbon monoxide gas.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.4
• /
• pp.1269-1274
• /
• 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 $TiO_2$.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.449-449
• /
• 2010

유기발광소자(organic light-emitting diodes, OLEDs)는 저공정비용, 경량화, 가용성 및 대면적화 등의 장점으로 조명 분야와 디스플레이 분야로의 응용 가능성으로 인해 크게 주목을 받아 왔다. 이러한 OLED 소자의 고효율, 고휘도 및 저소비전력 등을 구현하기 위해서는 전극으로부터 전하 주입 층으로 효율적인 전하 주입이 요구된다. 즉, 각 전극의 폐르미 준위로부터 전하 전도준위대로의 전하주입 장벽이 없어야 한다. 본 연구에서는 홀 주입장벽이 없는 정공주입 층으로 $MoO_x$(molybdenum oxide)가 도핑된 NPB(N, N'-diphenyl-N, N'-bis(1-naphthyl)-1,1'-biphenyl-4,4'-diamine) 층을 사용하여 hole-only 소자를 제작하고 전류-전압 특성을 통해 양극으로부터 홀주입 층으로의 hole-ohmic 특성을 고찰했다. 또한, 전자 주입장벽이 없는 전자주입 층으로 $C_{60}$(fullerene)/LiF(lithum fluoride)의 이종 층을 사용하여 electron-only 소자를 제작하고 음극으로부터 전자주입 층으로의 전자 ohmic 특성을 조사했다. 또한, 전극으로부터 전하주입 층으로 ohmic 특성을 더 자세히 이해하기 위하여 전하주입 층의 자외선 광방출 스펙트럼(ultraviolet photoemission spectra)을 조사했다. 한편, glass/ITO/$MoO_x$-doped NPB (x%: x=0,25, 50 및 75; 5nm)/NPB (63nm)/$Alq_3$ (37nm)/$C_{60}$ (5nm)/LiF (1nm)/Al (100nm)로 구성된 all-ohmic OLED 소자의 발광특성은 $MoO_x$의 도핑 농도가 25%이상일 때 최적의 특성을 보여줬다. 이러한 현상은 정공주입 층에서 p형 도핑 농도의 증가에 따른 정공 농도의 증가에 기인한다. 또한 $MoO_x$의 도핑 농도의 증가에 따라 정공주입 층의 new gap state와 전극의 페르미 준위의 pinning에 기인한다. 25%의 $MoO_x$을 가진 OLED소자는 7.2V의 낮은 전압에서 $58300 cd/m^2$의 높은 휘도를 보여줬다.

• Journal of the Korean Chemical Society
• /
• v.18 no.4
• /
• pp.267-271
• /
• 1974

The tetradentate schiff base, N,N'-bis(salicylaldehyde)-ethylene diimine has been reacted with a series of Mo(IV), Mo(V), Mo(IV), and Mo(III) oxidation states to form new Complexes; $[MoO_2(C_{16}H_{14}O_2N_2)], (MoO(C_{16}H_{14}O_2N_2)]_2O, (Mo(SCN)(C_{16}H_{14}O_2N_2)]_2O, and (Mo(H_2O)(C_{16}H_{14}O_2N_2)]_2O.$ These complexes have hexa coordinated configurations and the mole ratio of these ions to the ligand was 1:1. These complexes have been identified by visible spectra, infrared specra, T.G.A., D.T.A., and elemental analysis.

• Korean Journal of Materials Research
• /
• v.29 no.5
• /
• pp.322-327
• /
• 2019

Hole carrier selective MoOx film is obtained by atomic layer deposition(ALD) using molybdenum hexacarbonyl[$Mo(CO)_6$] as precursor and ozone($O_3$) oxidant. The growth rate is about 0.036 nm/cycle at 200 g/Nm of ozone concentration and the thickness of interfacial oxide is about 2 nm. The measured band gap and work function of the MoOx film grown by ALD are 3.25 eV and 8 eV, respectively. X-ray photoelectron spectroscopy(XPS) result shows that the $Mo^{6+}$ state is dominant in the MoOx thin film. In the case of ALD-MoOx grown on Si wafer, the ozone concentration does not affect the passivation performance in the as-deposited state. But, the implied open-circuit voltage increases from $576^{\circ}C$ to $620^{\circ}C$ at 250 g/Nm after post-deposition annealing at $350^{\circ}C$ in a forming gas ambient. Instead of using a p-type amorphous silicon layer, high work function MoOx films as hole selective contact are applied for heterojunction silicon solar cells and the best efficiency yet recorded (21 %) is obtained.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.5 no.6
• /
• pp.558-561
• /
• 2004

The morphology of silica supported $MoO_{3}$ catalysts, which was prepared by impregnation of ammonium heptamolybdate(AHM) with various surface loadings up to 4 atoms $Mo/nm^{2}$, was studied using x-ray diffraction(XRD). All morphologies of silica supported $MoO_{3}$ appear to be thermodynamically driven. For high loaded catalysts there appeared three states: a sintered and well-dispersed hexagonal state at moderate temperature calcination($300^{\circ}C$), and a sintered orthorhombic state at high temperature calcination($500^{\circ}C$). Whereas the sintered orthorhombic phase is detected by XRD at loadings in excess of 1.1 atom $Mo/nm^{2}$, the well-dispersed hexagonal phase is not detected even until 4.0 $atomsMo/nm^{2}$. The higher apparent dispersion of the hexagonal phase may arise from some role of ammonia which results in a stronger $MoO_{3}-SiO_{2}$ surface interaction.

• Tribology and Lubricants
• /
• v.15 no.2
• /
• pp.184-192
• /
• 1999

Various compositions of$ Cr_2$$O_3$/Mo composite powders were fabricated using spray-drying method and plasma-spray coatings of these powders were prepared to understand their tribological properties. Experiments were conducted using a reciprocal type tribo-tester at room temperature under dry sliding condition. The worn surface of coated specimens were observed using SEM (Scanning Electron Microscopy) and chemical compositions were analyzed using XRD (X-ray Diffractometry) and XPS (X-ray Photoelectron Spectroscopy). The results showed that friction coefficient of the Mo added specimens were lower than that of $Cr_2$$O_3$specimen. However $Cr_2$$O_3$specimen showed the lowest wear loss. Wear protecting layer were observed at the worn surface of coated specimens with Mo addition. From the XPS analysis, the mixed phases of $Cr_2$$O_3$ $CrO_3$and $MoO_3$were founded in the wear protecting layer.

• Bulletin of the Korean Chemical Society
• /
• v.10 no.1
• /
• pp.8-12
• /
• 1989

The polycrystalline powder of (BaLa)(MgMo)$O_6$ has been prepared at $1350^{\circ}C$ in a nitrogen flowing atmosphere. The powder X-ray diffraction pattern indicates that (BaLa)(MgMo)$O_6$ has a cubic perovskite structure ($a_0$ = 8.019(3) $\AA)$ with 1:1 ordering or $Mg^{2+}$ and $Mo^{5+}$ in the oxide lattice. The infrared spectrum shows two strong absorption bands with their maxima at 600(${\nu}3$) and 365(${\nu}4$) cm-1, which are attributed to $2T_{1U}$, modes of molybdenum octahedra MoO6 in the crystal lattice. According to the magnetic susceptibility measurement, the compound shows a paramagnetic behavior which follows the Curie-Weiss law below room temperature with the effective magnetic moment 1.60(1){$\mu}B$, which is consistent with that of spin only value ($1.73{\mu}B$) for $Mo^{5+}$ ($4d^1$ electronic configuration). From the thermogravimetric and X-ray diffraction analyses, it has been found that (BaLa)(MgMo)$O_6$ decomposes gradually into $BaMoO_4$, $MoO_3$ and unidentified phases above $900^{\circ}C$ in an ambient atmosphere, absorbing about 0.25 mole $O_2$ per mole of Mo ion, which also supports that oxidation state of $Mo^{5+}$ in the (BaLa)(MgMo)$O_6$.