Molybdenum doped Indium Oxide thin films prepared by rf sputtering

AbstractMolybdenum doped indium oxide (IMO) thin films rf sputtered at room temperature were studied as a function of oxygen volume percentage (O2 vol. %) varied between 0 and 17.5. The as-deposited films were amorphous irrespective of O2 vol. %. The minimum transmittance (<10 %) of the films deposited without oxygen has been increased on introducing oxygen (3.5 O2 vol. %) to a maximum of 90 %. The optical band gap has been increased from 3.80 eV (without oxygen) to 3.92 eV (3.5 O2 vol. %). The films were highly resistive and the hall coefficients were detectable only for the films deposited without oxygen. In order to increase the electrical conductivity, the films were annealed in the range 100-500°C in open-air and N2/H2 gas for 1 hour. The annealed films become polycrystalline with enhanced electrical and optical properties. The effect of annealing conditions on these films will be presented and discussed in detail.

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Some studies on Molybdenum doped Indium oxide thin films rf sputtered at room temperature

MRS Proceedings ◽

10.1557/proc-0928-gg12-03 ◽

2006 ◽

Vol 928 ◽

Cited By ~ 2

Author(s):

E. Elangovan ◽

P Barquinha ◽

A Pimental ◽

A. S. Viana ◽

R Martins ◽

...

Keyword(s):

Thin Films ◽

Absorption Coefficient ◽

Indium Oxide ◽

Room Temperature ◽

Optical Band Gap ◽

X Ray Diffraction ◽

Volume Percentage ◽

Transmittance Spectra ◽

X Ray ◽

Glass Substrates

ABSTRACTThin films of molybdenum doped indium oxide (IMO) were rf sputtered onto glass substrates at room temperature. The films were studied as a function of oxygen volume percentage (OVP) ranging 1.4 - 10.0 % in the sputtering chamber. The thickness of the films found varying between 180 and 260 nm. The X-ray diffraction pattern showed the films are polycrystalline with the peaks corresponding to (222) and (400) planes and one among them showing as a preferential orientation. It is observed that the preferred orientation changes from (222) plane to (400) as the OVP increases from 1.4 to 10.0 %. The transmittance spectra were found to be in the range of 77 to 89 %. The optical band gap calculated from the absorption coefficient of transmittance spectra was around 3.9 eV. The negative sign of Hall coefficient confirmed the films were n-type conducting. The bulk resistivity increased from 2.26 × 10−3 to 4.08 × 10−1 Ω−cm for the increase in OVP from 1.4 to 4.1 %, and thereafter increased dramatically so as the Hall coefficients were not detectable. From the AFM morphologies it is evaluated that the RMS roughness of the films ranges from 0.9 to 3.2 nm.

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Effects of the Argon Pressure on the Optical Band Gap of Zinc Oxide Thin Films Grown by Nonreactive RF Sputtering

Advances in Condensed Matter Physics ◽

10.1155/2013/970976 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 8

Author(s):

M. Acosta ◽

I. Riech ◽

E. Martín-Tovar

Keyword(s):

Thin Films ◽

Zinc Oxide ◽

Band Gap ◽

Room Temperature ◽

Optical Band Gap ◽

Rf Sputtering ◽

Argon Pressure ◽

Band Gaps ◽

Zno Thin Films ◽

Optical Band Gaps

Zinc oxide (ZnO) thin films were grown by nonreactive RF sputtering at room temperature under varying argon pressures (PAr). Their optical band gap was found to increase from 3.58 to 4.34 eV when the argon pressure increases from 2.67 to 10.66 Pa. After annealing at 200°C and 500°C, optical band gaps decrease considerably. The observed widening of the band gap with increasingPArcan be understood as being a consequence of the poorer crystallinity of films grown at higher pressures. Measurements of morphological and electrical properties of these films correlate well with this picture. Our main aim is to understand the effects ofPAron several physical properties of the films, and most importantly on its optical band gap.

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Electrical conductivity studies of mixed phthalocyanine thin films

Open Physics ◽

10.2478/bf02476501 ◽

2005 ◽

Vol 3 (1) ◽

Cited By ~ 1

Author(s):

Abraham Varghese ◽

C. Menon

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Room Temperature ◽

Optical Band Gap ◽

Thermal Evaporation ◽

Copper Phthalocyanine ◽

Thermal Evaporation Technique ◽

Nickel Phthalocyanine ◽

Mixed Films ◽

Evaporation Technique

AbstractThin films of mixed of Copper Phthalocyanine (CuPc) and Nickel Phthalocyanine (NiPc) are deposited onto a pure glass substrate by a simultaneous thermal evaporation technique at room temperature. The material D.C. electrical conductivity of films at room temperature and also films annealed at 523 K has been investigated. The optical absorption and band gaps of the films are also measured. The results show that the electrical resistance is lower for the mixed films compared with the pure samples and also the optical band gap decreases for the mixed samples compared to the pure samples.

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Effect of Different Deposition Power of In2O3Target on the Characteristics of IGZO Thin Films Using the Cosputtering Method

International Journal of Photoenergy ◽

10.1155/2014/739096 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Shang-Chao Hung ◽

Kin-Tak Lam ◽

Cheng-Fu Yang ◽

Yu-Jhen Liou

Keyword(s):

Thin Films ◽

Room Temperature ◽

Deposition Time ◽

Optical Band Gap ◽

Transparent Electrode ◽

Amorphous Structure ◽

Electrical And Optical Properties ◽

Glass Substrates ◽

Deposition Power ◽

Sputtering System

The (In, Ga, Zn)Ox(IGZO) thin films were deposited on glass substrates using cosputtering method in radio frequency magnetron sputtering system. Zn2Ga2O5(Ga2O3-2 ZnO, GZO) and In2O3ceramics were used as targets and dual guns were used to deposit the IGZO thin films. Deposition power of GZO target was 80 W and deposition power of pure In2O3target was changed from 70 W to 100 W, and the deposition time was 30 min. The effect of deposition power of In2O3target on the crystalline, surface, electrical, and optical properties of the IGZO thin films was investigated at room temperature in a pure Ar atmosphere. The cosputtered IGZO thin films showed a very smooth and featureless surface and an amorphous structure regardless of the deposition power of In2O3target due to the room temperature sputtering process. However, the cosputtered IGZO thin films exhibited transparent electrode properties because they had high transmittance ratio and low resistivity. The value variations in the optical band gap(Eg)values of the IGZO thin film were evaluated from the plots of(αhν)2=c(hν-Eg). We would also show that the deposition power of In2O3target would have a large effect on mobility andEgvalue of the IGZO thin films.

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Structural Dependence of Electrical Conductivity of thin Tellurium Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070709 ◽

1973 ◽

Vol 31 ◽

pp. 52-53

Author(s):

Mumtaz A. Dinno ◽

Manuel Schwartz ◽

Beverly Giammara

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Electrical Properties ◽

Room Temperature ◽

Extensive Study ◽

Structural Studies ◽

Nucleation Sites ◽

Electron Transport Properties ◽

Deposited Films

Capers and White made an extensive study of the growth of tellurium thin films deposited on different substrate materials but did not measure the electrical properties of the deposited films. Berryman studied the effects of film thickness, deposition rate, and substrate temperature on the electrical properties but there is no evidence that these results were correlated with structural studies. Dutton presented a method for growing large grains using a gold monolayer as nucleation sites and for these special films related electron transport properties with structure. The present study undertakes the determination of conductivity over a range of thicknesses extending from 350 Å to 2800 Å on a substrate initially at room temperature, for both annealed and nonannealed films. In addition, some work was done with quenched and heated substrates at 700 Å thickness.

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Effect of Postdeposition Annealing on the Structural, Electrical, and Optical Properties of DC Magnetron SputteredTa2O5Films

Research Letters in Materials Science ◽

10.1155/2007/95307 ◽

2007 ◽

Vol 2007 ◽

pp. 1-5 ◽

Cited By ~ 6

Author(s):

S. V. Jagadeesh Chandra ◽

P. Sreedhara Reddy ◽

G. Mohan Rao ◽

S. Uthanna

Keyword(s):

Thin Films ◽

Refractive Index ◽

Optical Properties ◽

Annealing Temperature ◽

Optical Band Gap ◽

Optical Transmittance ◽

Electrical Characteristics ◽

Electrical And Optical Properties ◽

Tantalum Target ◽

Deposited Films

Thin films of tantalum oxide were formed on quartz and silicon (111) substrates kept at room temperature (303 K) by reactive sputtering of tantalum target in the presence of mixture of oxygen and argon gases. The as-deposited films were annealed in air for an hour in the temperature range 673–873 K. The films were characterized by studying structural, dielectric, electrical, and optical properties. The as-deposited films were amorphous in nature. As the annealing temperature increased to 673 K, the films were transformed into polycrystalline. Electrical characteristics of as-deposited and annealedTa2O5thin films were compared. The thermal annealing reduced the leakage current density and increased the dielectric constant. The optical transmittance of the films increased with the increase of annealing temperature. The as-deposited films showed the optical band gap of 4.38 eV. It increased to 4.44 eV with the increase of annealing temperature to 873 K. The as-deposited films showed the low value (1.89) of refractive index and it increased to 2.15 when annealed at 873 K. The increase of refractive index with annealing temperature was due to the increase in the packing density and crystallinity of the films.

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ON THE STRUCTURE, ELECTRICAL AND OPTICAL PROPERTIES OF TiO2 SPUTTERED THIN FILMS

Surface Review and Letters ◽

10.1142/s0218625x06007871 ◽

2006 ◽

Vol 13 (01) ◽

pp. 87-92 ◽

Cited By ~ 5

Author(s):

A. ASHOUR

Keyword(s):

Thin Films ◽

Optical Constants ◽

Optical Band Gap ◽

Optical Transmittance ◽

X Ray Diffraction ◽

Electrical And Optical Properties ◽

X Ray ◽

Lattice Constants ◽

Glass Substrates ◽

Deposited Films

Titanium oxide thin films were prepared by sputtering technique onto glass substrates at room temperature (RT). The structure of the films was confirmed using X-ray diffraction (XRD) and revealed the stoichiometry with an O and Ti ratio of 2. The deposited films at RT were found to be amorphous and the films annealed at 300 and 400°C for 2 h were crystalline with orthorhombic structure. The lattice constants and grain size of the film are calculated. The electrical resistivity was found to depend on the film thickness and decreased with increasing the film thicknesses. The optical constants of the films such as the refractive index, extinction coefficient, and absorption coefficient were also determined using the optical transmittance measurements, and the results were discussed. The optical band gap varies from 3.2 to 3.5 eV as a function of oxygen/argon ratios.

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Transparent p- and n-Type Conductive Oxides With Delafossite Structure

MRS Proceedings ◽

10.1557/proc-623-235 ◽

2000 ◽

Vol 623 ◽

Cited By ~ 7

Author(s):

Hiroshi Yanagi ◽

Kazushige Ueda ◽

Shuntaro Ibuki ◽

Tomomi Hase ◽

Hideo Hosono ◽

...

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Band Gap ◽

Room Temperature ◽

Optical Band Gap ◽

Conducting Oxides ◽

Transparent Conducting ◽

Delafossite Structure ◽

P Type ◽

Type Conduction

AbstractThin films of CuAlO2, CuGaO2 and AglnO2 with delafossite structure were prepared on sapphire substrates by pulsed laser deposition method. The resulting CuA102 thin films exhibited p-type conduction and the electrical conductivity at room temperature was 0.3 Scm−1. CuGaO2 thin films were grown epitaxially on μ-Al2O3 (001) surface and showed p-type conduction (conductivity at room temperature = 0.06 S cm−1). The optical band gap was estimated to be ∼3.5 eV for CuAlO2 or ∼3.6 eV for CuGaO2. On the other hand, the thin film of Sn doped AglnO2 exhibited n-type conduction. The optical band gap and electrical conductivity at room temperature were ∼4.1 eV and 70 S cm−1, respectively. The recent work demonstrates the validity of our chemical design concept for p- and n-type transparent conducting oxides, providing an opportunity for realization of transparent p-n junction using delafossite-type oxides.

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Structure and Conductivity of Iodine-Doped C60 Thin Films

MRS Proceedings ◽

10.1557/proc-359-443 ◽

1994 ◽

Vol 359 ◽

Cited By ~ 1

Author(s):

Jun Chen ◽

Haiyan Zhang ◽

Baoqiong Chen ◽

Shaoqi Peng ◽

Ning Ke ◽

...

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Room Temperature ◽

Conductivity Measurements ◽

X Ray Diffraction ◽

Temperature Conductivity ◽

Room Temperature Conductivity ◽

X Ray ◽

Thermally Activated ◽

Order Of Magnitude

ABSTRACTWe report here the results of our study on the properties of iodine-doped C60 thin films by IR and optical absorption, X-ray diffraction, and electrical conductivity measurements. The results show that there is no apparent structural change in the iodine-doped samples at room temperature in comparison with that of the undoped films. However, in the electrical conductivity measurements, an increase of more that one order of magnitude in the room temperature conductivity has been observed in the iodine-doped samples. In addition, while the conductivity of the undoped films shows thermally activated temperature dependence, the conductivity of the iodine-doped films was found to be constant over a fairly wide temperature range (from 20°C to 70°C) exhibiting a metallic feature.

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