The Effects of the Carrier Concentrations on the Hall Mobilities of ZnO:Al Thin Films Deposited by Magnetron Sputtering

2017 ◽  
Vol 727 ◽  
pp. 938-941
Author(s):  
Xiao Jing Wang ◽  
Yun Zhang
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Magnetron Sputtering ◽  
Carrier Concentration ◽  
Carrier Mobility ◽  
Impurity Scattering ◽  
Flexible Substrates ◽  
Boundary Scattering ◽  
Scattering Mechanism ◽  
Ionized Impurity Scattering

ZnO:Al thin films were deposited on flexible substrates by magnetron sputtering. The effects of the carrier concentrations on the hall mobilities of AZO films were investigated. When the carrier concentration was high (~1020/cm3), the hall mobility decreased with increase of the carrier concentration, showing obvious characteristics of ionized impurity scattering; moreover, the carrier mobility could be expressed to be-2.14/3 proportional of the carrier concentration by combining the results of simulation and experiments.simulation and experiment. When the carrier concentration was about a magnitude of 1019 cm-3, the carrier mobility is influenced by the carrier concentration and grain size, which means the carrier mobility was affected by both the grain boundary scattering and ionized purity scattering mechanism.

Electrical Conduction Mechanism of Highly Transparent and Conductive ZnO Thin Films

2001 ◽  
Vol 666 ◽  
Author(s):  
Tadatsugu Minami ◽  
Shingo Suzuki ◽  
Toshihiro Miyata
Keyword(s):  
Electrical Conductivity ◽  
Carrier Concentration ◽  
Conduction Band ◽  
Conduction Mechanism ◽  
Impurity Scattering ◽  
Zno Thin Films ◽  
Zno Films ◽  
Boundary Scattering ◽  
Ionized Impurity Scattering ◽  
Transparent Conducting

ABSTRACTIn this paper, we describe the underlying theory along with experiments concerning the electrical conductivity of transparent conducting ZnO films with a carrier concentration of 1019-1021 cm−3. The experimentally determined mobility as a function of carrier concentration in the range of 1019-1021 cm−3 could be quantitatively referenced to a theoretically calculated mobility that is dominated by not only grain boundary scattering but also ionized impurity scattering using the Brooks-Herring-Dingle theory with both degeneracy and nonparabolicity of the conduction band taken into account. Concerning nonparabolicity, the conduction band effective mass as a function of carrier concentration was theoretically analyzed and experimentally determined.

Thermoelectric properties of PbTe thin films prepared by gas evaporation method

1999 ◽  
Vol 14 (1) ◽  
pp. 209-212 ◽  
Author(s):  
Masatoshi Ito ◽  
Won-Son Seo ◽  
Kunihito Koumoto
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Grain Size ◽  
Seebeck Coefficient ◽  
Grain Boundaries ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Carrier Mobility ◽  
Evaporation Method

PbTe thin films with fine grains were successfully fabricated by the gas evaporation method. Thermoelectric properties, i.e., Seebeck coefficient and electrical conductivity, both decreased with decreasing grain size. This was attributed to the decrease in carrier mobility exceeding the increase in carrier concentration with decreasing grain size. It was clarified that the effects of grain boundaries and of oxidation on carrier mobility are considerably large.

scholarly journals Manipulation of ionized impurity scattering for achieving high thermoelectric performance in n-type Mg3Sb2-based materials

2017 ◽  
Vol 114 (40) ◽  
pp. 10548-10553 ◽  
Author(s):  
Jun Mao ◽  
Jing Shuai ◽  
Shaowei Song ◽  
Yixuan Wu ◽  
Rebecca Dally ◽  
...  
Keyword(s):  
Power Factor ◽  
Carrier Mobility ◽  
Phonon Scattering ◽  
Impurity Scattering ◽  
Substantial Improvement ◽  
Thermoelectric Performance ◽  
Scattering Mechanism ◽  
Carrier Scattering ◽  
Ionized Impurity Scattering ◽  
Higher Carrier Mobility

Achieving higher carrier mobility plays a pivotal role for obtaining potentially high thermoelectric performance. In principle, the carrier mobility is governed by the band structure as well as by the carrier scattering mechanism. Here, we demonstrate that by manipulating the carrier scattering mechanism in n-type Mg3Sb2-based materials, a substantial improvement in carrier mobility, and hence the power factor, can be achieved. In this work, Fe, Co, Hf, and Ta are doped on the Mg site of Mg3.2Sb1.5Bi0.49Te0.01, where the ionized impurity scattering crosses over to mixed ionized impurity and acoustic phonon scattering. A significant improvement in Hall mobility from ∼16 to ∼81 cm2⋅V−1⋅s−1 is obtained, thus leading to a notably enhanced power factor of ∼13 μW⋅cm−1⋅K−2 from ∼5 μW⋅cm−1⋅K−2. A simultaneous reduction in thermal conductivity is also achieved. Collectively, a figure of merit (ZT) of ∼1.7 is obtained at 773 K in Mg3.1Co0.1Sb1.5Bi0.49Te0.01. The concept of manipulating the carrier scattering mechanism to improve the mobility should also be applicable to other material systems.

Effects of Continuous and Discontinuous Deposition Time in Reactive Direct Current Magnetron Sputtering of Titanium Dioxide Thin Films

2015 ◽  
Vol 1131 ◽  
pp. 251-254
Author(s):  
Montri Aiempanakit ◽  
Chantana Salawan ◽  
Kamon Aiempanakit
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Surface Morphology ◽  
Magnetron Sputtering ◽  
Direct Current ◽  
Deposition Time ◽  
Spherical Shape ◽  
Contact Angles ◽  
Water Contact ◽  
Direct Current Magnetron Sputtering

The effect of continuous and discontinuous deposition time on the properties of TiO2 thin films deposited by reactive direct current magnetron sputtering (DCMS) on glass substrates was investigated. The deposition processes were designed for a condition of continuous deposition time D1 (60 min) and three conditions of discontinuous deposition time D2 (30 min × 2 times), D3 (15 min × 4 times), and D4 (1 min × 60 times). The crystal structure, surface morphology, and hydrophilicity of TiO2 thin films were characterized by X-ray diffraction, atomic force microscope, and water contact angle method, respectively. It was found that the increasing of discontinuous deposition time (conditions from D1 to D4) shows the changing of grain size from big grain size with spherical shape to small grain size with oval shape. The crystallinity of TiO2 films decrease with increasing the discontinuous deposition time. The water contact angles also decrease as a function of increasing discontinuous deposition time. These results may be explained from the accumulation of heat on the substrate which affected the phase composition and surface morphology of TiO2 thin films.

Structural, Morphological and Adhesion Properties of Cofeb Thin Films Deposited by DC Magnetron Sputtering

2013 ◽  
Vol 802 ◽  
pp. 47-52
Author(s):  
Chuleerat Ibuki ◽  
Rachasak Sakdanuphab
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Magnetron Sputtering ◽  
Crystalline Structure ◽  
Glass Substrate ◽  
Intrinsic Stress ◽  
Dc Magnetron Sputtering ◽  
Adhesion Properties ◽  
Sputtering Power

In this work the effects of amorphous (glass) and crystalline (Si) substrates on the structural, morphological and adhesion properties of CoFeB thin film deposited by DC Magnetron sputtering were investigated. It was found that the structure of a substrate affects to crystal formation, surface morphology and adhesion of CoFeB thin films. The X-Ray diffraction patterns reveal that as-deposited CoFeB thin film at low sputtering power was amorphous and would become crystal when the power increased. The increase in crystalline structure of CoFeB thin film is attributed to the crystalline substrate and the increase of kinetic energy of sputtering atoms. Atomic Force Microscopy images of CoFeB thin film clearly show that the roughness, grain size, and uniformity correlate to the sputtering power and the structure of substrate. The CoFeB thin film on glass substrate shows a smooth surface and a small grain size whereas the CoFeB thin film on Si substrate shows a rough surface and a slightly increases of grain size. Sticky Tape Test on CoFeB thin film deposited on glass substrate indicates the adhesion failure with a high sputtering power. The results suggest that the crystalline structure of substrate affects to the atomic bonding and the sputtering power affects to intrinsic stress of CoFeB thin film.

RF Magnetron Sputtering Processed Transparent Conductive Aluminum Doped ZnO thin Films with Excellent Optical and Electrical Properties

2021 ◽  
Author(s):  
Chunhu Zhao ◽  
Junfeng Liu ◽  
Yixin Guo ◽  
Yanlin Pan ◽  
Xiaobo Hu ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Magnetron Sputtering ◽  
Carrier Concentration ◽  
Rf Magnetron Sputtering ◽  
Zno Thin Films ◽  
Band Model ◽  
Deposition Condition ◽  
Optical And Electrical Properties ◽  
Doped Zno

Abstract Aluminum doped ZnO thin films (AZO), which simultaneously transmit light and conduct electrical current, are widely applied in photovoltaic devices. To achieve high performance AZO thin films, the effects of RF magnetron sputtering conditions on the optical and electrical properties of the films has been explored. The optimized AZO thin films exhibit strong (002) orientated growth with hexagonal wurtzite structure. The minimum resistivity of 0.9Í10-3 Ω·cm, the highest carrier concentration of 2.8Í1020 cm-3, the best Hall mobility of 22.8 cm2·(V·s)-1 and average transmittance above 85% can be achieved at the optimum deposition condition of 0.2 Pa, 120 W and 200 °C. Considering the single parabolic band model, the bandgap shift by carrier concentration of the films can be attributed to the Burstein-Moss effect. The results indicate that RF magnetron sputtered AZO thin films are promising for solar cell applications relying on front contact layers.

scholarly journals Effect of rapid thermal annealing on structural and optical properties of ZnS thin films fabricated by RF magnetron sputtering technique

2019 ◽  
Vol 14 (1) ◽  
pp. 53-63 ◽  
Author(s):  
M. S. Bashar ◽  
Rummana Matin ◽  
Munira Sultana ◽  
Ayesha Siddika ◽  
M. Rahaman ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Carrier Concentration ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Annealing Temperature ◽  
Annealing Treatment ◽  
Localized States ◽  
Stoichiometric Ratio ◽  
Deposited Films

AbstractThe ZnS thin films have been deposited by radio frequency magnetron sputtering at room temperature. Post-deposition rapid thermal annealing treatment was done for the films deposited at different powers ranging from 70 to 100 W. One peak is observed for as-deposited and annealed thin films at around 28.48° corresponding to the (111) reflection plane indicating a zincblende structure. The overall intensity of the peaks and the FWHM values of as-deposited films increased after annealing corresponding to the increase in crystallinity. The optical energy bandgap is found in the range of 3.24–3.32 eV. With increasing annealing temperature, the decrease in the Urbach energy values indicating a decrease in localized states which is in good agreement with the XRD results where the crystallinity increased. The surface morphology of the films seems to be composed of Nano-granules with a compact arrangement. Apparently, the grain size increases in the deposited films as annealing temperature increases. The compositional ratio attained close to the stoichiometric ratio of 1:1 after annealing. From the Hall effect measurement, the carrier concentration and mobility are found to increase after annealing. The high carrier concentration and mobility also comply with structural and optical analysis. Best results are found for the film annealed at 400 °C deposited at 90 W.

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