Predominant Scattering Mechanism in Transparent Conductive Oxide Films

2001 ◽  
Vol 666 ◽  
Author(s):  
Chen Meng ◽  
Pei Zhiliang ◽  
Wang Xi ◽  
Sun Cao ◽  
Wen Lishi
Keyword(s):  
Effective Mass ◽  
Carrier Concentration ◽  
Lower Limit ◽  
Strong Dependence ◽  
Impurity Scattering ◽  
Transparent Conductive Oxide ◽  
Potential Scattering ◽  
Scattering Mechanism ◽  
Upper Limit ◽  
Ion Impurity

ABSTRACTContributions of acoustical deformation scattering, ion impurity scattering and grain boundary potential scattering to the conductivity of TCO films have been calculated to discuss the predominant scattering mechanism, regardless of precise details of the preparation procedure. The results indicate that the effective mass of charge carriers has a strong dependence on carrier concentration. Based on the effective mass correction, as well as the carrier concentration-ionized impurity centers correction, scattering due to ion impurity has been developed to explain the upper limit of mobility or the lower limit of resistivity of TCO films. Two empirical expressions are introduced to depict the dependence of the upper limit of mobility and the lower limit of resistivity of TCO films on carrier concentration.

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.

Density-of-States Effective Mass and Scattering Parameter Measurements on Transparent Conducting Oxides Using Second-Order Transport Phenomena

2000 ◽  
Vol 623 ◽  
Author(s):  
D. L. Young ◽  
T. J. Coutts ◽  
X. Li ◽  
J. Keane ◽  
V. I. Kaydanov ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Effective Mass ◽  
Density Of States ◽  
Transport Theory ◽  
Transparent Conducting Oxides ◽  
Impurity Scattering ◽  
Scattering Mechanism ◽  
Scattering Parameter ◽  
Conducting Oxides ◽  
Transparent Conducting

AbstractTransparent conducting oxides (TCO) have relatively low mobilities, which limit their performance optically and electrically, and which limit the techniques that may be used to explore their band structure via the effective mass. We have used transport theory to directly measure the density-of-states effective mass and other fundamental electronic properties of TCO films. The Boltzmann transport equation may be solved to give analytic solutions to the resistivity, Hall, Seebeck, and Nernst coefficients. In turn, these may be solved simultaneously to give the density-of-states effective mass, the Fermi energy relative to either the conduction or valence band, and a scattering parameter, s, which characterizes the relaxation time dependence on the carrier energy and can serve as a signature of the dominate scattering mechanism. The little-known Nernst effect is essential for determining the scattering parameter and, thereby, the effective scattering mechanism(s). We constructed equipment to measure these four transport coefficients on the same sample over a temperature range of 30 – 350 K for thin films deposited on insulating substrates. We measured the resistivity, Hall, Seebeck, and Nernst coefficients for rf magnetron-sputtered aluminum-doped zinc oxide. We found that the effective mass for zinc oxide increases from a minimum value of 0.24me, up to a value of 0.47me, at a carrier density of 4.5 × 1020 cm−3, indicating a nonparabolic conduction energy band. In addition, our measured density-of-states effective values are nearly equal to conductivity effective mass values estimated from the plasma frequency, denoting a single energy minimum with a nearly spherical, constant-energy surface. The measured scattering parameter, mobility vs. temperature, along with Seebeck coefficient values, characterize ionized impurity scattering in the ZnO:AI and neutral impurity scattering in the undoped material.

scholarly journals Constraints on neutron stars equation of state using the tidal deformability derived from BNS mergers

2020 ◽  
Vol 27 ◽  
pp. 95
Author(s):  
Alkiviadis Kanakis-Pegios ◽  
Charalampos Moustakidis
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Binary System ◽  
Neutron Stars ◽  
Effective Mass ◽  
Lower Limit ◽  
Mathematical Formalism ◽  
Love Number ◽  
Binary Neutron Star ◽  
Upper Limit

The purpose of this work is the study of neutron stars (NS) equation of state (EOS) using constraints on tidal deformability derived from observation of binary neutron star (BNS) mergers, such as GW170817. The mathematical formalism is introduced, and then for a variety of EOS the system is solved numerically, allowing us to determine the mass, the radius, the tidal love number and the tidal deformability of the NS, each one of them unique for each EOS. Moreover, for a fixed value of chirp mass under the assumption that  m2<m1 (where m1 is the heavier component mass of BNS system), the effective (mass-weighted) tidal deformability of the binary system is determined for each EOS. We consider both an upper limit (GW170817) and a lower limit (AT2017gfo) for the effective tidal deformability. Also, we construct the Λ1-Λ2 space and we compare the behavior of EOS with the most recent LIGO’s data. We found out that the most EOS models give values for the effective tidal deformability less than the upper limit and that the most stiff EOS are excluded.

PNN and BP Neural Network Fault Diagnosis Research on Electronic Accelerator Pedal Detection

2020 ◽  
Vol 14 (2) ◽  
pp. 205-220
Author(s):  
Yuxiu Jiang ◽  
Xiaohuan Zhao
Keyword(s):  
Neural Network ◽  
Fault Diagnosis ◽  
Fault Detection ◽  
Lower Limit ◽  
Bp Neural Network ◽  
Accelerator Pedal ◽  
Electronic Throttle ◽  
Measured Voltage ◽  
Upper Limit ◽  
Network Fault

Background: The working state of electronic accelerator pedal directly affects the safety of vehicles and drivers. Effective fault detection and judgment for the working state of the accelerator pedal can prevent accidents. Methods: Aiming at different working conditions of electronic accelerator pedal, this paper used PNN and BP diagnosis model to detect the state of electronic accelerator pedal according to the principle and characteristics of PNN and BP neural network. The fault diagnosis test experiment of electronic accelerator pedal was carried out to get the data acquisition. Results: After the patents for electronic accelerator pedals are queried and used, the first measured voltage, the upper limit of first voltage, the first voltage lower limit, the second measured voltage, the upper limit of second voltage and the second voltage lower limit are tested to build up the data samples. Then the PNN and BP fault diagnosis models of electronic accelerator pedal are established. Six fault samples are defined through the design of electronic accelerator pedal fault classifier and the fault diagnosis processes are executed to test. Conclusion: The fault diagnosis results were analyzed and the comparisons between the PNN and the BP research results show that BP neural network is an effective method for fault detection of electronic throttle pedal, which is obviously superior to PNN neural network based on the experiment data.

scholarly journals Effect of Oxygen Source on the Various Properties of SnO2 Thin Films Deposited by Plasma-Enhanced Atomic Layer Deposition

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 692
Author(s):  
Jong Hyeon Won ◽  
Seong Ho Han ◽  
Bo Keun Park ◽  
Taek-Mo Chung ◽  
Jeong Hwan Han
Keyword(s):  
Electrical Properties ◽  
Atomic Layer Deposition ◽  
Carrier Concentration ◽  
High Mobility ◽  
Impurity Scattering ◽  
Atomic Layer ◽  
Growth Behavior ◽  
Layer Deposition ◽  
Growth Feature ◽  
O2 Plasma

Herein, we performed a comparative study of plasma-enhanced atomic layer deposition (PEALD) of SnO2 films using Sn(dmamp)2 as the Sn source and either H2O plasma or O2 plasma as the oxygen source in a wide temperature range of 100–300 °C. Since the type of oxygen source employed in PEALD determines the growth behavior and resultant film properties, we investigated the growth feature of both SnO2 PEALD processes and the various chemical, structural, morphological, optical, and electrical properties of SnO2 films, depending on the oxygen source. SnO2 films from Sn(dmamp)2/H2O plasma (SH-SnO2) and Sn(dmamp)2/O2 plasma (SO-SnO2) showed self-limiting atomic layer deposition (ALD) growth behavior with growth rates of ~0.21 and 0.07–0.13 nm/cycle, respectively. SO-SnO2 films showed relatively larger grain structures than SH-SnO2 films at all temperatures. Interestingly, SH-SnO2 films grown at high temperatures of 250 and 300 °C presented porous rod-shaped surface morphology. SO-SnO2 films showed good electrical properties, such as high mobility up to 27 cm2 V−1·s−1 and high carrier concentration of ~1019 cm−3, whereas SH-SnO2 films exhibited poor Hall mobility of 0.3–1.4 cm2 V−1·s−1 and moderate carrier concentration of 1 × 1017–30 × 1017 cm−3. This may be attributed to the significant grain boundary and hydrogen impurity scattering.

The Excavation of Eighteen Round Barrows near Shrewton, Wiltshire.

1984 ◽  
Vol 50 ◽  
pp. 255-318 ◽  
Author(s):  
Charles Green ◽  
Stephen Rollo-Smith ◽  
Elisabeth Crowfoot ◽  
Calvin Wells
Keyword(s):  
Water Supply ◽  
Lower Limit ◽  
Open Water ◽  
Linear Groups ◽  
Upper Limit ◽  
The Village

The excavation of eighteen round barrows was undertaken by the late Charles Green during summer seasons from 1958 to 1960, in advance of their destruction by ploughing. The excavated barrows are members of two linear groups which occupy adjacent spurs to the east of the village of Shrewton in the modern parish of that name (fig. 1). One of the barrows investigated lies in Winterbourne Stoke parish. This western part of Salisbury Plain is termed the ‘Lower Plain’ comprising those areas having their ‘upper limit… between 400 and 450 feet OD and their lower limit where they overlook the valley trenches … between 250 and 300 feet O.D.’ (Gifford 1957, 6). In such a lower valley lie the modern villages of Shrewton and Rollestone, and through it flows the river Till, the nearest modern open water supply to the barrows. This connects the area to the River Avon via the Wylye and Nadder.

scholarly journals PENGARUH PIJAT BAYI TERHADAP LAMA TIDUR BAYI DI DESA DUWET KECAMATAN WONOSARI KABUPATEN KLATEN

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Warsini Warsini ◽  
Dyah Nugraini
Keyword(s):  
Lower Limit ◽  
Sampling Technique ◽  
Infant Sleep ◽  
Not Given ◽  
Infant Massage ◽  
Natural Form ◽  
Upper Limit ◽  
Lack Of Information ◽  
Long Sleep ◽  
The Village

Background: Even the oldest massage is an activity used by humans to expelfatigue and stress. Lack of information and knowledge of parents of massage,makes many parents think a massage is not a scientific and natural form oftherapy for infants. Most mothers believe massage is necessary only when theirchild had flu and colds.Purpose of the study: To determine the effect of infant massage on infant sleepduration in the village of Duwet, Wonosari Subdistrict, Klaten Regency.The subject: The population in this study is a baby in the village of DuwetWonosari District of Klaten regency totaling 45 babies. Samples that met thestudy criteria and amounted to 20 babies. The sampling technique is simplerandom sampling.Methods: The data collection is done by the experimental method is bymeasuring how much sleep babies after intervention. Data were analyzed usingstatistical tests Independent t-test.The results: Long sleep in infants that give the infant massage is known that atleast 11 hours and a maximum of 18 hours with an average bed is 15.90 hours.Long sleep in infants who were not given the infant massage is known at least 12hours and a maximum of 17 hours with an average bed is 13.90 hours. Statisticalanalysis showed p: 3.967 with an upper limit 0.047 and lower limit 0.33.Conclusion: There is a statistically significant effect of infant massage with infantsleep duration (p: 3.967 with an upper limit 0.047 and lower limit 0.33).Keywords: infant massage, infant sleep duration

DEVELOPMENT AND DIAPAUSE IN PLEOLOPHUS BASIZONUS (HYMENOPTERA: ICHNEUMONIDAE)

1969 ◽  
Vol 101 (9) ◽  
pp. 907-914 ◽  
Author(s):  
K. J. Griffiths
Keyword(s):  
Lower Limit ◽  
Larval Mortality ◽  
Inverse Relation ◽  
Continuous Development ◽  
Upper Limit ◽  
Diapause Development ◽  
Diapause Incidence

AbstractThe upper limit for continuous development of Pleolophus basizonus lies between 25° and 30 °C since all stages develop at the former temperature and larval mortality is complete at the latter temperature. The lower limit lies between 5.5° and 10 °C, since an eonymphal diapause occurs at 5.5 °C. Between these extremes, diapause incidence varies inversely with temperature. The photoperiod experience of the parent has no effect on diapause in the progeny when the latter are reared at 15° and 18 °C, but there is an inverse relation between parental photoperiod experience and progeny diapause incidence at 10 °C. Although larvae and pupae also survive 3 months at 2 °C, most individuals probably overwinter in eonymphal diapause and their diapause requirements are fulfilled in 3 weeks at 2 °C. The incidence and rate of post-diapause development is directly related to temperature.

Runner System Design Optimization for Multigated and Multicavity Injection Molds

2000 ◽  
Author(s):  
Xiaoshi Jin
Keyword(s):  
Design Optimization ◽  
System Design ◽  
Lower Limit ◽  
Design Space ◽  
Injection Pressure ◽  
Cross Sectional ◽  
Upper Limit ◽  
System Design Optimization

Abstract Runner system design for injection molds with multiple gates or multiple cavities often requires iterative analyses for optimized results, because the gate locations or cavity shapes may not be naturally balanced. In addition, in molds with symmetrical layouts, the required injection pressure may be unnecessarily high if the runners are poorly sized. In this paper, a scheme for quickly optimizing runner system design is presented. The objective of design optimization is to minimize the required injection pressure within the design space defined by a given total runner volume. Each runner segment can be given an upper limit and lower limit to define the range of runner cross sectional dimensional size. Application examples are included to demonstrate the effectiveness of the scheme.

Sign in / Sign up

Export Citation Format

Share Document