Semiconductor Physics

The most original and shocking interpretation of Lucretius in the last 40 years.

Thomas Nail argues convincingly and systematically that Lucretius was not an atomist, but a thinker of kinetic flux. In doing so, he completely overthrows the interpretive foundations of modern scientific materialism, whose philosophical origins lie in the atomic reading of Lucretius' immensely influential book De Rerum Natura.

This means that Lucretius was not the revolutionary harbinger of modern science as Greenblatt and others have argued; he was its greatest victim. Nail re-reads De Rerum Natura to offer us a new Lucretius--a Lucretius for today.

Diode is an electronic device having conductor at their ends. The principle behind the diode is similar to a valve or a gate, which lets electricity flow only in one direction (Simple English Wikipedia, Diode). Application of diodes is broad. They serve as converter from alternating current to direct current, met at the power supplies. Also they can be used in radio equipment to decode amplitude modulation. Nowadays, there are two basic semiconductor materials which the diode is made from: silicon and germanium
Two types of semiconductors are joined to each other to produce semiconductor diode. One of them has spare holes (p side), and the other has extra electrons (n side). This results in the flow of electrons from the side, where there are more electrons to the side where there are less of them, i.e. current. However, it is difficult to flow for the current in the reverse direction. Connecting electrodes are following: positive p-side is anode, and negative n-side is cathode.

A charged photon and its light-speed helical trajectory form a surprising new solution to the relativistic electron’s energy-momentum equation. This charged photon model is a new model for the electron, and quantitatively resembles the light-speed electron described by Dirac. The charged photon model of the electron is found to quantitatively predict the relativistic de Broglie wavelength of the free electron. This suggests a new interpretation of quantum mechanics, where the electron is seen as a charged photon, and the quantum mechanical wave equations for the electron are generated by the waves produced by the circulating charged photon that composes the electron.

This research was funded by, and implemented within, a UK national research organisation, while the author was the KE and Impact Evaluation Manager responsible for assessing impact on a £15m UK government-funded research programme.

This work was also submitted as the authors MBA dissertation which was accepted and awarded in 2009.

ABSTRACT: A methodology and methods ‘toolbox’ is proposed for conducting impact research and assessment from within research programmes. The emphasis is upon how to clarify and assess the wider impacts from the early stages onwards.

The approach explicitly acknowledges, and attempts to address, the known issues and challenges of impact assessment while drawing upon the resources and opportunities available to research managers and researchers within such programmes.

The study has two triangulating foundations. Firstly, it examines the academic literature to help identify and design the pilot methodology and methods. Secondly it trials these in a real programme to both test and improve them.

The study was conducted over one year within one leading UK research organisation, where two research programmes (and around 60 research projects of £15m total value) were being assessed for their impacts. The study draws upon actual impact management experience and reflection, prospective (ex ante) and retrospective (ex post) assessments, participatory contributions from leading researchers undergoing assessment, and consultation with external users. The findings of this study outline the pilot and its first iteration. Recommendations are made for improvement to the methodology and methods.

A subsequent follow-on bid to UK government incorporating the impacts identified from implementing this methodology, successfully led to a further £15m of government funding.

It is expected the pilot methodology and methods will be applicable to other organisations, conducting and funding such research programmes, required to research and assess the wider research impacts.

Although primary focus of implemetation trials was upon research in physical sciences, technology, high-tech engineering, computing/IT, and environment, the wider literature study, the methodology design and justification, the methods proposed and used, and the resulting general recommendations and lessons are expected to apply more broadly to many other research areas, where the impact is to be found more widely in the society, economy, government or public sector or within organizations, policies, professions or the public.

Interest in this work is expected from research programme managers, impact managers and assessors, management consultants advising in this area, and government funding managers, all seeking to embed a developing approach to understand, capture, and enhance wider impact.

Operational Amplifier (Op Amp) is a three terminal electronic device which has two inputs of high impedance. The first input is called inverting (represented by ‘-‘), and the other terminal is called non-inverting input. The third terminal serves as output port, where signal is usually amplified by some gain (A), depending on the nature of op amp and input characteristics. 
In this lab session we build op amp circuits and carry out various calculations of op amp characteristics. At the end of this lab, we are to strengthen theoretical knowledge by gaining hands on experience. This lab covers:
- Inverting Amplifiers 
- Non-inverting Amplifiers 
- Summing Amplifiers

A superluminal quantum-vortex model of the electron and the positron is produced from a superluminal double-helix model of the photon during electron-positron pair production. The two oppositely-charged (with Q = ±e sqrt (2/α) = 16.6e) open-helix spin-½ half-photons compose the double-helix photon. These half-photons separate and curl up their separated superluminal single-helical trajectories to form an electrically-charged superluminal closed-helix spin-½ quantum-vortex electron model and a corresponding positron model. The helical radius and the Dirac equation's zitterbewegung angular frequency of the quantum vortex electron and positron models equal the helical radius and zitterbewegung angular frequency of the two spin-½ half-photons, each of energy E = mc^2 , that composed the double-helix photon model of energy E = 2mc^2 from which the electron and positron models were produced. The photon and electron models are also compatible when a photon of energy E > 2mc^2 produces a relativistic electron-positron pair. Implications of the quantum vortex electron model for electron stability are discussed.

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Read first:
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Wisdom and these great writings are priceless and should be free to access for everybody. We made this available for those who cannot pay the actual price of the e-copy. The whole credit goes to the writer and publication company.
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It is a solution manual for "Electronic device and circuit theory 11th edition By Robert L. Boylestad".
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- The Solar Planets order proves that, the planet orbital distance is defined based on his Diameter and NOT his Mass, which disproves the Gravity Theory..

But
- Planet Diameter and Orbital Distance Relationship Equation is so hard to define…! Why?

Because
- The solar Group has 2 Heads (The Sun and Earth).
The Solar Group is A Dipole….

We need to modify the Solar Group Basic Description to be " A Dipole System"… 
 
- This paper also discusses the Sun nature and Origin…

This paper reviews the device physics and technology of optoelectronic devices based on semiconductors of the GaN family, operating in the spectral regions from deep UV to Terahertz. Such devices include LEDs, lasers, detectors, electroabsorption modulators and devices based on intersubband transitions in AlGaN quantum wells (QWs). After a brief history of the development of the field, we describe how the unique crystal structure, chemical bonding, and resulting spontaneous and piezoelectric polarizations in heterostructures affect the design, fabrication and performance of devices based on these materials. The heteroepitaxial growth and the formation and role of extended defects are addressed. The role of the chemical bonding in the formation of metallic contacts to this class of materials is also addressed. A detailed discussion is then presented on potential origins of the high performance of blue LEDs and poorer performance of green LEDs (green gap), as well as of the efficiency reduction of both blue and green LEDs at high injection current (efficiency droop). The relatively poor performance of deep-UV LEDs based on AlGaN alloys and methods to address the materials issues responsible are similarly addressed. Other devices whose state-of-the-art performance and materials-related issues are reviewed include violet-blue lasers, 'visible blind' and 'solar blind' detectors based on photoconductive and photovoltaic designs, and electroabsorption modulators based on bulk GaN or GaN/AlGaN QWs. Finally, we describe the basic physics of intersubband transitions in AlGaN QWs, and their applications to near-infrared and terahertz devices.

This Impact Report identifies and summarises the diverse impacts, resulting from the £500m of UK funding of Science and Technology in 2013, using numerous quantitative metrics and short case study extracts.  It shows how the varied impacts of a national science and technology organization and its many funded programmes can be annually identified, captured, tracked, and summarised in a public document.

The report was produced for, and by, the Science and Technology Facilities Council (STFC) -  the UK Research Council responsible for funding: (1) all UK astronomy, particle and nuclear physics research, (2) related UK science and technology facilities (e.g. as Harwell and Daresbury), (3) the UK contribution to international science (e.g. CERN, international telescopes and space missions), (4) innovation and business spin-off programmes, and (5) UK public engagement activities.

The Report was co-researched and co-authored by the STFC Impact Team, including myself while Impact Evaluation Manager in 2013, with Dr. Claire Dougan-McCallie (lead author/Head of Impact) and Jenny Beard, with additional input from senior managers, and many data and case study contributions from other key managers across STFC.

Varied key impacts are identified and reported including:

• Research amongst the best (by citation impact) in astronomy, nuclear and particle physics.
• Supported research of 226 Principal Investigators in 70 universities, led to 1,100 peer-reviewed papers in 2012.
• Facilities (the Diamond Light Source, ISIS and CLF) were used in 2012/13 by over 4,200 unique users , in over 2,400 experiments, producing over 1,000 papers in peer-reviewed journals.

• Technology from CERN benefited the UK economy by over £100 billion every year.
• Funding the development of the UK’s space, internet and computer animation industries, returned over £500 billion to the UK economy per annum.
• Funded Innovation Campuses hosted over 230 enterprises and supported over 5,000 jobs.
• UK industry won £43 million in contracts from the international subscriptions funded, and had accumulated a total of £150 million since 2005.

• Funded research inspired future generations to study STEM subjects, attracting 90% of UK undergraduates to study physics, funded 782 PhD students  and 16,800 student training days.
• Between 2009 to 2012 public engagement programmes engaged people on 58 million occasions, with 2 million people engaged in face-to-face activities in 2013 alone.

A superluminal quantum-vortex model of the electron and the positron is produced from a superluminal double-helix model of the photon during electron-positron pair production. The two oppositely-charged (with Q = ±e sqrt(2/α) = 16.6e) open-helix spin-½ half-photons compose the double-helix photon. These half-photons separate and curl up their separated superluminal single-helical trajectories to form an electrically-charged superluminal closed-helix spin-½ quantum-vortex electron model and a corresponding positron model. The helical radius and the Dirac equation's zitterbewegung angular frequency of the quantum vortex electron and positron models equal the helical radius and zitterbewegung angular frequency of the two spin-½ half-photons, each of energy E = mc^2, that composed the double-helix photon model of energy E = 2mc^2 from which the electron and positron models were produced. The photon and electron models are also compatible when a photon of energy E > 2mc 2 produces a relativistic electron-positron pair. Implications of the quantum vortex electron model for electron stability are discussed.

The Earth moves with C velocity (light velocity) relative to the Sun
i.e.
The light is produced by The Earth Motion, where
The Earth transforms her motion mechanical waves into light waves, producing the light beams   
These light beams travel to the sun and reflect on her where the sun is just a mirror. 

The Earth Motion = The Solar Planets Daily Velocities Total based on new time rate defined by the Earth.

This article shows how the charged photon model of the electron is consistent with the time-dependent and the time-independent forms of the one-dimensional Schrödinger equation, which describes the conservation of total energy of a non-relativistic charged photon in the presence of an electric potential.

Why there's No velocity higher than Light Velocity C =300000 km/sec? Because • The Matter is created from light beams coherence (according to Young Experiment-The Main Hypothesis) • The Time is created as the Matter Changing measurement • Our body (matter) is produced by the same method, from this light beams coherence • Our bodies are connected with specific Light velocity and specific time rate because our bodies are produced by specific Light Beams coherence

Of the III-Nitride family the AlN/GaN heterojunction has demonstrated the largest combined polarization charge and energy band osets available in the system. Engineering the polarization fields through varying the AlN thickness leads to two-dimensional electron gas densities (2DEGs) that may be tailored between 0.5 - 5 x1013 cm􀀀2. Furthermore, the ultra-thin (< 5 nm) barrier and excellent transport properties of this all binary heterostructure make it well suited for high electron mobility transistor applications where high frequency and high current are required. This work encompasses various design aspects of GaN-based High Electron Mobility Transistors (HEMTs) which ultimately result in the realization of several generations that utilize the AlN/GaN heterostructure.

HEMTs fabricated from high-mobility, low sheet resistance heterostructures have achieved drain current densities up to 2.3 A/mm and transconductance of 480 mS/mm, which set new benchmarks for GaN-based HEMTs. Ultra-thin pre-metallization etching has been employed for the rst time to reduce ohmic contact resistance for AlN/GaN HEMTs and has enabled small signal frequency performance in excess of 100 GHz. Moll's method for delay time extraction has been utilized to extract an effective electron velocity in the intrinsic region of the AlN/GaN HEMT and was found to be  1.2 x107 cm/s.

By leveraging the allowable thickness window of the AlN barrier along with the high density 2DEGs that result, several novel HEMT devices have been designed and realized. High Al-content AlxGa1􀀀xN back barriers have been employed for improved 2DEG confinement in several new variations of the ultra-thin AlN/GaN HEMT. A dual, parallel-channel AlN/GaN-based HEMT structure is designed and realized for the first time as an epitaxial approach to mitigating DC-RF frequency dispersion. These structures emphasize the facilitation of new device designs that are made possible through the particular qualities the AlN/GaN heterostructure possesses.

— As the demand grow for the very High Performance and high density integrated circuit, MOSFET scaling to submicron regimes will continue to be at the core of the device and circuit design. While the circuit dimensions are reduced, circuit requirements demand maintaining long channel behavior and minimizing the short channel as well as parasitic effects or also punch through effects. At the same time, higher current drivability requires thinner gate oxides in shorter channel length devices. The effect of scaling on initial device characteristics, the limit imposed by reliability concern in scale down MOSFET technologies, techniques to control short channel effects and unconventional approach to MOSFET scaling.

Most digital designers will never be confronted with the details of the manufacturing process that lies at the core of the semiconductor revolution. Yet, some insight in the steps that lead to an operational silicon chip comes in quite handy in understanding the physical constraints that are imposed on a designer of an integrated circuit, as well as the impact of the fabrication process on issues such as cost. In this chapter, we briefly describe the steps and techniques used in a modern integrated circuit manufacturing process. It is not our aim to present a detailed description of the fabrication technology, which easily deserves a complete course [Plummer00]. Rather we aim at presenting the general outline of the flow and the interaction between the various steps. We learn that a set of optical masks forms the central interface between the intrinsics of the manufacturing process and the design that the user wants to see transferred to the silicon fabric. The masks define the patterns that, when transcribed onto the different layers of the semiconductor material, form the elements of the electronic devices and the interconnecting wires. As such, these patterns have to adhere to some constraints in terms of minimum width and separation if the resulting circuit is to be fully functional. This collection of constraints is called the design rule set, and acts as the contract between the circuit designer and the process engineer. If the designer adheres to these rules, he gets a guarantee that his circuit will be manufacturable. An overview of the common design rules, encountered in modern CMOS processes, will be given. Finally, an overview is given of the IC packaging options. The package forms the interface between the circuit implemented on the silicon die and the outside world, and as such has a major impact on the performance, reliability, longevity, and cost of the integrated circuit. 2.2 Manufacturing CMOS Integrated Circuits A simplified cross section of a typical CMOS inverter is shown in Figure 2.1. The CMOS process requires that both n-channel (NMOS) and p-channel (PMOS) transistors be built in the same silicon material. To accommodate both types of devices, special regions called wells must be created in which the semiconductor material is opposite to the type of the channel. A PMOS transistor has to be created in either an n-type substrate or an n-well, while an NMOS device resides in either a p-type substrate or a p-well.

In the etching and deposition steps in the production of semiconductor chips, plasma processing is required for three main reasons. First, electrons are used to dissociate the input gas into atoms. Second, the etch rate is greatly enhanced by ion bombardment, which breaks the bonds in the first few monolayers of the surface, allowing the etchant atoms, usually Cl or F, to combine with substrate atoms to form volatile molecules. And third, most importantly, the electric field of the plasma sheath straightens the orbits of the bombarding ions so that the etching is anisotropic, allowing the creation of features approaching nanometer dimensions. The plasma sources used in the semiconductor industry were originally developed by trial and error, with little basic understanding of how they work. To achieve this understanding, many challenging physics problems had to be solved. This chapter is an introduction to the science of radiofrequency (RF) plasma sources, which are by far the most common. Sources operating at zero or other frequencies, such as 2.45 GHz microwaves, lie outside our scope. Most RF sources use the 13.56 MHz industrial standard frequency. Among these, there are three main types: (1) capacitively coupled plasmas or CCPs, also called reactive ion etchers (RIEs); (2) inductively coupled plasmas (ICPs), also called transformer coupled plasmas (TCPs); and (3) helicon wave sources, which are new and can be called HWSs.

In order to interpret the electrical characteristics of fabricated Au/ZnO/n-Si structures as a function of frequency and voltage well, their capacitance– voltage (C–V) and conductance–voltage (G/x–V) measurements were carried out in a wide range of frequencies (0.7 kHz–2 MHz) and voltages (± 6 V) by 50 mV steps at room temperature. Both the C–V and G/x–V plots have reverse, depletion, and accumulation regions such as a metal–insulator/oxide semiconductor (MIS or MOS) structures. The values of doped-donor atoms (N D), Fermi energy level (E F), barrier height (U B), and series resistance (R s) of the structure were obtained as a function of frequency and voltage. While the value of N D decreases with increasing frequency almost as exponentially, the value of depletion width (W D) increases. The values of C and G/x increase with decreasing frequency because the surface states (N ss) are able to follow the alternating current (AC) signal, resulting in excess capacitance (C ex) and conductance (G ex /x), which depends on their relaxation time and the frequency of the AC signal. The voltage-dependent profiles of N ss were obtained from both the high–low frequency capacitance and Hill-Colleman methods. The other important parameter R s of the structure was also obtained from the Nicollian and Brews methods as a function of voltage.

The effect of self-heating on the transport characteristics and electronic properties of transistor AlGaN/GaN heterostructures was investigated. The electrical, micro-Raman and photoluminescence techniques were used for temperature estimations for transistor structures under electrical load. The thermal resistance of these structures has been calculated to obtain the temperature of conducting channel heating from the current-voltage characteristics. The differences in the obtained temperature data from applied techniques have been analyzed.

The aim of the laboratory work is to understand the principle of Zener diode operation and also apply the knowledge practically by completing laboratory tasks. 
In this part, limiting circuit is described in Figure 1 above. The trimmer resistance is varied, so that the voltage at cathode of the D9 diode changes. Initially, it is set up to +12 V, then 0 V, and finally to -12V.  Case RV4 = +12V: When the current flows from the AC input voltage (Vin = +10V) during the positive half, the D9 diode is reverse biased and the input voltage equals output voltage. During the negative half, diode is still closed. Hence, obtained pattern is provided in Figure 2.

Usaha untuk mengembangkan sistem pengkondisian udara
dapat dilakukan dengan memanfaatkan teknologi elektronika yang telah berkembang yaitu teknologi semikonduktor. Konsep dasar aplikasi teknologi semikonduktor untuk sistem pengkondisian udara ini adalah memanfaatkan hubungan material semikonduktor tipe-p dan tipe-n untuk menyerap ataupun membuang panas saat memperoleh aliran arus listrik berdasarkan efek Peltier dan efek Seebeck. Dengan aplikasi material semikonduktor sebagai sistem pengkondisian udara maka sistem penyegar udara akan  menjadi lebih sederhana dan lebih mudah dalam perawatan.

The results of an ongoing collaborative project between the New Jersey Institute of Technology (NJIT) and SEMATECH on the temperature-dependent emissivity of silicon-related materials and structures are presented in this study. These results have been acquired using a spectral emissometer. This emissometer consists of a Fourier Transform Infra-Red (FTIR) spectrometer designed specifically to facilitate simultaneous measurements of surface spectral emittance and temperature by using optical techniques over the near- and mid-IR spectral range and temperatures ranging from 300 K to 2000 K. This noncontact, real-time technique has been used to measure radiative properties as a function of temperature and wavelength for a wide range of silicon-related materials and structures. The first results of the temperature and wavelength dependent emissivity and hence refractive index of silicon nitride, in the literature, is presented in this study

Dissipative environment/quantum dissipation QUAPI Phonon damped laser driven quantum dot qubit Tensor propagator algorithm Memory kernel a b s t r a c t This MATLAB program calculates the dynamics of the reduced density matrix of an open quantum system modeled either by the Feynman-Vernon model or the Caldeira-Leggett model. The user gives the program a Hamiltonian matrix that describes the open quantum system as if it were in isolation, a matrix of the same size that describes how that system couples to its environment, and a spectral distribution function and temperature describing the environment's influence on it, in addition to the open quantum system's initial density matrix and a grid of times. With this, the program returns the reduced density matrix of the open quantum system at all moments specified by that grid of times (or just the last moment specified by the grid of times if the user makes this choice). This overall calculation can be divided into two stages: the setup of the Feynman integral, and the actual calculation of the Feynman integral for time propagation of the density matrix. When this program calculates this propagation on a multi-core CPU, it is this propagation that is usually the rate-limiting step of the calculation, but when it is calculated on a GPU, the propagation is calculated so quickly that the setup of the Feynman integral can actually become the rate-limiting step. The overhead of transferring information from the CPU to the GPU and back seems to have a negligible effect on the overall runtime of the program. When the required information cannot fit on the GPU, the user can choose to run the entire program on a CPU.

In this paper we create a self similar
analogous image of spiral structure
of elementary particles with that of
sea shells, using the mathematical
description of pigmentation pattern
of sea shells, which describes the
various potentials of the spiral
structure of elementary particles. It
also introduces the sea shells
analogous parameters for spiral
structure of elementary particles for
quantising the property of the
elementary particles. It applies the
Reaction-Diffusion equation for
Activator-Inhibitor model to produce
the ingredient activated potential
which once after the formation of the
spiral structure of elementary
particles is being described by the
Activator- Substrate model.

In this paper we have tried to deduce the possible origin of particle and evolution of their intrinsic properties through spiral dynamics.  We consider some of the observations which include exponential mass function of particles following a sequence when fitted on logarithmic potential spiral, inwardly rotating spiral dynamics in Reaction-Diffusion System, the separation of Electron’s Spin-Charge-Orbit into quasi-particles. The paper brings a picture of particles and their Anti Particles in spiral form and explains how the difference in structure varies their properties. It also explains the effects on particles in Accelerator deduced through spiral dynamics.

The pioneering exfoliation of monolayer tungsten diselenide has greatly inspired researchers toward semiconducting applications. WSe 2 belongs to a family of transition-metal dichalcogenides. Similar to graphene, WSe 2 and analogous dichalcogenides have layered structures with weak van der Waals interactions between two adjacent layers. First, the readers are presented with the fundamentals of WSe 2, such as types, morphologies, and properties. Here, we report the characterization principles and practices such as microscopy, spectroscopy, and diffraction. Second, the methods for obtaining high-quality WSe 2 , such as exfoli-ation, hydrothermal and chemical vapor deposition, are briefly listed. With advantages of light weight, flexibility, and high quantum efficiency, 2D materials may have a niche in optoelectronics as building blocks in p-n junctions. Therefore , we introduce a state-of-the-art demonstration of heterostructure devices employing the p-type WSe 2 semiconductor. The device architectures include field-effect transistors, photodetectors, gas sensors, and photovoltaic solar cells. Due to its unique electronic, optical, and energy band properties, WSe 2 has been increasingly investigated due to the conductivity of the p-type charge carrier upon palladium contact. Eventually, the dynamic research on WSe 2 and van der Waals heterostructures is summarized to arouse the passion of the 2D research community. Qilin Cheng, Jinbo Pang, and Dehui Sun contributed equally to this study.

The article analyse different configurations of a 100 MV Peak DC Fixed Tilted Polycrystalline Photovoltaic (PV) Solar Power Plant. The article first defines the general layout of the plant than it outlines certain fixed parameters such as plant location, its weather data, wiring losses and  soiling losses etc. The aim of the article is to show how certain fixed design parameters such as PV module selection, Inverter selection and distance between the arrays can effect the production loss or in other words the Performance Ratio (PR) of the plant. For this purpose a series of simulations have been carried out which are described in detail in the article.

Au/graphene oxide (GO)-doped PrBaCoO nanoceramic/n-Si capacitors were fabricated and their admittance measurements were carried out between 1 kHz and 1 MHz at room temperature. Experimental results showed that the capacitance (C) and conductance (G/w) values are strong functions of frequency and applied bias voltage. C–V plot revealed two distinctive peaks at low frequencies which are located at about 0 and 2 V, such that the first peak disappears towards high frequencies. The energy density distribution profile of the interface/surface states (D it / N ss) and their relaxation time (s) and capture cross section (r p) of the sample were obtained by using the admittance method. In addition, the voltage-dependent profile of N ss and resistance were obtained by using low–high frequency capacitance and Nicollian-Brews method, respectively, and they also reveal two distinctive peaks, respectively. Two peaks' behavior in the forward bias C–V, N ss –V and R i –V plots confirmed the existence of two different localized regions of N ss between Si and interfacial layer. The series resistance (R s) of the device decreased with increasing frequency from 175 X at 1 kHz to 72 X at 1 MHz. As a result, the mean value of D it was found about 5 9 10 13 eV-1 cm-2 which is reasonable for an electronic device.

The dielectric properties of Au/(1 % graphene
doped-Ca1.9Pr0.1Co4Ox)/n-Si structures were investigated
by the impedance spectroscopy method including capacitance–
voltage (C–V) and conductance–voltage (G/x–
V) measurements in the frequency range of 10–2 MHz at
room temperature. The experimental results show that the
real and imaginary parts of dielectric constant (e0, e00) and
electric modulus (M0 andM00), and ac electrical conductivity
(rac) are a strong functions of frequency and voltage, both.
Negative dielectric constant behavior was observed at sufficiently
high forward bias voltages at low frequencies and it
was attributed to the interfacial polarization, interface traps
and series resistance. e0 decreases with increasing frequency
at sufficiently high biases whereas e00 increases. Since
interfacial polarization and interface states, both, can follow
the ac external signal easily at low frequencies, there occurs
a contribution to the measured capacitance and conductance.
The negative values of e0 correspond to maximum value of
e00. Such contrary behavior in the e0 and e00 appears as an
abnormality when compared to the conventional behavior
metal–semiconductor structures with and without interfacial
layer. Experimental results confirmed that the dielectric
properties of these structures are quite sensitive to the frequency and applied bias voltage, both, especially at low
frequencies and high voltages because of density distribution
of interface states and interfacial polarization.

Sputtering has been well-developed industrially with singular ambient gases including neutral argon (Ar), oxygen (O2), hydrogen (H2) and nitrogen (N2) to enhance the electrical and optical performances of indium tin oxide (ITO) films. Recent preliminary investigation into the use of combined ambient gases such as an Ar+O2+H2 ambient mixture, which was suitable for producing high-quality (low sheet resistance and high optical transmittance) of ITO films. To build on this promising preliminary work and develop deeper insight into the effect of ambient atmospheres on ITO film growth, this study provides a more detailed investigation of the effects of ambient combinations of Ar, O2, H2 on sputtered ITO films. Thin films of ITO were deposited on glass substrates by DC magnetron sputtering using three different ambient combinations: Ar, Ar+O2 and Ar+O2+H2. The structural, electrical and optical properties of the three ambient sputtered ITO films were systematically characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman spectroscopy, four probe electrical conductivity and optical spectroscopy. The XRD and Raman studies confirmed the cubic indium oxide structure, which is polycrystalline at room temperature for all the samples. AFM shows the minimum surface roughness of 2.7 nm for Ar+O2+H2 sputtered thin film material. The thickness of the films was determined by the cross sectional SEM analysis and its thickness was varied from 920 to 817 nm. The columnar growth of ITO films was also discussed here. The electrical and optical measurements of Ar+O2+H2 ambient combinations shows a decreased sheet resistance (5.06 ohm/□) and increased optical transmittance (69%) than other samples. The refractive index and packing density of the films were projected using optical transmission spectrum. From the observed results the Ar+O2+H2 ambient is a good choice to enhance the total optoelectronic properties of the ITO films. The improved electrical and optical properties of ITO films with respect to the Ar+O2+H2 ambient sample were discussed in detail. In addition, the physical properties were also discussed with the influence of this ambient combination with respect to Ar, Ar+O2 and Ar+O2+H2.

In order to compare the main electrical parameters such as ideality factor (nn), barrier height (BH) (ΦI–VΦI–V), series (RsRs) and shunt (RshRsh) resistances and energy density distribution profile of surface states (NssNss), the Au/nn-Si (MS) Schotthy diodes (SDs), with and without interfacial (Ca1.91.9Pr0.10.1Co4Oxx) layer were obtained from the current–voltage (II–VV) measurements at room temperature. The other few electrical parameters such as Fermi energy level (EFEF), BH (ΦC–VΦC–V), RsRs and voltage dependence of NssNss profile were also obtained from the capacitance–voltage (CC–VV) measurements. The voltage dependence of NssNss profile has two distinctive peaks in the depletion region for two diodes and they were attributed to a particular distribution of NssNss located at metal–semiconductor (MS) interface. All of these results have been investigated at room temperature and results have been compared with each other. Experimental results confirmed that interfacial (Ca1.91.9Pr0.10.1Co4Oxx) layer enhanced diode performance in terms of rectifier rate (RR=IF/IRIF/IR at ±3.4 V), NssNss (at 0.5 eV) and RshRsh (−3.4−3.4 V) with values of 265, 5.38×10135.38×1013eV−1⋅−1⋅cm−2−2 and 7.87×104Ω7.87×104Ω for MS type Schottky barrier diode and 2.56×1062.56×106, 1.15×10131.15×1013 eV−1⋅−1⋅cm−2−2 and 7.50×108Ω7.50×108Ω for metal–insulator–semiconductor (MIS) type SBD, respectively. It is clear that the rectifying ratio of MIS type SBD is about 9660 times greater than MS type SBD. The value of barrier height (BH) obtained from CC–VV data is higher than the forward bias II–VV data and it was attributed to the nature of measurements. These results confirmed that the interfacial (Ca1.91.9Pr0.10.1Co4Oxx) layer has considerably improved the performance of SD.