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A comprehensive study, including growth, optical characterization and anisotropic transport in quantum well (QW), quantum wire (QWr), and quantum dot (QD) systems, is carried out for the InAs/InP nanostructures grown by gas-source molecular beam epitaxy on InP (001) substrates. Role of substrate misorientation in the self-organized formation, shape, and alignment of InAs nanostructures is investigated. The emission and absorption properties related to interband transitions of the InAs/InP nanostructures are studied by means of polarization-dependent photoluminescence (PL) and transmission spectroscopy. It is demonstrated that the emission wavelength of grown nanostructures extends up to 2 μm, including the technologically important 1.3 μm and 1.55 μm, at room temperature. Polarization-dependent PL and transmission measurements for all QWrs and QDs reveal much similarity in temperature behavior in spite of a qualitatively different character of the one (1D)- and zero (0D)-dimensional density-of-states functions. The in-plane transport of electrons and holes in QWrs, QDs, and QWs is investigated and interpreted in terms of anisotropic two-dimensional carrier systems, and in terms of coupled 1D or 0D systems. Peculiar band structure and carrier relaxation in the InAs/InP nanostructures suggest currently the large application potential for the optical devices – mainly for the telecommunication wavelength of 1.55 μm. [ABSTRACT FROM AUTHOR]

Graphene, which is a planar single sheet of sp2-bonded carbon atoms arranged in honeycomb lattice with superior electrical and heat conducting properties, has been proposed as material for future electronic circuits, sensors and detectors. Practical applications of graphene devices require an acceptable level of the low-frequency 1/fν electronic noise (f is frequency). We fabricated and investigated electronic noise characteristics in a set of back-gated and top-gated graphene field-effect transistors, which used single-layer and bi-layer graphene as the electrically conducting channel, and SiO2 and HfO2 as gate dielectrics. The Hooge parameter αH, which characterizes the noise level, for the single and bi-layer graphene devices is on the order of αH ∼ 10−4–10−3, which is comparable to that in the state-of-the-art devices made of conventional semiconductors. The generation – recombination (G-R) – type bulges in the noise spectra of some graphene devices suggest that the noise is of the carrier-number fluctuation origin and is caused by the charge carrier trapping and de-trapping by defects in graphene and SiO2 layer. The obtained experimental results are important for electronic and sensor applications of graphene. [ABSTRACT FROM AUTHOR]

This chapter begins with the stability considerations for a two-port network and the formulation of relevant conditions in terms of its scattering parameters. Expressions for input and output stability circles are presented next to facilitate the design of amplifier circuits. Design procedures for various small-signal single-stage amplifiers are discussed for unilateral as well as bilateral transistors. Noise figure considerations in amplifier design are discussed. An overview of broadband amplifiers is included. Small-signal equivalent circuits and biasing mechanisms for various transistors are also summarized. [ABSTRACT FROM PUBLISHER]

This article focuses on electron and hole mobility in semiconductor devices. Carrier mobility in a semiconductor is one of the most important parameters for the operation of electronic devices. Actually, the mobility measures the ability of free carriers. The magnitude of the mobility directly impacts on the device performance since it determines the operation speed through the transit time across the device, the circuit operating frequency, or the sensitivity in magnetic sensors. In practice, only two semiconductors, silicon and gallium arsenide, have been recognized as being the most suitable for the viewpoint of industrial standards.

Chapter 14 of the book "Introduction to molecular motion in polymers", is presented. It discusses the construction of two-dimensional conductor and long range electron mobility of carbon nanotubes through polyacetylene chains, the definition of single-walled nano tube (SWNT) and multi-walled nano tube (MWNT).