Download or read book Observation of Quantum Confined Stark Effect in Triple Coupled InGaAs GaAs AlGaAs Quantum Well Infrared Photodetector written by and published by . This book was released on 1997 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have investigated the quantum-confined Stark effect (QCSE) in several n-type InGaAs/GaAs/AlGaAs triple-coupled quantum well infrared photodetectors (TC-QWIPs) for 8-12 micrometers long wavelength infrared (LWIR) detection. The basic structure of this TC-QWIP consists of three coupled quantum wells (QWs) formed by a Si-doped In(x)Ga(1-x)As QW and two undoped thin GaAs QWs separated by two thin Al(y)Ga(1-y)As barriers. Three TC-QWIP devices with varying indium and aluminum compositions were fabricated and characterized. A strong QCSE for the (E1 to E3) transition was observed in the wavelength range of 8.2 - 9.1 micrometers, 10.8 - 11.5 micrometers, and 9.4 - 10.7 micrometers for QWIP-A, -B, and -C, respectively. These devices exhibit a linear dependence of peak wavelength on the applied bias voltage over these wavelengths ranges. Peak responsivities, R(1) = 0.05, 0.33 A/W and detectivities, D(̂BLIP) = 6.1x10(exp9), l.63x10(exp10)cm-Hz(1/2)/W at V(b)=5, 4 V, lamba(p)=8.6, 11.2 micrometers, and T(BLIP)=66, 50 K were obtained for QWIP-A and -B, respectively. For QWIP-C, R(1)=0.19 A/W was obtained at lamba(p)=9.3 micrometers, V(b)=7 V, and T+60 K.

Download or read book Proceedings of the Fifth International Symposium on Long Wavelength Infrared Detectors and Arrays Physics and Applications written by Sheng S. Li and published by The Electrochemical Society. This book was released on 1997 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Meeting Abstracts written by Electrochemical Society. Meeting and published by . This book was released on 1997 with total page 3084 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Infrared Detectors and Focal Plane Arrays written by and published by . This book was released on 1998 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optically detected resonances induced by far infrared radiation in quantum wells and quantum dots written by Michael Gerbracht and published by GRIN Verlag. This book was released on 2008-07-18 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Doctoral Thesis / Dissertation from the year 2008 in the subject Physics - Theoretical Physics, grade: 1,0, University of Dortmund (Experimentelle Physik II), language: English, abstract: Abstract Photoluminescence (PL) and optically detected resonances (ODR) where studied on semiconductor quantum wells and quantum dots. Magnetic fields of up to 33 T where applied to samples at temperatures between 0.25 K and 10 K. In nonmagnetic quantum wells optically detected cyclotron resonance was used to determine basic properties such as effective mass and mobility of GaAs/AlGaAs quantum wells. In CdTe/CdMgTe quantum wells evidence for the singlet and triplet state of the negatively and positively charged exciton was found at high magnetic fields. In a highly n-type doped GaAs/AlGaAs quantum well, signatures of the fractional quantum hall effect were observed in PL and ODR data. Also shake up processes in a variety of quantum wells are discussed. In magnetic quantum wells, cusps in the exciton shift are present at moderate magnetic fields which could be assigned to next nearest neighbor interactions between Mn2+ ion pairs and single ions. Resonances in InGaAs/GaAs quantum dots induced by far-infrared radiation have been observed optically. They were studied in quantum dots with different confinement potential and under a series of tilting angles between sample normal and magnetic field direction. The resonances could be assigned to trion formation due to cyclotron resonance in the wetting layer and transitions in the internal energy structure of the dots. Also magnetic CdMnTe/ZnCdTe quantum dots with different Mn content were measured at magnetic fields up to 17 T. At low Mn concentrations a competition between the giant and intrinsic Zeeman splitting leads to a reduction of the polarization of the sample at high magnetic field which makes it possible to determine the Mn content by photoluminescence measurements.

Download or read book Physics Briefs written by and published by . This book was released on 1993 with total page 1058 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1996 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantum Interference Effect and Electric Field Domain Formation in Quantum Well Infrared Photodetectors written by and published by . This book was released on 1995 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: An observation of quantum interference effect in photocurrent spectra of a weakly coupled bound-to-continuum multiple quantum well photodetector is reported. This effect persists even at high biases where the Kronig Penney minibands of periodic superlattice potential in the continuum are destroyed. Our results show that electrons remain coherent over a distance of 40 50 nm. The observation was used to investigate electric field domain formation induced by sequential resonant tunneling in the superlattice. A large off-resonant energy level alignment between two neighboring wells in the high field domain was observed.

Download or read book Dissertation Abstracts International written by and published by . This book was released on 1998 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1987 with total page 1124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book SPIE Publications Index written by and published by . This book was released on 1992 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied Science Technology Index written by and published by . This book was released on 2000 with total page 1688 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index written by and published by . This book was released on 1994 with total page 1372 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantum Well Infrared Photodetectors written by Harald Schneider and published by Springer. This book was released on 2006-10-18 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Addressed to both students as a learning text and scientists/engineers as a reference, this book discusses the physics and applications of quantum-well infrared photodetectors (QWIPs). It is assumed that the reader has a basic background in quantum mechanics, solid-state physics, and semiconductor devices. To make this book as widely accessible as possible, the treatment and presentation of the materials is simple and straightforward. The topics for the book were chosen by the following criteria: they must be well-established and understood; and they should have been, or potentially will be, used in practical applications. The monograph discusses most aspects relevant for the field but omits, at the same time, detailed discussions of specialized topics such as the valence-band quantum wells.

Download or read book Wave Mechanics Applied to Semiconductor Heterostructures written by Gerald Bastard and published by EDP Sciences. This book was released on 1988 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examines the basic electronic and optical properties of two- dimensional semiconductor heterostructures based on III-V and II-VI compounds. Explores various consequences of one-dimensional size-quantization on the most basic physical properties of heterolayers. Beginning with basic quantum mechanical properties of idealized quantum wells and superlattices, it discusses the occurrence of bound states when the heterostructure is imperfect or when it is shone with near bandgap light.

Download or read book Fibre Optic Communication Devices written by Norbert Grote and published by Springer Science & Business Media. This book was released on 2001-01-26 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optoelectronic devices and fibre optics are the basis of cutting-edge communication systems. This monograph deals with the various components of these systems, including lasers, amplifiers, modulators, converters, filters, sensors, and more.

Download or read book Optical Nonlinearities and Instabilities in Semiconductors written by Hartmut Haug and published by Elsevier. This book was released on 2012-12-02 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical Nonlinearities and Instabilities in Semiconductors deals with various aspects of nonlinear optical phenomena and related optical instabilities in semiconductors. Measurements and explanations of the optical nonlinearities of various semiconductor materials and structures are presented, along with optical bistability and diode laser thresholds; self-oscillations; and chaos. This text consists of 17 chapters and begins with an introductory chapter to the historical background of investigations of the resonance-enhanced nonlinear optical properties of semiconductors and their manifestations in optical instabilities. The discussion then turns to the experimentally observed optical nonlinearities in homogeneous semiconductors and the microscopic theory of the optical band edge nonlinearities. This book considers the studies of the spectral region close to the band gap meant to exploit the resonance enhancement of the nonlinear optical behavior. The remaining chapters focus on nonlinear optical properties of semiconductor quantum wells; dense nonequilibrium excitations in gallium arsenide; optical decay and spatial relaxation; and optical bistability in semiconductor laser amplifiers. A chapter that describes instabilities in semiconductor lasers concludes the book. This book is intended for research students and active research workers who are interested in the basic physics or in the device applications of optical nonlinearities and instabilities in semiconductors.