Download or read book Luminescence and Related Properties of II VI Semiconductors written by D. R. Vij and published by Nova Publishers. This book was released on 1998 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides the readers an in-depth, yet concise, overview of the physico-chemical structures, luminescence and related properties of II-VI compounds which are being utilised and exhaustively studied these days for their applications in LED's, modern optoelectronic devices, flat EL screens and panels, infrared detectors, photovoltaic and thermal solar energy converters etc. The book, therefore, should be useful to a wide variety of people (working in the field of luminescence and related properties of II-VI compounds, i.e. advanced graduate students) and serve as a review to researchers entering in this field and working on these materials. It should also be useful to solid state spectroscopists, lasers physicists; electronic and illuminating engineering people, and all those professionals using these materials.

Download or read book Ii vi Semiconductor Compounds written by Mukesh Jain and published by World Scientific. This book was released on 1993-05-04 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: X-Ray Characterisation of II-VI Semiconductor Materials (D Gao et al.)Electronic Structure of II-VI Semiconductors and Their Alloys (S-H Wei)Radiative Recombination Processes in Rare Earth Doped II-VI Materials (M Godlewski et al.)Nonlinear Optical Properties of Heavily Doped CdS (U Neukirch)Nanostructures of Broad Gap (II,Mn) VI Semiconductors (W Heimbrodt & O Goede)Co-Based II-VI Semimagnetic Semiconductors (A Twardowski et al.)Photoluminescence and Raman Scattering of ZnSe-ZnTe Strained Layer Superlattices (K Kumazaki)Novel Electronic Processes in Mercury-Based Superlattices (J R Meyer et al.)Strain, Pressure and Piezoelectric Effects in Strained II-VI Superlattices and Heterostructures (E Anastassakia)Electronic Structures of Strained II-VI Superlattices (T Nakayama)Devices and Applications of II-VI Compounds (S Colak)Solar Cells Based on II-VI Semiconductors (H Uda)ZnSe and Its Applications for Blue-Light Laser Diodes (M Pessa & D Ahn)Molecular Beam Epitaxy of HgCdTe for Electro-Optical Infrared Applications (J M A Cortés)and other papers Readership: Condensed matter physicists and electronic engineers. keywords:

Download or read book Luminescence Properties of Rare Earth Doped III V and II VI Semiconductors written by Amer K. Alshawa and published by . This book was released on 2000 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optical Properties of Wide Band Gap II VI Semiconductors written by and published by . This book was released on 1992 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Growth and Optical Properties of Wide Gap II VI Low Dimensional Semiconductors written by T.C. McGill and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the Proceedings of the NATO Advanced Research Workshop on "Growth and Optical Properties of Wide Gap II-VI Low Dimensional Semiconductors", held from 2 - 6 August 1988 in Regensburg, Federal Republic of Germany, under the auspices of the NATO International Scientific Exchange Programme. Semiconducting compounds formed by combining an element from column II of the periodic table with an element from column VI (so called II-VI Semiconductors) have long promised many optoelectronic devices operating in the visible region of the spectrum. However, these materials have encountered numerous problems including: large number of defects and difficulties in obtaining p- and n-type doping. Advances in new methods of material preparation may hold the key to unlocking the unfulfilled promises. During the workshop a full session was taken up covering the prospects for wide-gap II-VI Semiconductor devices, particularly light emitting ones. The growth of bulk materials was reviewed with the view of considering II-VI substrates for the novel epitaxial techniques such as MOCVD, MBE, ALE, MOMBE and ALE-MBE. The controlled introduction of impurities during non-equilibrium growth to provide control of the doping type and conductivity was emphasized.

Download or read book Optical Properties of II VI Semiconductor Materials and Superlattice Structures written by Tuyen K. Tran and published by . This book was released on 1996 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Room Temperature Injection Luminescence in II VI Semiconductors written by David L. Kennedy and published by . This book was released on 1972 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: The luminescent properties of ZnSe and ZnS crystals prepared by a number of techniques were investigated and compared with the electroluminescence properties of M-s and M-i-s device structures. Experiments relating to the preparation of heterojunction structures by the application of close-spaced epitaxial techniques to the vapor deposition of ZnSe films on compatible substrates were also conducted and the potential application of III-V - II-VI alloy crystals to this type of device evaluated. A method was developed to prepare heterstructures by solution growth, of GaAs and ZnSe, GaP on ZnS and GaP on ZnSe. Growth of wafers GaInP for application to heterojunction structures was investigated using similar solution growth methods. In the evaluation of the optical properties of heterojunction structures, a high-resolution spectrograph was developed. (Author).

Download or read book Handbook of II VI Semiconductor Based Sensors and Radiation Detectors written by Ghenadii Korotcenkov and published by Springer Nature. This book was released on 2023-03-30 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reference provides interdisciplinary discussion for diverse II-VI semiconductors with a wide range of topics. The third volume of a three volume set, the book provides an up-to-date account of the present status of multifunctional II-VI semiconductors, from fundamental science and processing to their applications as various sensors, biosensors, and radiation detectors, and based on them to formulate new goals for the further research. The chapters in this volume provide a comprehensive overview of the manufacture, parameters and principles of operation of these devices. The application of these devices in various fields such medicine, agriculture, food quality control, environment monitoring and others is also considered. The analysis carried out shows the great potential of II-VI semiconductor-based sensors and detectors for these applications. Considers solid-state radiation detectors based on semiconductors of II-VI group and their applications; Analyzes the advantages of II-VI compounds to develop chemical and optical gas and ion sensors; Describes all types of biosensors based on II-VI semiconductors and gives examples of their use in various fields.

Download or read book Physics and Chemistry of II VI Compounds written by Manuel Aven and published by . This book was released on 1967 with total page 874 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Air Force Research Resum s written by and published by . This book was released on with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Photophysical Properties of II VI Semiconductor Nanocrystals written by and published by . This book was released on 2001 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: As it is well known, semiconductor nanocrystals (also called quantum dots, QDs) are being actively pursued for use in many different types of luminescent optical materials. These materials include the active media for luminescence downconversion in artificial lighting, lasers, luminescent solar concentrators and many other applications. Chapter 1 gives general introduction of QDs, which describe the basic physical properties and optical properties. Based on the experimental spectroscopic study, a semiquantitative method-effective mass model is employed to give theoretical prediction and guide. The following chapters will talks about several topics respectively. A predictive understanding of the radiative lifetimes is therefore a starting point for the understanding of the use of QDs for these applications. Absorption intensities and radiative lifetimes are fundamental properties of any luminescent material. Meantime, achievement of high efficiency with high working temperature and heterostructure fabrication with manipulation of lattice strain are not easy and need systematic investigation. To make accurate connections between extinction coefficients and radiative recombination rates, chapter 2 will consider three closely related aspects of the size dependent spectroscopy of II-VI QDs. First, it will consider the existing literature on cadmium selenide (CdSe) QD absorption spectra and extinction coefficients. From these results and fine structure considerations Boltzmann weighted radiative lifetimes are calculated. These lifetimes are compared to values measured on very high quality CdSe and CdSe coated with zinc selenide (ZnSe) shells. Second, analogous literature data are analyzed for cadmium telluride (CdTe) nanocrystals and compared to lifetimes measured for very high quality QDs. Furthermore, studies of the absorption and excitation spectra and measured radiative lifetimes for CdTe/CdSe Type-II core/shell QDs are reported. These results are also analyzed in terms of a Boltzmann population of exciton sublevels and calculated electron and hole wave functions. Much of the absorption data and fine structure calculations are already in the literature. These results are combined with new measurements of radiative lifetimes and electron-hole overlap calculations to produce an integrated picture of the II-VI QD spectroscopic fundamentals. Finally, we adopt recent synthetic advances to make very monodisperse zincblende CdSe/CdS quantum dots having near-unity photoluminescence quantum yields (PLQYs). Due the absence of nonradiative decay pathways, accurate values of the radiative lifetimes can be obtained from time resolved PL measurements. Radiative lifetimes can also be obtained from the Einstein relations, using the static absorption spectra and the relative thermal populations in the angular momentum sublevels. One of the inputs into these calculations is the shell thickness, and it is useful to be able to determine shell thickness from spectroscopic measurements. We use an empirically corrected effective mass model to produce a "map" of exciton wavelength as a function of core size and shell thickness. These calculations use an elastic continuum model and the known lattice and elastic constants to include the effect of lattice strain on the band gap energy. Radiative lifetimes calculated both experimentally and theoretically are checked and the size dependence is compared to previous studied Type-I, II and single component particles. However, it is not enough to just understanding these basic photophysics of absorption and emission. The emission intensities (related to QYs) also change with changes of the temperature. The temperature dependent PLs of II-VI QDs is extensively studied, but most of this work is at low temperatures. Temperatures well above ambient are of interest to lighting applications and in this regime both the reversible and irreversible loss of quantum yield (thermal quenching) are serious impediments to the implementation of QDs in commercial devices. Chapter 3 will elucidate the mechanism of static thermal quenching, in which the reduction of QYs does not affect the PL decay kinetics, on CdSe, CdTe and CdSe/ZnSe QDs as a function of particle sizes/shapes, surface composition and surface ligands. Through systematic experiments, this part of the dissertation discusses several possible mechanisms (e.g. structural, activated excited state, and electronic charging) and examines which the dominant cause for loss of QY at high temperature is. The more practical step is to develop the synthetic method of highly luminescent and stable core/shell QDs with minimum thermal quenching, which greatly enhance the energy efficiency of light emitting and photovoltaic devices. As the nonradiative Auger processed are induced by surface charging described in chapter 3, static and time-resolved fluorescence and high and low power transient absorption results on CdSe/CdS and CdSe/ZnSe core/shell particles are presented in chapter 4. Two CdS shell thicknesses were examined and all of the particles had either octadecylamine (ODA) and tributylphosphine (TBP) or just ODA ligands. The results can be understood in terms of a mechanism in which there is a thermal equilibrium between electrons being in the valence band or in chalcogenide localized surface states. Thermal promotion of a valence band electron to a surface state leaves the particle core positively charged. Photon absorption when the particle is in this state results in a positive trion, which undergoes a fast Auger recombination, making the particle nonluminescent. A lack of TBP ligands results in more empty surface orbitals and therefore shifts the equilibrium toward surface trapped electrons and hence trion formation. Low- and high-power transient absorption measurements give the trion and biexciton lifetimes and the ratio of the trion to biexciton Auger lifetimes are examined and compared to the degeneracies of Auger pathways. We also study the shell thickness and composition dependence of Auger times, which is compared to the scaling factors of effective volume and electron-hole overlap considerations. Core/shell QDs often exhibit much higher luminescence quantum yields (QYs), more stability, and are depicted as having a nearly spherical core and a shell of very nearly uniform thickness, which results in a very simple picture of surface passivation. The uniformity of the shell is crucial in obtaining QDs with well passivated surfaces. However, transmission electron microscope (TEM) images disprove the ideal situation. Defects and thickness inhomogeneity in shell materials are treated qualitatively as an analog to film thickness inhomogeneity in epitaxially grown thin films. More quantitatively, the extent to which the shell thickness of core/shell particles is constant can be determined by time-resolved PL studies that measure the dynamics of hole tunneling to acceptors that are adsorbed on the shell surface due that tunneling rates varies strongly with core-acceptor separation. Careful analysis of the hole transfer kinetics reveals the extent of shell thickness inhomogeneity, however, it may be complicated by the distribution of numbers of adsorbed acceptors. All the considerations can be incorporated into a model we establish in Chapter 5 for the distribution of measured hole tunneling rates. From this analysis the distribution of shell thicknesses can be extracted from the luminescence kinetic results. This approach is therefore a sensitive measure of the distribution of tunneling distances. Thus, any defects or structural irregularities that allow the hole acceptors to adsorb closer to the particle core increases the hole tunneling rate and can be detected and quantified. A quantitative treatment of the lattice strain energy in determining the shell morphology of CdSe/CdS core/shell nanoparticles is presented in chapter 5. We use the inhomogeneity in hole tunneling rates through the shell to adsorbed hole acceptors to quantify the extent of shell thickness inhomogeneity. The results can be understood in terms of a model based on elastic continuum calculations, which indicate that the lattice strain energy depends on both core size and shell thickness. This model assumes thermodynamic equilibrium, i.e., that the shell morphology corresponds to a minimum total (lattice strain plus surface) energy. Comparison with the experimental results indicates that CdSe/CdS nanoparticles undergo an abrupt transition from smooth to rough shells when the total lattice strain energy exceeds about 27eV or the strain energy density exceeds 0.59 eV/nm2. The predictions of this model are not followed for CdSe/CdS nanoparticles when the shell is deposited at very low temperature and therefore equilibrium is not established. The effects of lattice strain on the spectroscopy and photoluminescence quantum yields of zincblende CdSe/CdS core/shell quantum dots are examined. The quantum yields are measured as a function of core size and shell thickness. High quantum yields are achieved as long as the lattice strain energy density is below ~0.85 eV/nm2, which is considerably greater than the limiting value of 0.59 eV/nm2 for thermodynamicstability of a smooth, defect free shell, as previously reported in chapter 5. Thus, core/shell quantum dots having strain energy densities between 0.59 and 0.85 eV/nm2 can have very high PL QYs, but are metastable with respect to surface defect formation. Such metastable core/shell QDs can be produced by shell deposition at comparatively low temperatures (

Download or read book Optical Properties of Semiconductor Nanocrystals written by S. V. Gaponenko and published by Cambridge University Press. This book was released on 1998-10-28 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examines the optical properties of low-dimensional semiconductor structures, a hot research area - for graduate students and researchers.

Download or read book Optical Properties of Selected II VI Semiconductor Compounds written by Yamina Lansari and published by . This book was released on 1986 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Luminescence and Lasing in II VI Semiconductors written by and published by . This book was released on 1990 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this contract was to develop a method for growth of bulk semiconducting material, suitable for monolithic infrared focal plane detectors, light emitting diodes, and laser structures. The project focused on narrow band gap HgMnTe alloys, semimagnetic semiconductors. HgMnTe is an infrared detector material with properties similar to those of HgCdTe in particular, HgMnTe electroluminescence more efficiently than HgCdTe, and p-type HgMnTe has higher conductivity than comparable p-HgCdTe; both features are advantageous in device applications.

Download or read book Semiconductors written by T. F. Connolly and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt: And often on request from the issuing installation. USAEC reports are also available from International Atomic Energy Agency Kaerntnerring A 1010 Vienna, Austria National Lending Library Boston Spa, England Monographs and reports of the National Bureau 01 Standards are for sale by Superintendent of Documents U.S. Government Printing Office Washington, D.C. 20402 Theses, listed as Dissertation Abstracts + number, are available in North and South America from University Microfilms Dissertation Copies P.O. Box 1764 Ann Arbor, Michigan 48106 and elsewhere from University Microfilms, Ltd. St. John's Road Tylers Green Penn, Buckinghamshire England Conlenls Addendum ... xiii 1. Information Centers and Other Services ... 1 2. Journals ... 3 3. Methods of Crystal Growth - Books and Reviews ... 5 4. Semiconductors - General, Reviews, and Bibliographies ... 11 5. 1-V -VI Compounds ... 21 6. li-IV - V2 Compounds ... 23 7. II - V Compounds ... 29 a. General, Reviews, and Bibliographies ... 29 b. Zinc Compounds ... 30 1. Zn3P2" .. . .. . .. . . .. ... .. ... . .. ... . . .. ... .. . . 30 2. ZnAs ... 30 3. ZnSb ... 30 4. Zn Mixed Systems ... 31 c. Cadmium Compounds ... 31 31 1. Cd3P2' ... 2. Cd3As2 ... 31 3. CdSb, Cd3Sb2 ... 33 37 8. li-VI Compounds ... a. General, Reviews, and Bibliographies ... ... 37 ... b. Zinc Compounds ... . ... ... 39 ... 1. ZnO ... 39 Preparation and Properties ... 39 Electrical Properties ... ... 41 ... Optical Properties ... ... 45 ... Physical Properties and Structure ... ... 47 ... 2. ZnS ... 49 3. ZnSe ... 52 4. ZnTe ... ' ... 54 5. Zn Mixed Systems. ... ... 55 ... 55 c. Cadmium Compounds ... 55 1. CdS ... 2. CdSe ... 60 3. CdTe ... 61 4. CdTernaries ... ... 62 ... d. Mercury Compounds ... ... . 64 ...

Download or read book II VI Compounds written by Brian Ray and published by Elsevier. This book was released on 2013-10-22 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: II-VI Compounds covers the general idea of the way in which II-VI compounds behave. The book describes the fundamental nature of II-VI compounds; the preparation and single crystal growth; and the fundamental optical properties of II-VI compounds. The text also discusses the luminescence; the photo conductivity and associated behavior; the transport properties; and the applications of II-VI compounds. Students taking materials science or engineering courses will find the book useful.

Download or read book Porous Silicon From Formation to Applications Optoelectronics Microelectronics and Energy Technology Applications Volume Three written by Ghenadii Korotcenkov and published by CRC Press. This book was released on 2016-01-06 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt: Porous silicon is rapidly attracting increasing interest from various fields, including optoelectronics, microelectronics, photonics, medicine, sensor and energy technologies, chemistry, and biosensing. This nanostructured and biodegradable material has a range of unique properties that make it ideal for many applications. This book, the third of a