Structural and optical properties of iivi and iiiv. Using allelectron selfconsistent electronic structure techniques, we study their effects on valence properties. Yet, they can be compared with the iiiv semiconductors gaasinp for their band gap engineering facilities. These semiconductors crystallize either in the zincblende lattice structure. Molecular beam epitaxy mbe has proven to be a powerful technique for the elaboration of high. The efficiency of nanocrystal ncbased devices is often limited by the presence of surface states that lead to localized energy levels in the bandgap. Isothermal close space sublimation for iivi semiconductor. Pressure dependence of energy gap of iiiv and iivi. Phase diagram determination of ii vi semiconductors. Pl spectroscopy is a sensitive, nondestructive technique that can provide information on the type and distribution of defects andor impurities in a semiconductor and has been used to examine the bulk quality of ii vi crystals 3. Ii vi semiconductor materials and their applications deals with ii vi compound semiconductors and the status of the two areas of current optoelectronics applications.
Among the group iivi semiconductors, pure and alloyed cadmium telluride cdte films have been the most vigorously investigated. In this paper, we will show that anion vacancies in iivi and cuiiivi 2 compounds can exhibit both type and behavior. Wurzite iiivs and iivis lead salts ivvis, column iv material semiconductor crystal lattice energy band system name symbol structure perioda gapev type iiiv aluminum nitride aln w a, c 6. In this paper, we will show that anion vacancies in ii vi and cuiii vi 2 compounds can exhibit both type and behavior. Semiconductor iivi quantum dots with interface states and. Ii vi leverages its gallium arsenide technology platform for a broad portfolio of semiconductor laser products with a wide range of applications in various end markets. Optical properties study of ii vi semiconductors nps prepared by laser ablation in liquid technique lamis faaz nassir abstract. For ii vi semiconductors, we find that pd repulsion and hybridization i lower the band gaps, ii alter the sign of the crystalfield splitting, iii reduce the spinorbit splitting, iv change the valence band offset between commonanion semiconductors, and v increase the equilibrium lattice parameters, pd repulsion is also shown to be. Although theoretical modeling has greatly improved our comprehension of the nc surface, several experimental studies suggest the existence of metalbased traps.
Ii vi semiconductor compounds are compounds composed of a metal from either group 2 or 12 of the periodic table the alkaline earth metals and group 12 elements, formerly called groups iia and iib and a nonmetal from group 16 the chalcogens, formerly called group vi. A companion volume to ternary alloys based on iivi semiconductor compounds crc press, 20 and quaternary alloys based on iivi semiconductor compounds crc press, 2014, multinary alloys based on iivi semiconductors provides uptodate experimental and theoretical information on phase relations based on iivi semiconductor systems with five or more components. Calculated natural band offsets of all iivi and iiiv. One of the most studied compound semiconductors after gallium arsenide, znse forms the centerpiece of a family of iivi semiconductors such as cdse, zns, and mgse fig. Though, these calculations are effective for certain substances, but are ineffective in the calculations of the band structures of the highly correlated electron systems, with d or f orbital like iivi compounds. Chelikowsky, in comprehensive semiconductor science and technology, 2011. The iivi semiconductors znx vi, cdx vi, and hgx vi are known to have a metal d band inside the main valence band. Changes in thermodynamic stability due to interfacial atomic exchange in heterovalent superlattices the total energy consists of. Nanocrystals of group iivi semiconductors, known as quantum dots qds, in which electrons and holes are three dimensionally confined within the exciton bohr radius of the material, are characterized by the exceptional optical properties, such as broad absorption and sharp emission bands as well as sizetunable photoluminescence in the visible spectral range. By this approach, a wide variety of core materials could be. The handbook contain important information about a large number of. The system uses an 8 diameter lapping wheel combined with abrasive suspension or polishing cloth to produce a lapped, smooth surface. Most semiconductors are formed from elements from groups ii, iii, vi, v, vi of the periodic table.
Pl spectroscopy is a sensitive, nondestructive technique that can provide information on the type and distribution of defects andor impurities in a semiconductor and has been used to examine the bulk quality of iivi crystals 3. Properties of groupiv, iiiv and iivi semiconductors wiley. Accurate theoretical bandgap calculations of iivi semiconductors. Specifically, the growth, charactrtization, materials and device issues for these two applications are described. Optical properties study of iivi semiconductors nps prepared. Isaac hernandezcalderon, in molecular beam epitaxy, 20. Properties of the iivi compound semic0nductors author d. The use off laser ablation to generate nanoparticle of a solid target in a liquid environment is an fast, easy and green method to product a large scale of nanomaterials with tailored properties. Iivi ternary alloy semiconductors cadmium zinc telluride cdznte, czt mercury cadmium telluride hgcdte mercury zinc telluride hgznte cadmium selenide cdse is a solid, binary compound of cadmium and selenium. Structural and optical properties of ii vi and iiiv compound semiconductors by jingyi huang a dissertation presented in partial fulfillment of the requirements for the degree doctor of philosophy approved april 20 by the graduate supervisory committee. Band structure to study the dos of iivi scs, the initial step is the band structure calculation of the bulk semiconductors using the multiband k. Lecture 1 introduction to semiconductors and semiconductor. Common names for this compound are cadmiumii selenide, cadmium selenide, and cadmoselite a very rare mineral.
In addition, iivi laser enterprise manufactures pump lasers for optical amplifiers for both terrestrial and submarine. The prototypical iivi semiconductor is zinc selenide. Quaternary alloys based on ii vi semiconductors crc. Optical properties study of iivi semiconductors nps prepared by laser ablation in liquid technique lamis faaz nassir abstract. Pdf muonium in nanocrystalline iivi semiconductors.
Properties of the ii vi compound semic0nductors author d. Pdf muonium in nanocrystalline iivi semiconductors rui. The book illustrates uptodate experimental and theoretical information about phase relations based on iivi. Iivi compounds form a particulary class of semiconductor materials owing to their specific physical properties. Role of surface reduction in the formation of traps in n. Specifically, the growth, charactrtization, materials and device. The iivi semiconductors have been extensively studied due to their effective use in. Assume a compound semiconductor has 25% atomic concentrations of ga, 25% atomic in and 50% atomic of n. Ii vi ternary alloy semiconductors cadmium zinc telluride cdznte, czt mercury cadmium telluride hgcdte mercury zinc telluride hgznte cadmium selenide cdse is a solid, binary compound of cadmium and selenium. Intrinsic ntype, difficult to dope ptype, but can be ptype doped with nitrogen. Applications laboratory report 83 lapping and polishing ii vi semiconductors. Iivi semiconductor an overview sciencedirect topics.
Purchase iivi semiconductor bluegreen light emitters, volume 44 1st edition. Wurtzite structure semiconductors many ii vi compounds like zns occur in both the wurtzite and zincblende structures. We report a general synthetic approach to tetrapodshaped colloidal nanocrystals made of various combinations of ii. Isothermal close space sublimation for iivi semiconductor filling of porous matrices, nanoscale research letters, 2012, pp. Ivs, iiivs, iivis, iviis these compound iiiv semiconductors are a subset of the universe of simple anb8n binary octet. For iivi semiconductors, we find that pd repulsion and hybridization i lower the band gaps, ii alter the sign of the crystalfield splitting, iii reduce the. The grain size and crystallinity of cdte thin film grown from a nanoparticle precursor was examined by pehnt et al. Iviv, iiiv, or iivi combinations leading to the above reduced semiconductor notation. Pdf phase diagram determination of iivi semiconductors. Unlike other ii vi semiconductors, z nte always contains anion te excess 156, which makes it intrinsically a p type semiconductor. Iivi semiconductor materials, devices, and applications. Pressure dependence of energy gap of iiiv and iivi ternary semiconductors dongguo chen n. Growth of wide band gap iivi compound semiconductors by.
The handbook contain important information about a large number of semiconductors. Investigation of subsurface damage of iivi semiconductors. Many methods have been extensively applied to grow highquality. Iivi laser enterprise gmbh is an industryleading manufacturer of highpower semiconductor laser components enabling fiber and direct diode laser systems for material processing, medical, consumer and printing applications. Nonlinear variations in the electronic structure of iivi and iiiv wurtzite semiconductors with biaxial strain appl. Iivi semiconductors have demonstrated convenient properties for application in photodetectors, solar cells, lightemitting diodes, laser diodes, solar blind detectors, radiation detectors, magnetooptical devices, biophotonics, etc. Anion vacancies as a source of persistent photoconductivity. Structural and optical properties of iivi and iiiv compound semiconductors by jingyi huang a dissertation presented in partial fulfillment of the requirements for the degree doctor of philosophy approved april 20 by the graduate supervisory committee.
Iivi semiconductor bluegreen light emitters, volume 44. Infrared photodiodes on iivi and iiiv narrowgap semiconductors. Data handbook contains frequently used data from the corresponding larger landoltbornstein handbooks in a low price book for the individual scientist working in the laboratory. Iivi semiconductor materials and their applications deals with iivi compound semiconductors and the status of the two areas of current optoelectronics applications. Iivi semiconductor materials and their applications crc. Article pdf available in applied physics letters 6020. Ii vi s highpower laser modules are used to energize. For instance, the most important advantage of hgcdte ternary alloy is ability to tune its energy band gap in wide range. Ii vi semiconductors have demonstrated convenient properties for application in photodetectors, solar cells, lightemitting diodes, laser diodes, solar blind detectors, radiation detectors, magnetooptical devices, biophotonics, etc. Common names for this compound are cadmium ii selenide, cadmium selenide, and cadmoselite a very rare mineral.
Quaternary alloys based on iivi semiconductors consolidates data pertaining to diagrams of quaternary systems based on these semiconductor compounds. Pdf properties of groupiv, iiiv and iivi semiconductors. Optical properties study of iivi semiconductors nps. The spectral cutoff of hgcdte photodiodes can be tailored by adjusting the hgcdte alloy composition over the mm range. Almost all the semiconductors of practical interest are the groupiv, iiiv and iivi semiconductors and the range of technical applications of such semiconductors is extremely wide. Growth and properties widebandgap iivi compounds are been applied to optoelectronic devices, especially lightemitting devices in the shortwavelength region of visible light, because of their direct gap and suitable bandgap energies. Applications laboratory report 83 lapping and polishing iivi semiconductors. Structural and optical properties of iivi and iiiv compound. Isothermal close space sublimation for ii vi semiconductor filling of porous matrices, nanoscale research letters, 2012, pp. A firstprinciples prediction article pdf available in phys rev b. Basic interfacial physics of iiiviivi heterovalent superlattices 2. The model 920 lapping and polishing machine is shown with the model 92002 workstation and the model 147d lapping and polishing fixture. Uniform tetrapods were prepared using preformed seeds in the sphalerite structure, onto which arms were grown by coinjection of the seeds and chemical precursors into a hot mixture of surfactants.
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