Semiconductor Science Research Articles

Crystal structure and electronic properties of the new structure dinitride–nitride N2MN (M: Cu, Ag)

AbstractCopper and nitrogen compounds and silver and nitrogen compounds have been researched with the first‐principle linear combination of the atomic orbitals in full‐screen basis with the local gradient and hybrid potential of the density functional theory (DFT) realized in the CRYSTAL09 program code. We have found the structural N2MN (M: Cu, Ag) dinitride–nitride phase having an orthorhombic structure, the spatial group of the Ibam symmetry and four formula units in the primitive cell that have not been reported before. The structure was found to be layered, the metal atoms are linearly circled by the nitride N atoms, whereas, the other two atoms make a molecule with a small negative charge of ∼0.02 e. The volume elastic modules in N2CuN, N2AgN crystals are equal to 4.3 and 6.6 GPa, respectively, and their pressure derivatives are equal to 6.7 and 5.3, respectively. The electron energy spectrum makes a superposition of weakly interacting molecular states of N2 and metal states of MN. The bandgap width equals ∼0.05 eV. The estimations of the enthalpy energies show that N2MN possess large energy content and in its decomposition into metal and gaseous nitride the energy release can reach 8 eV cell−1, which appears to be higher than that in the known metal azides. Thus, the new structure of the dinitride–nitride N2MN combines the properties of molecular and semiconductor crystals: high compressibility, strong mechanical anisotropy, localized vacant states in the zone spectrum, and small bandgap. The unique physical properties can ensure their application as energy materials, the source of chemically pure nitride, and in semiconductor and optical material science.

Dps biomineralizing proteins: multifunctional architects of nature

Dps proteins are the structural relatives of bacterioferritins and ferritins ubiquitously present in the bacterial and archaeal kingdoms. The ball-shaped enzymes play important roles in the detoxification of ROS (reactive oxygen species), in iron scavenging to prevent Fenton reactions and in the mechanical protection of DNA. Detoxification of ROS and iron chaperoning represent the most archetypical functions of dodecameric Dps enzymes. Recent crystallographic studies of these dodecameric complexes have unravelled species-dependent mechanisms of iron uptake into the hollow spheres. Subsequent functions in iron oxidation at ferroxidase centres are highly conserved among bacteria. Final nucleation of iron as iron oxide nanoparticles has been demonstrated to originate at acidic residues located on the inner surface. Some Dps enzymes are also implicated in newly observed catalytic functions related to the formation of molecules playing roles in bacterium-host cell communication. Most recently, Dps complexes are attracting attention in semiconductor science as biomimetic tools for the technical production of the smallest metal-based quantum nanodots used in nanotechnological approaches, such as memory storage or solar cell development.

Special Issue: Advanced Electron Microscopy for Catalysis

Catalysis plays a key role for the sustainable development of our society. The characterization of morphology, chemical composition, surface, and internal structure of catalysts is of great importance for the synthesis of materials of high selectivity, high conversion rate, with long cycle times favored for their reduced environmental impact. Modern electron microscopy with its arsenal of imaging and spectroscopic techniques gives access to the collective and individual properties of such materials. From the very beginning of electron microscopy, its potential to reveal the microscopic details of catalysts has been explored. In 1940, M. von Ardenne and D. Beischer published in Angewandte Chemie possibly the first paper to describe the usefulness of transmission electron microscopy (TEM) for extracting morphological and structural information on supported and unsupported catalysts.1 J. Turkevich reported in 1945 the use of the electron microscope for the study of several important catalysts.2 Catalysis, together with the materials science of semiconductors, have been the driving force for the continuous improvement of electron optics and microscopic design for transmission electron microscopes. Not to forget, is Crewe’s pioneering development of the annular dark field scanning transmission electron microscopy (STEM) technique revealing single or small clusters of heavy atoms as bright features against the low intensity level of their supports.3 Advanced electron microscopes are not only marked by their high resolution, they are also defined by their high brightness field emission gun with its highly coherent electron beam. Aberration correction significantly improves the quality of high-resolution images by eliminating the Frensel fringes and delocalization effects, so that the surface structure of industrial catalysts can be determined (see the example in Figure 1).4, 5 The implementation of monochromators, and the development of high resolution electron-energy loss spectrometery (EELS), mark a new generation of analytical electron miscroscopy. Modern, advanced, analytical electron microscopes with aberration correctors provide genuine atomic and energy resolution and high sensitivity to heavy or light atoms.6 EELS, by using a monochromatized beam, is able to measure the core-Level near-edge structure in loss spectra with an energy resolution that is comparable to that measured with a synchrotron.7 Element mapping, a technique that provides a 2D image of inhomogeously distributed multi-components catalyst, is a well-established technique, used not only by catalytic researchers, but also other materials scientists, an example of which is illustrated in Figure 2. A newly developed windowless X-ray energy-dispersive spectrometer (XEDS) based on silicon drift detector technology8 allows a high speed recording of energy-dispersive spectrum and element mapping, down from hours to minutes, even at nanoscales. The combination of element mapping with electron tomography, a technique that is widely used by biologists, can give a truly 3D distribution of the active sites/phase of supported or mixed catalysts. In situ or environmental transmission electron microscopy allows for the first time the visualization of chemical/physical processes at atomic resolution. Advanced electron microscopy comes out from the shadow of being a “passive” characterization tool to become an active research method in materials and in catalysis. a) An experimental high-resolution image of the surface of an Ag catalyst used for the hydrogenation of acrolein. b) The structural model obtained from DFT calculations showing the position of α- and γ-oxygen on Ag. c) A simulated high-resolution image using the structure model in b. For more details, see Ref. [4]. Element mapping of an inhomogeously distributed multi-component catalyst. Advanced electron microscopy generates more realistic views of catalysts, allowing optimization of their structure to improve their performance. Presentations at the 1st International Symposium on Advanced Electron Microscopy for Catalysis and Energy Storage Materials at the Fritz-Haber Institute in Berlin provided a fascinating snapshot of the latest developments in catalyst microscopy. Aberration-corrected microscopes, cryo-tomography, and specialty heating stages are shedding new light on the nanoworld of catalysts and are beginning to facilitate improvements in catalyst design.9 This Special Issue contains selected papers presented at this symposium. Since then, other new developments in electron microscopy have emerged. By using photons as input rather than as an output signal, particularly in the form of femtosecond pulses, Zewail and colleagues developed ultrafast microscopy.10–12 The production of vortex electron beam in an electron microscope is exciting.13 The applications of direct relevance in catalysis are still to be identified, the potential could be tremendous.14 1

(Invited) Remembering Ulrich Gösele

Prof. Dr. Ulrich M. Gösele died unexpectedly and far too early in Nov. 2009. He would certainly have participated in several ses-sions of this meeting; his untimely death deprived us of that pleasure. Prof. Ulrich Gösele was an outstanding scientist with a distinguished record in many fields, including porous semicon-ductor science and technology. In this contribution for "Pits and Pores" a personal account of his life is given, based not only on scientific collaboration but also on a longstanding friendship. He will be remembered not only for his outstanding contributions to science but also as a reliable and witty friend and a highly motivating mentor.

Tungsten and other heavy metal contamination in aquatic environments receiving wastewater from semiconductor manufacturing

Through analyses of water and sediments, we investigate tungsten and 14 other heavy metals in a stream receiving treated effluents from a semiconductor manufacturer-clustered science park in Taiwan. Treated effluents account for ∼50% of total annual river discharge and <1% of total sediment discharge. Dissolved tungsten concentrations in the effluents abnormally reach 400 μg/L, as compared to the world river average concentration of <0.1 μg/L. Particulate tungsten concentrations are up to 300 μg/g in suspended and deposited sediments, and the corresponding enrichment factors are three orders of magnitude higher than average crust composition. Surprisingly, the estimated amount of tungsten exported to the adjacent ocean is 23.5 t/yr, which can approximate the amount from the Yangtze River should it be unpolluted. This study highlights the urgency of investigating the biological effect of such contamination.

Preface: Phys. Status Solidi C 8/2

AbstractThe present issue of physica status solidi contains the papers presented at the 37th International Symposium on Compound Semiconductors (ISCS 2010). The symposium was held in Takamatsu, Kagawa, Japan, May 31–June 4, 2010. This symposium was one in an annual series that is held throughout North America, Europe and Asia. The last three conferences were held in Santa Barbara, USA (2009), Rust, Germany (2008) and Kyoto, Japan (2007).The symposium, which began in 1966 under the name “International Symposium on GaAs and Related Compounds” has a long standing tradition in science, technology, and applications of compound semiconductors. At the 2010 conference, 11 subcommittees (Growth and Nanostructure Formation; Electron Devices; Photonic Devices; New Properties and Physics; Spintronics; Nanocharacterization and Nanodevices; GaN and Related Semiconductors; Oxide Semiconductors; Carbon Related Materials; Organic Semiconductors and Other Soft Materials; Solar Cells) covered the entire spectrum of III–V compound semiconductors as well as II–VI, oxide semiconductors, and carbon related materials.The symposium was first collocated with the International Conference on Indium Phosphide and Related Materials (IPRM 2010) as “Compound Semiconductor Week 2010”. The ISCS and IPRM conferences attracted about 670 participants in total and the ISCS 2010 attended by 462 registered participants from more than 22 countries all over the world. Over the course of the symposium, 3 general plenary talks (conducted with IPRM), 3 plenary talks, 41 invited papers, 22 late news papers as well as 368 contributed papers were given as oral or poster presentations. The ISCS 2010 highlighted emerging wide‐band gap and oxide semiconductor materials and devices as well as high‐speed electronics, next generation photonics, and physics studies based on traditional compound semiconductors. The importance of the green application of compound semiconductors was also well addressed.The symposium is also the venue for the attribution of three prestigious scientific awards, the Welker Award, the Quantum Device Award and the Young Scientist Award.The Proceedings contains many of the papers presented at the symposium.We would like to thank all the participants of the ISCS 2010 for contributing to the success of the symposium and acknowledge the diligent work of the committee members and referees of the manuscripts.We would also like to thank Prof. Hiroshi Itoh and other members of Kagawa University for their excellent local organization. Takamatsu, a beautiful city facing an inland sea called “Setonaikai”, has Japanese style gardens, local culture, and the delicious Japanese noodle “Udon”, giving us the ideal location to combine a scientific conference with motivating entertainment.The 38th International Symposium on Compound Semiconductors, organized by Prof. Oliver Ambacher will be held at Berlin, Germany, May 22–26, 2011.January 2011

Materials science perspectives for oxide ferromagnetic semiconductors

The prospects for the development of the materials science of oxide semiconductors maintaining a spin orientation of the charge carriers above room temperatures are considered. The problems that need to be solved upon the transition from synthesized macroceramics to microelements of spin electronics are analyzed.

Eighth International Workshop on Epitaxial Semiconductors on Patterned Substrates and Novel Index Surfaces

This year, Italy hosted the VIII ESPS-NIS workshop. It was organized by the L-NESS Inter-University Laboratory (Politecnico di Milano and Universita di Milano Bicocca) in Como (Italy) under the auspices of Prof. Leo Miglio. The program of 10 invited speakers, 30 contributed and numerous posters covered a wide range of topics, all connected with the study of substrate patterning and high index substrate influence on the growth and the control of semiconductor nanostructures. Presentation was given on novel patterning techniques, both top-down and bottom-up, and the effect of patterning on self-organized dots and wires. In particular, wires have recently attracted a wide attention, since they are important both in fundamental physics and in advanced electronics and photonics applications. New concept bottom-up patterning techniques, like metallic droplet nano-drilling and droplet epitaxy local artificial substrates, were presented. Epitaxy of graphene on patterned substrates was also a topic of the workshop. The possibility of controlling, by substrate patterning, the nucleation site and the strain relaxation of self-organized Stranski–Krastanow dots in Ge/Si and InAs/GaAs systems has motivated a strong effort as evidenced by the number and the quality of the contribution presented. Some very interesting features involve strain engineering, position and size control, defectivity reduction. In addition, patterned substrates epitaxy inevitably involves growth on high index planes, which stimulated the understanding the effects of epitaxial growth of semiconductors on non-(100) surfaces. The ESPS-NIS meeting discussed all these aspects, which include material growth, characterization, theory and device topics related to patterned substrates, novel index substrates and low dimensional structures. Once more the meeting achieved its aim of being a forum for lively discussion of up to date work, allowing the interaction of specialist of different fields of semiconductor science and technology put together by the common interest in the effects of patterning and surface orientation on nanostructure fabrication. The vast potential of interrelation of nanotechnology, patterning and surface science was highlighted. The organizing committee would like to thank the speakers for their considerable efforts in making this workshop a success. A fundamental role in the organization was also played by the personnel of the the Centro di Cultura Scientifica Alessandro Volta of Como. Finally, special thanks are due to the University of Milano Bicocca and the Politecnico di Milano, Polo di Como whose sponsorship made this international workshop possible. ESPS-NIS VIII Conference Chair: Prof. Leo Miglio (University of Milano Bicocca) Program committee: Chair: Prof. Stefano Sanguinetti (University of Milano Bicocca) Dr Francesco Montalenti (University of Milano Bicocca) Dr Roman Sordan (Politecnico di Milano) Dr Daniel Chrastina (Politecnico di Milano) Local organizing Committee Dr Giovanni Isella (Politecnico di Milano) Dr Emiliano Bonera (University of Milano Bicocca) Dr Monica Bollani (CNR—Milano) Dr Alessandra Cazzaniga (Centro Volta)

Silver(I)-(poly)chalcogenide Halides – Ion and Electron High Potentials

Abstract Materials with high dynamics in the solid state are of potential interest in semiconductor science and for a great variety of energy applications. In most of the cases the majority of physical properties of such compounds are directly related to their electronic structure. Optimization of properties is therefore correlated with direct or indirect control of this parameter. Compounds with highly mobile ions like the coinage metal cations and the heavy chalcogenide anions can easily be modified chemically or physically to fine tune their electronic structures. The range of adjustable properties lasts from ion conductivity, magneto resistance, thermoelectricity to a reversible redox-driven switch of semiconductivity. Today, the strong demand on clean energy production, the efficient energy transport and energy storage is a major goal for present and oncoming generations. Stable, mixed-conducting materials will play a major role in this process. The ongoing development of coinage metal chalcogenide halides during the last 50 years reflects the fundamental interest in this field. Many interesting and sometimes unexpected properties have been determined recently which substantiates the great potential of this class of materials. Especially the new class of coinage metal polychalcogenide halides is of potential interest due to their drastic modulations of physical properties driven by a fundamental tuning of its electronic structures. Thermopower and thermal diffusivity, two major properties to tune thermoelectricity can be varied in such a way that drastic changes can be addressed in very small temperature ranges close to room temperature. Herein we report on the recent progress of polychalcogenide and chalcogenide halides with the mobile d 10 ions Ag and Cu putting the main focus on silver compounds.

New approach to cathodoluminescence studies in application to InGaN/GaN laser diode degradation

Cathodoluminescence (CL) studies are widely applied in semi-conductor science and technology. However, for structures with a p-n junction the CL spatial distribution can be strongly affected by internal current flows of the electron beam induced current generated within the structure. This influence is the investigated in application to CL studies of degradation in aged laser diodes with InGaN multiquantum wells.

Back Cover (Phys. Status Solidi B 8/2009)

physica status solidi (b)Volume 246, Issue 8 Back Cover Back Cover (Phys. Status Solidi B 8/2009) First published: 27 July 2009 https://doi.org/10.1002/pssb.200990011AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract In the 1950s, when most semiconductor scientists concentrated their efforts on silicon and germanium and when binary semiconductors were still at the laboratory stage, Boris Timofeevich Kolomiets (1908–1989) found ternary semiconductors far more challenging. Pursuing his efforts to investigate amorphous semiconductors at the Ioffe institute – its main building is shown on the back cover – he can be considered the founding father of this research field. This issue which is guest-edited by Alexander V. Kolobov, AIST, Japan, contains papers written by scientists who have made significant contributions to the science and technology of amorphous semiconductors. The articles are dedicated in memoriam to Professor Kolomiets in recognition of his scientific achievements and for his accomplishments as a former board member of this journal. Volume246, Issue8August 2009 RelatedInformation

Information for authors: Phys. Status Solidi C 6/7

physica status solidi cVolume 6, Issue 7 p. 1790-1791 Information for authors Information for authors: Phys. Status Solidi C 6/7 First published: 12 June 2009 https://doi.org/10.1002/pssc.200960065AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume6, Issue7Special Issue: 6th International Conference on Porous Semiconductor Science and Technology (PSST 2008)July 2009Pages 1790-1791 RelatedInformation

Preface: Phys. Status Solidi A 206/2

The Seventh International Symposium on Semiconductor Light Emitting Devices (ISSLED 2008) was held in Phoenix, Arizona, on the week of 27 April to 2 May 2008. This Symposium is a new edition of the International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED) series which has been held biannually to provide a platform for scientists and engineers to discuss progress and future trends in the rapidly advancing wide band gap semiconductor science and technologies and their applications into visible and ultraviolet light emitting diodes and diode lasers. The first symposium in the series was organized by Prof. Akihiko Yoshikawa and was held in Chiba, Japan, in 1996. The following symposia were held in Chiba, Japan, in 1998; Berlin, Germany, in 2000; Cordoba, Spain, in 2002; Geongju, Korea, in 2004; and more recently in Montpellier, France, in 2006. The participants were 33 from Asia (16 from Japan), 19 from Europe, and 66 from North America. The ISSLED 2008 scientific program included a total of 14 invited talks and 63 contributed talks. This symposium covered materials and their devices based on GaN, ZnSe, and ZnO semiconductors. The topics included materials growth and characterization, optoelectronic properties, device design and fabrication, white light emitting diodes, ultraviolet emitters and detectors, photonics, device performance and reliability, novel optoelectronic devices and applications, spintronics, and biological applications. The next meeting in this series was proposed, and accepted by the International Advisory Committee, to be held in China, in May 2010, to be organized by Prof. Guoyi Zhang of Peking University (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Mapping of Conduction Band Dispersions in AlAs 2D X-States

Mapping of Conduction Band Dispersions in AlAs 2D X-States Yongmin Kim, Kyooho Jung and Hyunsik Im Department of Semiconductor Science, Dongguk University, Seoul 100-715 (Received 8 October 2008) Conduction band dispersions of 2-dimensional (2D) AlAs near the X-point are mapped using 2D!2D resonant tunneling in the presence of magnetic elds perpendicular to the tunneling current. The eld-dependent resonance bias shift signi es the features of the in-plane dispersion relation of the collector quantum well. The dynamics of magneto-tunneling is demonstrated to be sensitive to the in-plane dispersions of the emitter and the collector wells and to the sample's structure. PACS numbers: 73.40.G, 73.61.E, 42.50.M

The materials science of semiconductors

The materials science of semiconductors

Vitali Parkhutik - His Contributions to Porous Semiconductor Science andTtechnology Over 30 years

not Available.

Preface: phys. stat. sol. (c) 5/9

AbstractThe present issue of physica status solidi (c) contains the papers presented at the 34th International Symposium on Compound Semiconductors (ISCS‐2007). The symposium was held in Kyoto, Japan, 15–18 October 2007. This conference was one of the annual series, which rotates between America, Europe and Asia. The last three conferences were held in Vancouver, Canada (2006), Rust, Germany (2005) and Seoul, Korea (2004).The symposium, whose history goes back to 1966 under the name “International Symposium on GaAs and Related Compounds” has a long standing tradition in science, technology, and applications of compound semiconductors. In this conference, 11 subcommittees (Growth and Nanostructure Formation; Transport Devices; Photonic Devices; Physics; Spintronics; Characterization, Nanoprobe and Nanomechanics; GaN and Related Semiconductors; Oxide Semiconductors; SiGe and Related Semiconductors; Carbon Related Materials; Organic Semiconductors and Other Soft Materials) cover the entire spectrum of III–V compound semiconductors as well as II–VI, SiGe, oxide semiconductors and carbon related materials.The symposium was attended by 550 registered participants from more than 25 countries all over the world. During the course of the symposium, 4 plenary talks, 27 invited papers, 7 late news papers as well as 295 contributed papers were given as oral or poster presentation. ISCS‐2007 highlighted emerging wide‐band gap and oxide semiconductor materials and devices as well as high‐speed electronics, next‐generation photonics and physics studies based on the traditional compound semiconductors.The symposium is also the venue for the attribution of three prestigious scientific awards, the Welker Award, the Quantum Device Award and the Young Scientist Award.The Proceedings contain many papers presented at the conference. The chapters are organized in a way that related papers are grouped by the subjects of the subcommittees.We would like to thank all the participants of ISCS‐2007 for contributing to the success of the symposium and acknowledge the diligent work of the committee members and referees of the manuscripts. We also thank Prof. Shizuo Fujita, Kyoto University, for the excellent local organization. Kyoto, the ancient capital of Japan with more than one thousand years of history, is full of beautiful temples, shrines, and gardens, giving us an ideal location to combine a scientific conference with motivating entertainment. Finally, we extend our thanks to Ms. Kaori Yoshida for her excellent secretary job for these proceedings.The 35th International Symposium on Compound Semiconductors, organized by Prof. Günter Weimann and Prof. Oliver Ambacher will be held at Euro‐Park, Rust near Freiburg, Germany, 21–24 September 2008.May 2008

The future of solar photovoltaics: A new challenge for chemical physics

Abstract In recent times, photovoltaic (PV) technologies for solar energy conversion have gained greater recognition. World production of PV cells and modules over the last five years grew at an average of around 40 % a year. The history of modern PV science started more than half a century ago. However, the period that followed exploited the mid-20th century developments in the basics of solid-state physics and semiconductor science. With only a few exceptions, almost no major achievements were attained during a long period of time. The present paper offers an attempt of a critical retrospective look at the history and current progress of solar PV research from a personal viewpoint. It also addresses the current status of research on conventional solid-state PV devices and compares it with the alternative organic and molecular PV systems. The paper briefly describes the potential of new types of organic and mesoscopic dye-sensitized solar cells (DSCs). The paper shows that chemical physics rather than traditional solid-state physics is expected to lead to exciting challenges in the future of PV science.

Relaxation time limits problem for hydrodynamic models in semiconductor science

In this article, two relaxation time limits, namely, the momentum relaxation time limit and the energy relaxation time limit are considered. By the compactness argument, it is obtained that the smooth solutions of the multidimensional nonisentropic Euler–Poisson problem converge to the solutions of an energy transport model or a drift diffusion model, respectively, with respect to different time scales.

Study on a Cross Diffusion Parabolic System

This paper considers a kind of strongly coupled cross diffusion parabolic system, which can be used as the multi-dimensional Lyumkis energy transport model in semiconductor science. The global existence and large time behavior are obtained for smooth solution to the initial boundary value problem. When the initial data are a small perturbation of an isothermal stationary solution, the smooth solution of the problem under the insulating boundary condition, converges to that stationary solution exponentially fast as time goes to infinity.