M. A. S. Kalceff

Bio: M. A. S. Kalceff is an academic researcher. The author has contributed to research in topics: Cathodoluminescence & Quantum well. The author has an hindex of 1, co-authored 2 publications receiving 281 citations.

V-grooved GaAs/AlGaAs quantum wires with side wall quantum wells intermixed by pulsed anodization and rapid thermal annealing

Abstract: A novel impurity-free interdiffusion (IFID) technique, namely, pulsed anodization and subsequent rapid thermal annealing, is applied to study GaAs/AlGaAs multiple quantum wires grown by metalorganic chemical vapour deposition on V-grooved GaAs substrates. Photoluminescence (PL) and cathodoluminescence (CL) emissions are observed from GaAs quantum wires. IFID increases both carrier confinement in quantum wires and the efficiency of excess carrier transfer from sidewall quantum wells to quantum wires, where the excess carriers are generated either by optical pumping (PL) or electron pumping (CL).

Origin, spectral characteristics and practical applications of the cathodoluminescence (CL) of quartz – a review

Abstract: Investigations of natural and synthetic quartz specimens by cathodoluminescence (CL) microscopy and spectroscopy, electron paramagnetic resonance (EPR) and trace-element analysis showed that various luminescence colours and emission bands can be ascribed to different intrinsic and extrinsic defects. The perceived visible luminescence colours in quartz depend on the relative intensities of the dominant emission bands between 380 and 700 nm. Some of the CL emissions of quartz from the UV to the yellow spectral region (175 nm, 290 nm, 340 nm, 420 nm, 450 nm, 580 nm) can be related to intrinsic lattice defects. Extrinsic defects such as the alkali (or hydrogen)-compensated [AlO4/M+] centre have been suggested as being responsible for the transient emission band at 380–390 nm and the short-lived blue-green CL centered around 500 nm. CL emissions between 620 and 650 nm in the red spectral region are attributed to the nonbridging oxygen hole centre (NBOHC) with several precursors. The weak but highly variable CL colours and emission spectra of quartz can be related to genetic conditions of quartz formation. Hence, both luminescence microscopy and spectroscopy can be used widely in various applications in geosciences and techniques. One of the most important fields of application of quartz CL is the ability to reveal internal structures, growth zoning and lattice defects in quartz crystals not discernible by means of other analytical techniques. Other fields of investigations are the modal analysis of rocks, the provenance evaluation of clastic sediments, diagenetic studies, the reconstruction of alteration processes and fluid flow, the detection of radiation damage or investigations of ultra-pure quartz and silica glass in technical applications. Ursachen, spektrale Charakteristika und praktische Anwendungen der Kathodolumineszenz (KL) von Quarz – eine Revision Untersuchungen von naturlichen und synthetischen Quarzproben mittels Kathodolumineszenz (KL) Mikroskopie und -spektroskopie, Elektron Paramagnetischer Resonanz (EPR) und Spurenelementanalysen zeigen verschiedene Lumineszenzfarben und Emissionsbanden, die unterschiedlichen intrinsischen und extrinsischen Defekten zugeordnet werden konnen. Die sichtbaren Lumineszenzfarben von Quarz werden durch unterschiedliche Intensitatsverhaltnisse der dominierenden Emissionsbanden zwischen 380 und 700 nm verursacht. Einige der KL Emissionen vom UV bis zum gelben Spektralbereich (175 nm, 290 nm, 340 nm, 420 nm, 450 nm, 580 nm) stehen im Zusammenhang mit intrinsischen Defekten. Die kurzlebigen Lumineszenzemissionen bei 380–390 nm sowie 500 nm werden mit kompensierten [AlO4/M+]-Zentren in Verbindung gebracht. Die KL-Emissionen im roten Spektralbereich bei 620 bis 650 nm haben ihre Ursache im “nonbridging oxygen hole centre” (NBOHC) mit verschiedenen Vorlauferzentren. Die unterschiedlichen KL-Farben und Emissionsspektren von Quarz konnen oft bestimmten genetischen Bildungsbedingungen zugeordnet werden und ermoglichen deshalb vielfaltige Anwendungen in den Geowissenschaften und in der Technik. Eine der gravierendsten Einsatzmoglichkeiten ist die Sichtbarmachung von Internstrukturen, Wachstumszonierungen und Defekten im Quarz, die mit anderen Analysenmethoden nicht oder nur schwer nachweisbar sind. Weitere wesentliche Untersuchungsschwerpunkte sind die Modalanalyse von Gesteinen, die Eduktanalyse klastischer Sedimente, Diageneseuntersuchungen, die Rekonstruktion von Alterationsprozessen und Fluidmigrationen, der Nachweis von Strahlungsschaden oder die Untersuchung von ultrareinem Quarz und Silikaglas fur technische Anwendungen.

Progress in application of cathodoluminescence (CL) in sedimentary petrology

Abstract: ¶Significant progress has been made in cathodoluminescence (CL) studies in the last three decades due to the application of enhanced methods such as high-resolution spectroscopy. The luminescence of all detrital and diagenetic minerals such as quartz, feldspar, phyllosilicates, carbonates, apatites, zircons etc. can now be quantitatively characterized by spectroscopy. For siliciclastic sediments, the potential for provenance studies has been explored because varying conditions at the time of formation (e.g. of quartz and zircons) might be encoded within the CL and therefore provide fingerprints for particular grain populations. Different cement generations allow a cement stratigraphy to be established and the deconvolution of the diagenetic history of carbonate and clastic sediments. CL investigations of carbonate, apatite and – with some limitations – siliceous biogenic skeletons provide evidence of growth zonation (ontogenetic cyclicities and changes in spatial distribution) and diagenesis (intra-skeleton cementation and recrystallization). However, further research using CL is required to fully understand detrital components, primary and secondary mineralization in sedimentary deposits and biogenic materials. We present here an, admittedly incomplete, overview of these developments.

The origin of photoluminescence from thin films of silicon-rich silica

Abstract: We have carried out a study of the photoluminescence properties of silicon‐rich silica. A series of films grown using plasma enhanced chemical vapor deposition over a range of growth conditions were annealed under argon at selected temperatures. Photoluminescence spectra were measured for each film at room temperature and for selected films at cryogenic temperatures. The photoluminescence spectra exhibit two bands. Fourier transform infrared and electron spin resonance spectroscopies were used to investigate bonding and defect states within the films. The data obtained strongly suggest the presence of two luminescence mechanisms which exhibit different dependencies on film growth conditions and postprocessing. We make assignments of the two mechanisms as (1) defect luminescence associated with oxygen vacancies and (2) radiative recombination of electron‐hole pairs confined within nanometer‐size silicon clusters (‘‘quantum confinement’’).