Scanning mid-IR-laser microscopy: an efficient tool for materials studies in silicon-based photonics and photovoltaics

A method of scanning mid-IR-laser microscopy has recently been proposed for the investigation of large-scale electrically and recombination-active defects in semiconductors and non-destructive inspection of semiconductor materials and structures in the industries of microelectronics and photovoltaics. The basis for this development was laid with a wide cycle of investigations on low-angle mid-IR-light scattering in semiconductors. The essence of the technical idea was to apply the dark-field method for spatial filtering of the scattered light in the scanning mid-IR-laser microscope together with the local photoexcitation of excess carriers within a small domain in a studied sample, thus forming an artificial source of scattering of the probe IR light for the recombination contrast imaging of defects. The current paper presents three contrasting examples of application of the above technique for defect visualization in silicon-based materials designed for photovoltaics and photonics which demonstrate that this technique might be an efficient tool for both defect investigation and industrial testing of semiconducting materials.Comment: DRIP-

Application of scanning mid-IR-laser microscopy for characterization of semiconductor materials for photovoltaics

The scanning mid-IR-laser microscopy was previously demonstrated as an effective tool for characterization of different semiconductor crystals. Now the technique has been successfully applied for the investigation of CZ SixGe1-x -- a promising material for photovoltaics - and multicrystalline silicon for solar cells. In addition, this technique was shown to be appropriate for imaging of polishing-induced defects as well as such huge defects as "pin holes". Besides, previously unexplained "anomalous" (cubic power) dependence of signal of the scanning mid-IR-laser microscope in the optical-beam-induced light scattering mode on the photoexcitation power obtained for mechanically polished samples has now been attributed to the excess carrier scattering on charged linear defects, likely dislocation lines. The conclusion is made in the article that the scanning mid-IR-laser microscopy may serve as very effective tool for defect investigations in materials for modern photovoltaics

Electromagnetically induced transparency on a single artificial atom

We present experimental observation of electromagnetically induced transparency (EIT) on a single macroscopic artificial “atom” (superconducting quantum system) coupled to open 1D space of a transmission line. Unlike in an optical media with many atoms, the single-atom EIT in 1D space is revealed in suppression of reflection of electromagnetic waves, rather than absorption. The observed almost 100% modulation of the reflection and transmission of propagating microwaves demonstrates full controllability of individual artificial atoms and a possibility to manipulate the atomic states. The system can be used as a switchable mirror of microwaves and opens a good perspective for its applications in photonic quantum information processing and other fields

Resonance fluorescence of a single artificial atom

An atom in open space can be detected by means of resonant absorption and reemission of electromagnetic waves, known as resonance fluorescence, which is a fundamental phenomenon of quantum optics. We report on the observation of scattering of propagating waves by a single artificial atom. The behavior of the artificial atom, a superconducting macroscopic two-level system, is in a quantitative agreement with the predictions of quantum optics for a pointlike scatterer interacting with the electromagnetic field in one-dimensional open space. The strong atom-field interaction as revealed in a high degree of extinction of propagating waves will allow applications of controllable artificial atoms in quantum optics and photonics

Unprecedented Coordination-Induced Bright Red Emission from Group 12 Metal-Bound Triarylazoimidazoles

Arylazoimidazoles are important dyes which were intensively studied in the past. In contrast, triarylazoimidazoles (derivatives which carry aryl substituents at the imidazole core) received almost no attention in the scientific literature. Here, we report a new family of simple and easily accessible triarylazoimidazole-group 12 metal complexes, which feature highly efficient photo-luminescence emission (Φ up to  0.44). Novel compounds exhibit bright red emission in solution, which could be excited with a visible light

Coherent flux tunneling through NbN nanowires

We demonstrate evidence of coherent magnetic flux tunneling through superconducting nanowires patterned in a thin highly disordered NbN film. The phenomenon is revealed as a superposition of flux states in a fully metallic superconducting loop with the nanowire acting as an effective tunnel barrier for the magnetic flux, and reproducibly observed in different wires. The flux superposition achieved in the fully metallic NbN rings proves the universality of the phenomenon previously reported for InO x . We perform microwave spectroscopy and study the tunneling amplitude as a function of the wire width, compare the experimental results with theories, and estimate the parameters for existing theoretical models.QN/Quantum NanoscienceApplied Science

Operating systems for in-board computer control system

Abstract: Paper presents structure and algorithms of operating system for in-board computer control system , that consists of PDP-11-like in-board computer with two-level main memory ,external bubble storage device and special local net connecting computer to input-output devices. Multitasking operating system inputs data asynchronously from local and remote sources , provides means for application tasks control and data exchanges , possess enough compatibility with operating system RT-11 to run application Fortran-programs . To facilitate in-board software development , special programming tools enable to emulate any subset of real operational environment of computer control system .Note: Research direction:Programming, parallel computing, multimedi