Perception of wellbeing programs held at the industrial enterprise by employees: preparatory stage of research

Актуальность данной темы исследования определяется потребностью промышленных предприятий в улучшениях своей деятельности за счет повышения благополучия сотрудников. Цель работы: выявить, какие программы предоставляет предприятие своим сотрудникам для повышения их благополучия, и проанализировать, какие программы востребованы на предприятии. Методы исследования: анализ, синтез, прогнозирование и моделирование. Результаты: проведенное исследование поможет выявить направления, в которых следует работать предприятию для повышения благополучия сотрудников. В работе будет рассмотрена деятельность АО "Сибирская Аграрная Группа".The relevance of the subject of the research is determined by requirement of industrial enterprises for improvements of the activities due to increase in wellbeing of employees. The main aim of the study is to identify the programs provided by the company to its employees to enhance their wellbeing, and to analyze which programs are in demand at the enterprise. Methods: analysis, synthesis, modeling and forecasting. Results. The study will help identify the directions for the company to follow for increasing wellbeing of the employees

Light-trapping structures for planar solar cells inspired by transformation optics

Optimal light absorption is decisive in obtaining high-efficiency solar cells. An established, if not to say the established, approach is to texture the interface of the light-absorbing layer with a suitable microstructure. However, structuring the light-absorbing layer is detrimental concerning its electrical properties due to an increased surface recombination rate (owing to enlarged surface area and surface defects) caused by the direct patterning process itself. This effect lowers the efficiency of the final solar cells. To circumvent this drawback, this work theoretically explores a transformation optics (TrO) inspired approach to map the nanopatterned texture onto a planar equivalent. This offers a pattern with the same optical functionality but with much improved electrical properties. Schwarz-Christoffel mappings are used for ensuring conformality of the maps. It leads to planar, inhomogeneous, dielectric-only materials for the light trapping structure to be placed on top of the planar light-absorbing layer. Such a design strategy paves a way towards a novel approach for implementing light-trapping structures into planar solar cells

Investigating the loess–palaeosol sequence of Bahlingen-Schönenberg (Kaiserstuhl), southwestern Germany, using a multi-methodological approach

Loess–palaeosol sequences (LPSs) are key archives for the reconstruction of Quaternary environmental conditions, but there is a lack of investigated records from the southern Upper Rhine Graben (southwestern Germany). To close this gap, a LPS at Bahlingen-Schönenberg was investigated at high resolution using a multi-method approach. Infrared stimulated luminescence screening reveals a major hiatus in the lower part of the LPS that according to luminescence dating is older than marine isotope stage (MIS) 4. The section above the hiatus formed by quasi-continuous loess sedimentation between ca. 34 and 27 ka, interrupted by phases of weak reductive pedogenesis. The fact that this pedogenesis is much weaker compared to corresponding horizons in the more northerly part of the Upper Rhine Graben could be due to regionally drier conditions caused by a different atmospheric circulation pattern at the time of deposition. Our results reinforce earlier notions that the major environmental shifts leading into the Last Glacial Maximum (LGM) of southern Central Europe significantly predate the transition of MIS 3 to 2 (ca. 29 ka). In particular, the last massive phase of loess accumulation started several thousand years prior to the arrival of glaciers in the foreland of the Alps, which raises questions regarding the source and transport paths of the dust. It is also noted that no loess dating to the LGM or the time thereafter was observed due to either a lack of deposition or later erosion.Löss-Paläoboden Sequenzen (LPS) sind Schlüsselarchive für die Rekonstruktion von quartären Umweltbedingungen, aber es mangelt an der Untersuchung solcher Abfolgen aus dem südlichen Oberrheingraben. Um diese Lücke zu schließen, wurde eine LPS bei Bahlingen-Schönenberg mit einem multimethodischen Ansatz hochauflösend untersucht. Die Untersuchung mit Infrarot Stimulierter Lumineszenz Screening zeigt einen Hiatus im unteren Teil der LPS, der laut Lumineszenzdatierungen älter ist als das Marine Isotopenstadium (MIS) 4. Der Abschnitt oberhalb des Hiatus bildete sich durch quasi-kontinuierliche Lössablagerung zwischen ca. 34 und 27 ka, unterbrochen von Phasen schwacher reduktiver Pedogenese. Da die Pedogenese im Vergleich zu entsprechenden Horizonten im nördlicheren Teil des Oberrheingrabens viel schwächer ausgeprägt ist, könnte dies auf regional trockenere Bedingungen zurückzuführen sein, verursacht durch ein anderes atmosphärisches Zirkulationsmuster zur Zeit der Ablagerung. Unsere Ergebnisse bestätigen frühere Annahmen, dass die großen Umweltveränderungen, die zum letzten glazialen Maximum (LGM) im südlichen Mitteleuropa führten, deutlich vor dem Übergang von MIS 3 zu 2 (ca. 29 ka) lagen. Insbesondere begann die letzte massive Phase der Lössakkumulation mehrere tausend Jahre vor der Ankunft der Gletscher im Alpenvorland, was Fragen zu den Quellen und Transportwegen des Staubs aufwirft. Es ist auch festzustellen, dass kein Löss aus dem LGM oder der Zeit danach gefunden wurde, entweder aufgrund fehlender Ablagerung oder späterer Erosion

Tailored Light Scattering through Hyperuniform Disorder in Self-Organized Arrays of High-Index Nanodisks

Arrays of nanoparticles exploited in light scattering applications commonly only feature either a periodic or a rather random arrangement of its constituents. For the periodic case, light scattering is mostly governed by the strong spatial correlations of the arrangement, expressed by the structure factor. For the random case, structural correlations cancel each other out and light scattering is mostly governed by the scattering properties of the individual scatterer, expressed by the form factor. In contrast to these extreme cases, it is shown here that hyperuniform disorder in self-organized large-area arrays of high refractive index nanodisks enables both structure and form factor to impact the resulting scattering pattern, offering novel means to tailor light scattering. The scattering response from the authors’ nearly hyperuniform interfaces can be exploited in a large variety of applications and constitutes a novel class of advanced optical materials

Correlated Disorder Substrate‐Integrated Nanodisk Scatterers for Light Extraction in Organic Light Emitting Diodes

A major loss mechanism in organic light emitting diodes (OLEDs) is the coupling of the emitter molecule light field to waveguide modes in the OLED thin film stack. In this work, a disordered 2D array of TiO$_{2}$ nanodisk scatterers is integrated into the OLED substrate to enable efficient light extraction from these waveguide modes. Fabrication of the nanodisks is based on a bottom-up, colloidal lithography technique and subsequent pattern transfer into high refractive index TiO$_{2}$ via reactive ion etching. The substrates are completed by spin-coating a polymer planarization layer before applying the OLED thin film stack. This ensures reproducible optoelectronic properties of the OLED through leaving the electrically active layers planar. Simultaneously, the nanodisks in close vicinity to the thin film stack ensure efficient out-of-plane scattering of waveguide modes. In a monochromatic OLED (center wavelength λ$_{0}$ = 520 nm), a 44.2%$_{rel}$ increase in external quantum efficiency is achieved in comparison to a device without scattering structure. An in-depth numerical analysis reveals that this significant enhancement is only partly due to the out-coupling of waveguide modes. Additional enhancement is suspected to result from out-coupling of substrate modes through scattering by the nanodisks. Further improvements to the scattering structure are numerically evaluated

Antireflective Huygens’ Metasurface with Correlated Disorder Made from High-Index Disks Implemented into Silicon Heterojunction Solar Cells

A large variety of different strategies has been proposed as alternatives to random textures to improve light coupling into solar cells. While the understanding of dedicated nanophotonic systems deepens continuously, only a few of the proposed designs are industrially accepted due to a lack of scalability. In this Article, a tailored disordered arrangement of high-index dielectric submicron-sized titanium dioxide (TiO$_{2}$) disks is experimentally exploited as an antireflective Huygens’ metasurface for standard heterojunction silicon solar cells. The disordered array is fabricated using a scalable bottom-up technique based on colloidal self-assembly that is applicable virtually irrespective of material or surface morphology of the device. We observe a broadband reduction of reflectance resulting in a relative improvement of a short-circuit current by 5.1% compared to a reference cell with an optimized flat antireflective indium tin oxide (ITO) layer. A theoretical model based on Born’s first approximation is proposed that links the current increase in the arrangement of disks expressed in terms of the structure factor S(q) of the disk array. Additionally, we discuss the optical performance of the metasurface within the framework of helicity preservation, which can be achieved at specific wavelengths for an isolated disk for illumination along the symmetry axis by tuning its dimensions. By comparison to a simulated periodic metasurface, we show that this framework is applicable in the case of the structure factor approaching zero and the disks’ arrangement becoming stealthy hyperuniform

Strategy for tailoring the size distribution of nanospheres to optimize rough backreflectors of solar cells

We study the light-trapping properties of surface textures generated by a bottom-up approach, which utilizes monolayers of densely deposited nanospheres as a template. We demonstrate that just allowing placement disorder in monolayers from identical nanospheres can already lead to a significant boost in light-trapping capabilities. Further absorption enhancement can be obtained by involving an additional nanosphere size species. We show that the Power Spectral Density provides limited correspondence to the diffraction pattern and in turn to the short-circuit current density enhancement for large texture modulations. However, in predicting the optimal nanosphere size distribution, we demonstrate that full-wave simulations of just a c-Si semi-infinite halfspace at a single wavelength in the range where light trapping is of main importance is sufficient to provide an excellent estimate. The envisioned bottom-up approach can thus reliably provide good light-trapping surface textures even with simple nanosphere monolayer templates defined by a limited number of control parameters: two nanosphere radii and their occurrence probability

Roadmap on photonic metasurfaces

Funding: C.R. and U.L. acknowledge support through the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy via the Excellence Cluster 3D Matter Made to Order (EXC-2082/1, Grant No. 390761711). A.B.E. acknowledges support through the Cluster of Excellence PhoenixD (EXC 2122, Project ID No. 390833453). I.F.-C. and C.R. acknowledge support through the CRC Waves: Analysis and Numerics (SFB 1173, Grant No. 258734477. K.A. acknowledges funding from the Swiss National Science Foundation (Project No. PZ00P2_193221).Here we present a roadmap on Photonic metasurfaces. This document consists of a number of perspective articles on different applications, challenge areas or technologies underlying photonic metasurfaces. Each perspective will introduce the topic, present a state of the art as well as give an insight into the future direction of the subfield.Peer reviewe

Optische Nahfeld-Wechselwirkungen von Plasmonen mit ihrer Umgebung

Metallic nanostructures exhibit unique optical properties. These are caused by plasmon excitations, which constitute resonant and collective oscillations of the conduction electrons of the metal. Plasmons feature resonantly enhanced light scattering and absorption, strong enhancements of the optical near field in comparison with the irradiated or emitted light, and strong localization of light energy into subwavelength volumes. Resonance frequency and width of the plasmon are not only dependent on the metallic nanostructure itself but in particular on the surroundings of the structure. These properties of metallic nanostructures may be interesting for a multitude of applications, e.g. novel sensors, miniaturized optical elements, and light management in LEDs or solar cells. In the work presented in this thesis, the optical nearfield interactions of plasmons with their environment are investigated. Here, surface plasmons, which are electron density oscillations propagating along a metal surface, as well as particle plasmons, which are electron density oscillations bound to a metallic nanoparticle, are covered. The first part of this thesis is dedicated to surface plasmons in periodically modulated surroundings. The periodic modulation is introduced by a high-refractive index dielectric grating covering a smooth metal film. The grating enables the excitation of surface plasmons by light irradiation and at the same time strongly influences the dispersion relation of the surface plasmon. In particular, band gaps emerge which together with the band edge modes, i.e. the surface plasmon modes at the upper and lower edges of the band gap, are the focal point of this work. The dependence of the near and far field properties of the plasmon-polaritonic dispersion relation on the grating parameters are investigated experimentally, theoretically and by rigorous electrodynamical calculations. Strong dependencies are found. The band gap width responds extremely sensitively on the exact grating parameters. As will be shown here, this also applies to the radiation damping of the band edge modes, which may vary over a broad range and constitutes an important quantity with regard to potential applications. In this work, the physical causes of these effects, e.g. coupling with further resonances of the grating, are discussed. The results constitute an important contribution to the understanding of surface plasmon in periodic structures. The interactions between metallic nanoparticles and dipole emitters, i.e. oscillating point dipols, are investigated in the second part of this thesis. The excitation rate, which describes the gain of energy of an emitter from incoming light, as well as the radiative quantum efficiency of a lossy emitter, which describes the emission capability of an emitter, can be enhanced by the coupling between the particle plasmon of a nanoparticle and the dipole emitter. In this case, the particle acts as an optical nanoantenna. This phenomenon may be exploited, e.g., to increase the conversion efficiency of LEDs or solar cells. In this work, the influence of an aluminum nanodisk on the aforementioned quantities is investiged in detail for the first time. Disk shaped particles can be prepared in well-defined spatial arrangements, in a large number, and on large areas onto a substrate with less experimental effort than spherical particles, which is advantageous in terms of possible applications. Silver nanospheres have already been subject of much previous research in the literature and serve here as a reference. The investigations reveal that regarding excitation and emission enhancement of a dipole emitter an aluminum nanodisk outperforms a silver nanosphere in most circumstances. Within the discussion section, a model is introduced which is able to describe the physical mechanisms of the discovered dependencies qualitatively. The results are explained on the basis of this model and supporting rigorous numerical calculations

Optische Nahfeld-Wechselwirkungen von Plasmonen mit ihrer Umgebung

Metallic nanostructures exhibit unique optical properties. These are caused by plasmon excitations, which constitute resonant and collective oscillations of the conduction electrons of the metal. Plasmons feature resonantly enhanced light scattering and absorption, strong enhancements of the optical near field in comparison with the irradiated or emitted light, and strong localization of light energy into subwavelength volumes. Resonance frequency and width of the plasmon are not only dependent on the metallic nanostructure itself but in particular on the surroundings of the structure. These properties of metallic nanostructures may be interesting for a multitude of applications, e.g. novel sensors, miniaturized optical elements, and light management in LEDs or solar cells. In the work presented in this thesis, the optical nearfield interactions of plasmons with their environment are investigated. Here, surface plasmons, which are electron density oscillations propagating along a metal surface, as well as particle plasmons, which are electron density oscillations bound to a metallic nanoparticle, are covered. The first part of this thesis is dedicated to surface plasmons in periodically modulated surroundings. The periodic modulation is introduced by a high-refractive index dielectric grating covering a smooth metal film. The grating enables the excitation of surface plasmons by light irradiation and at the same time strongly influences the dispersion relation of the surface plasmon. In particular, band gaps emerge which together with the band edge modes, i.e. the surface plasmon modes at the upper and lower edges of the band gap, are the focal point of this work. The dependence of the near and far field properties of the plasmon-polaritonic dispersion relation on the grating parameters are investigated experimentally, theoretically and by rigorous electrodynamical calculations. Strong dependencies are found. The band gap width responds extremely sensitively on the exact grating parameters. As will be shown here, this also applies to the radiation damping of the band edge modes, which may vary over a broad range and constitutes an important quantity with regard to potential applications. In this work, the physical causes of these effects, e.g. coupling with further resonances of the grating, are discussed. The results constitute an important contribution to the understanding of surface plasmon in periodic structures. The interactions between metallic nanoparticles and dipole emitters, i.e. oscillating point dipols, are investigated in the second part of this thesis. The excitation rate, which describes the gain of energy of an emitter from incoming light, as well as the radiative quantum efficiency of a lossy emitter, which describes the emission capability of an emitter, can be enhanced by the coupling between the particle plasmon of a nanoparticle and the dipole emitter. In this case, the particle acts as an optical nanoantenna. This phenomenon may be exploited, e.g., to increase the conversion efficiency of LEDs or solar cells. In this work, the influence of an aluminum nanodisk on the aforementioned quantities is investiged in detail for the first time. Disk shaped particles can be prepared in well-defined spatial arrangements, in a large number, and on large areas onto a substrate with less experimental effort than spherical particles, which is advantageous in terms of possible applications. Silver nanospheres have already been subject of much previous research in the literature and serve here as a reference. The investigations reveal that regarding excitation and emission enhancement of a dipole emitter an aluminum nanodisk outperforms a silver nanosphere in most circumstances. Within the discussion section, a model is introduced which is able to describe the physical mechanisms of the discovered dependencies qualitatively. The results are explained on the basis of this model and supporting rigorous numerical calculations