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The continuous development of innovative optical materials with lanthanoid ions as activators has emerged as a modern sector of materials chemistry. The experience with the fabrication of single crystals with the optical float zone has motivated one to investigate the luminescence of Nd3+ and Ho3+ ions in the garnets (Gd3−xREx)In2Ga3O12 (RE = Nd and Ho, x = 0; 0.15–0.30). Upon usage of an Ar/O2 (80:20 ratio) atmosphere and application of an auxiliary pressure (6 bar) to suppress In2O3 evaporation, single‐crystalline domain sizes in the order of ≈6 × 6 × 1 mm3 are obtained. Structural analysis confirms the formation of a cubic garnet phase with space group Ia3¯d $I a \\bar{3} d$ , with the substituents incorporated in accordance with Vegard's law. Backscattered electron imaging and energy‐dispersive X‐ray spectroscopy are conducted, demonstrating a homogeneous elemental distribution within the crystals. Photoluminescence studies are carried out, revealing the characteristic narrow‐line 4f n → 4f n transitions of Nd3+ and Ho3+, with decay times in the submillisecond range, suggesting non‐negligible cross‐relaxation effects are present. Despite this, the large nearest‐neighbor Gd–Gd distance (3.88 Å) in Gd3In2Ga3O12 and the low phonon cutoff energy (≈700 cm−1) are found to limit cross‐relaxation pathways, preserving significant photoluminescence brightness. These results highlight the potential of Gd3In2Ga3O12:RE3+ single crystals as promising candidates for advanced optical applications. Nd3+‐ and Ho3+‐doped Gd3In2Ga3O12 single crystals have been successfully synthesized via the optical float zone method. Their structure and optical characterization demonstrate efficient narrow‐line 4f–4f emission, low cross‐relaxation, and bright photoluminescence, indicating their potential as advanced optical materials for photonic applications.

Using the penetration and transientness of Terahertz pulses and the photoconductive delayed detection method, the tomographic imaging of the interior of the object based on the time of flight can be realized. By comparing the transmittance of several crystals and polymers in the Terahertz band, Polymethylpentene (TPX) was selected as the material of Terahertz lens, and High Resistivity Float Zone Silicon (HRFZ-Si) as the material of beam splitter; By comparing the focal depth of normal incidence and oblique incidence optics system, the normal incidence optical system was used to realize time-of-flight imaging; Using the idea of optical-mechanical integration, the corresponding optical camera is designed according to the normal incidence optical system, and the peak-to-valley map and thickness map of the Lithium cobaltate coating of aluminum foil were obtained by time-of-flight imaging, and the defects such as complete shedding of the coating and uneven thickness were observed. The results show that the normal incidence optical system can realize Terahertz time-of-flight imaging and is applicable in the industrial nondestructive testing field.

The Green Edge project was designed to investigate the onset, life, and fate of a phytoplankton spring bloom (PSB) in the Arctic Ocean. The lengthening of the ice-free period and the warming of seawater, amongst other factors, have induced major changes in Arctic Ocean biology over the last decades. Because the PSB is at the base of the Arctic Ocean food chain, it is crucial to understand how changes in the Arctic environment will affect it. Green Edge was a large multidisciplinary, collaborative project bringing researchers and technicians from 28 different institutions in seven countries together, aiming at understanding these changes and their impacts on the future. The fieldwork for the Green Edge project took place over two years (2015 and 2016) and was carried out from both an ice camp and a research vessel in Baffin Bay, in the Canadian Arctic. This paper describes the sampling strategy and the dataset obtained from the research cruise, which took place aboard the Canadian Coast Guard ship (CCGS) Amundsen in late spring and early summer 2016. The sampling strategy was designed around the repetitive, perpendicular crossing of the marginal ice zone (MIZ), using not only ship-based station discrete sampling but also high-resolution measurements from autonomous platforms (Gliders, BGC-Argo floats …) and under-way monitoring systems. The dataset is available at https://doi.org/10.17882/86417 (Bruyant et al., 2022).

This experiment deals with the influence of co-doping with oxygen and hydrogen and also annealing parameters, temperature and excitation power on the Er related photoluminescence (PL) of silicon. The ultimate goal is to optimise the PL intensity of the Er 3+ internal transition to make at room-temperature luminescence possible. Silicon is a very inefficient light emitter, because of the low radiative recombination rate due to the indirect band gap. However, by adding optically active impurities such as erbium, Si can be made luminescent. Silicon is an ideal material for the fabrication of optical waveguides that are compatible with optical telecommunication technology at 1.54µm, because of its high transparency and high refractive index at this wavelength. Co-doping with oxygen and hydrogen can enhance the initial Er luminescence. To investigate the influence of oxygen and hydrogen on the diffusion process and the luminescence intensity, samples were doped with erbium, oxygen and hydrogen at different concentrations that were implanted both on Float Zone (FZ) and Czochralski (CZ) silicon wafers. In FZ silicon, the samples implanted with both oxygen and hydrogen showed the highest luminescence yield with a six times higher peak intensity as compared to samples implanted with only erbium and a two times higher peak intensity as compared to samples with erbium and oxygen, in accordance with previous results. However, identified by the line position and contrary to previous results on CZ-Si, the luminescence stems from an erbium-oxygen impurity complex and not from the so-called cubic centre. In CZ samples doped with erbium, oxygen and hydrogen show a 3 times higher intensity as compared to samples doped only with erbium and oxygen. Although the PL lines of the cubic centre are visible, they do not exhibit the strongest luminescence. In samples doped only with erbium and hydrogen and annealed at 900°C, we observe luminescence from only the cubic centre. Although the appearance of the cubic centre in these samples is most likely due to out-diffusion of erbium in the absence of oxygen, hydrogen again enhances the luminescence intensity by a factor 2.

The optical properties of float-zone (FZ) silicon irradiated with swift heavy ions (SHI) are studied. In the low-temperature photoluminescence spectra, a broad peak in the range 1.3–1.5 μm is evident along with the well-known X, W, W', R, and C lines. In this case, it is found that, as the irradiation dose is increased in the range 3 × 10 11 –10 13 cm –2 , the photoluminescence peak falls and narrows and, at the same time, its maximum shifts to longer wavelengths.

For high-efficiency silicon wafer solar cells, Auger recombination is becoming one of the most important efficiency limiting factors. For this purpose it is desirable to be able to use different Auger recombination parameterisations in advanced computer simulations. In this paper we present a method to implement arbitrary Auger parameterisations in the software package Sentaurus TCAD, enabling two- and three-dimensional simulation of solar cells using different Auger parameterisations. As examples, we implemented and investigated three different Auger parameterisations (proposed by Altermatt et al., by Kerr and Cuevas, and by Richter et al.) from the literature. For verification, we simulate Auger lifetimes for different doping densities and injection levels in crystalline silicon. The simulated Auger lifetimes are found to agree well with analytical solutions (differences less than 0.001 %). We then employ the three different Auger parameterisations for fitting measured effective lifetime curves of both n -type and p -type float-zone silicon lifetime samples and show which models are applicable under which conditions. We further compare the difference between the three Auger parameterisations by simulating characteristics of a screen-printed aluminium local back surface field silicon wafer solar cell. The simulation results agree well with the characterisation results. We find that the choice of Auger parameterisation can lead to significant differences in the predicted solar cell behaviour under one-Sun illumination. We demonstrate that different Auger parameterisations may result in significant differences in the blue response, by simulating a heavily doped emitter of an aluminium local back surface field silicon wafer solar cell.

Topochemical fluorination offers a low--temperature route for modifying the anion chemistry and electronic ground states of layered transition-metal oxides, providing access to metastable phases and functionalities that are not able to be achieved through conventional solid--state synthesis. Despite extensive work on polycrystalline samples and thin films, topochemical fluorination of bulk single crystals has not been studied, limiting insights into intrinsic structure property relationships. Here, we investigate the topochemical fluorination of optical float zone grown (OFZ) La\\(_2\\)NiO\\(_4+\\) single crystals using polymer-based PTFE, PVDF and inorganic CuF\\(_2\\) fluorination agents and compare it to our topochemical pathways of reduction of LaNiO\\(_3-x\\). By systematically investigating direct and indirect contact reaction pathways, we can understand fluorination mechanisms, quantify the degree of fluorine incorporation, and evaluate the resulting structural and magnetic modifications in a detail that was not possible in powder and thin films. Powder and single--crystal X-ray diffraction reveal that fluorination proceeds without destroying the Ruddlesden--Popper framework, while inducing lattice parameter changes consistent with anion intercalation in the bulk and ion exchange on the surface. This even induces a clear superstructure, which was not reported before and extends the understanding of anion insertion reactions beyond what is known on stage ordering in nickelates. Energy-dispersive X--ray spectroscopy confirms strong fluorine incorporation on the surface and reduced homogeneity in the bulk. Magnetic susceptibility measurements demonstrate a change in antiferromagnetic ordering upon fluorination.

We have grown single crystals of Gd0.5Sr0.5MnO3 (GSMO50) using optical float zone method. We report AC susceptibility measurements carried out on these single crystals at various frequencies in the range 42 to 10,000 Hz under the application of small AC magnetic field (∼170 mOe). The frequency dependence of the peak temperature follows a critical slowing down with exponent zν=1.13(4) as seen in the dynamical scaling analysis reported in the present paper. We observe that the glass-like phase in GSMO50 (∼ below 32 K) is very sluggish (spin flipping time τ0=4×10−6 sec).

The magnetic behavior of La0.85Sr0.15CoO3 single crystals and polycrystals has been subjected to a controversial debate for the last several years; while some groups show evidence for phase separation, others show spin-glass (SG) behavior. Here, we present a comprehensive investigation of the structural, ac susceptibility, and dc magnetization properties of La0.85Sr0.15CoO3 single crystals grown by float zone method. The structural analysis of XRD data by Rietveld refinement reveals the single crystallographic phase. The ac susceptibility results exhibit a frequency dependent peak shift (∼2 K) and time-dependent memory effect below the freezing temperature. The characteristic time scale τo calculated from this peak shift is found to be of ∼10−13 s which matches very well with typical values observed for a SG system. Further, the peak shift of the zero-field-cooling curves to lower temperature at higher dc fields is well described by the well-known de Almeida Thouless line, a characteristic of SG behavior. Thus, all our experimental findings confirm the existence of SG behavior in La0.85Sr0.15CoO3 single crystals.

The purpose of this work was to investigate the surface passivation of n-type float zone silicon substrates using a double layer composed of hydrogenated amorphous silicon (a-Si:H) and hydrogenated amorphous silicon nitride (SiN:H). The layers were deposited by using an Electron Cyclotron Resonance Plasma Enhanced Chemical Vapour Deposition (ECR-PECVD) reactor. In this study, we report on the effect of deposition temperature and thickness of the a-Si:H layer on the surface passivation quality of silicon. The effect of SiN:H layer for coating the a-Si:H is reported as well. We recorded effective minority carrier lifetime values close to 1 ms for the best combination of temperature deposition and layer thickness for the a-Si:H film stacked with a SiN:H coating layer. FTIR measurements were systematically carried out for the different layers deposited in order to quantify the hydrogen content and tentatively link these measurements with the passivation level obtained. This work also shows that an improvement of the surface passivation quality occurs when a capping SiN:H layer is deposited on top of the a-Si:H layer that can be partly attributed to the annealing step occurring during the SiN:H layer deposition at 400 °C.