Zinc manganese selenide, a type II-VI semiconductor with a tunable bandgap, is attracting considerable interest due to its diverse applications, including light-emitting diodes and spintronics. In this work, the growth of Zn 1x Mn x Se semiconductor materials was achieved using the vertical Bridgman method at high temperatures and pressures with varying Mn concentrations in the range of x = 0-0.42. The real chemical composition was measured using EDS spectroscopy. X-ray diffraction was used to determine the crystallographic parameters and the structure of the grown crystals. We report the temperature-dependent photoluminescence studies of Mn 2+ in ZnSe crystals over a 10-300K temperature range using a Helium cryostat. The band gap energy of the samples is blue-shifted with increasing Mn content. The exciton energy was followed by the temperature, and a Varshni fitting was determined. Decay time-resolved dependence on the composition and the temperature was examined and discussed. Non-radiative recombination is more prevalent in Mn 2+ -rich crystals.

This study examines the optical and thermal properties of CdSxTe1-x mixed crystals grown using the Vertical Bridgman technique, with sulfur compositions ranging from x = 0 to x = 0.23. The elemental composition of sulfur was verified using SEM/EDS analysis. Photopyroelectric (PPE) calorimetry was utilized to measure thermal diffusivity and effusivity, enabling the calculation of thermal conductivity. Transmittance spectroscopy and Piezoelectric Photothermal Spectroscopy (PPS) were employed to determine the optical band gap for all samples. PPS was also used to estimate the thickness of the surface-damaged layer. Thermal conductivity decreased from 5.45 W center dot m-1 center dot K-1 (x = 0) to 1.71 W center dot m-1 center dot K-1 (x = 0.23), while bandgap energy varied from 1.5 eV to 1.43 eV. The influence of the incorporation of sulfur on the optical and thermal properties of CdSxTe1-x crystals was discussed.

Zinc manganese selenide (ZnMnSe), a II–VI semiconductor with an adjustable bandgap, has attracted significant interest due to its potential applications in radiation detection and optoelectronics. In this work, Zn1-xMnxSe crystals with manganese contents ranging from 0 to 0.15 were grown using a high-pressure Bridgman–Stockbarger technique. The chemical composition and the stoichiometry were verified through energy-dispersive X-ray spectroscopy (EDS). The thermal characteristics of the crystals were then explored using photopyroelectric (PPE) calorimetry, employing both back- and front-detection configurations. This approach allowed the determination of thermal diffusivity and effusivity, which were subsequently combined to calculate the thermal conductivity of each sample. The results for ZnSe were consistent with the literature value, confirming the reliability of the measurements. A systematic decrease in thermal conductivity was observed with increasing Mn concentration, attributed to enhanced phonon scattering due to lattice disorder. These findings offer valuable insights into the influence of Mn incorporation on the thermal transport behavior of Zn1-xMnxSe semiconductors.

Mixed Zn1-xMnxSe crystals, belonging to the family of diluted magnetic semiconductors, are of particular interest for optoelectronic and spintronic applications due to their tunable electronic and thermal properties. In this work, Zn1-xMnxSe single crystals with Mn concentrations between x = 0 and 0.42 were grown using the Bridgman-Stockbarger vertical method. The chemical composition of the samples was determined by EDS spectroscopy coupled with scanning electron microscopy (SEM), confirming the atomic proportions of Zn, Mn, and Se in each crystal. The optical properties, in particular the band gap energy and refractive index, were studied as a function of Mn incorporation using Ellipsometry. The thermal properties, such as diffusivity, effusivity, and conductivity, were characterized by photopyroelectric calorimetry. The experimental results, interpreted using Adachi's theoretical model, highlight a clear correlation between composition, optical behavior, and thermal response. This study contributes to a better understanding of the fundamental properties of Zn1xMnxSe and highlights its potential for the development of advanced devices in optoelectronics and spintronics.

Zinc manganese selenide, a type II-VI semiconductor with a tunable bandgap, is attracting considerable interest due to its diverse applications, including light-emitting diodes and spintronics. In this work, the growth of Zn1-xMnxSe semiconductor materials was achieved using the vertical Bridgman method at high temperatures and pressures with varying Mn concentrations in the range of x = 0–0.42. The real chemical composition was measured using EDS spectroscopy. X-ray diffraction was used to determine the crystallographic parameters and the structure of the grown crystals. We report the temperature-dependent photoluminescence studies of Mn2+ in ZnSe crystals over a 10–300K temperature range using a Helium cryostat. The band gap energy of the samples is blue-shifted with increasing Mn content. The exciton energy was followed by the temperature, and a Varshni fitting was determined. Decay time-resolved dependence on the composition and the temperature was examined and discussed. Non-radiative recombination is more prevalent in Mn2+-rich crystals.

The present study investigates the evolution of optical and thermophysical properties in beryllium-alloyed ZnSe single crystals (Zn1-xBexSe) synthesized with Be concentrations in the range 0 <= x <= 0.27. Crystal growth was carried out via a high-pressure, high-temperature variant of the Bridgman technique. Powder X-ray diffraction analysis verified that all compositions crystallize in a single-phase zinc-blende structure, exhibiting a systematic lattice contraction with increasing Be incorporation. Refined lattice parameters obtained through Rietveld analysis were further used to quantify Be substitution according to Vegard's law. Elemental homogeneity and stoichiometry were assessed using energy-dispersive X-ray spectroscopy. Optical band gaps were determined from the Tauc plot method applied to optical transmittance data, demonstrating that Be alloying enables bandgap adjustment across approximately 2.59-3.06 eV. Thermophysical properties were investigated through photopyroelectric calorimetry using both front and rear detection configurations. This approach enabled the determination of thermal diffusivity and thermal effusivity, from which the thermal conductivity was calculated. The influence of beryllium content on optical behavior and thermal transport is systematically analyzed, showing that Be-induced lattice disorder enhances phonon scattering, resulting in a reduction of thermal conductivity.

The increasing demand for high-performance energy storage devices has stimulated interest in advanced electrolyte materials. Among them, ionic liquids (ILs) stand out for their thermal stability, wide electrochemical windows, and good ionic conductivity. When doped into polymeric matrices, these ionic liquids form hybrid polymeric electrolytes that synergize the benefits of both liquid and solid electrolytes. This study explores a polymeric electrolyte based on polyethylene oxide (PEO) doped with tributylmethylphosphonium iodide (TMPI) and ammonium iodide (NH4I), focusing on its synthesis, structural and electrical properties, and performance in energy storage devices such as dye-sensitized solar cells and supercapacitors. Strategies to improve its ionic conductivity, mechanical and chemical stability, and electrode compatibility are also discussed, along with future directions in this field.

Perovskite solar cells (PSCs) are a category of third-generation solar cells technology, which gained significant attention due to their cost-effectiveness and electricity generation capabilities. However, there are concerns regarding the use of lead (Pb) in traditional PSCs, particularly its potential impact on the environment and human health. Consequently, the advancement of lead-free perovskite solar cells is of utmost importance to safeguard both the environment and human well-being. Tin-based perovskites present a promising alternative to lead-based PSCs. Tin (Sn) has shown promising optoelectronic properties and can be used as a substitute for lead. However, there are obstacles associated with the weak stability of Sn2+ ions that must be overcome in order to develop tin-based PSCs that are both extremely stable and efficient. This review specifically examines the progress made within the field of lead free tin-based perovskite solar cells, with a particular focus on stability and efficiency. The discussion delves into the effect of various cations and their compositions on the devices' stability. It is important to mention that devices based on tin halide perovskites have achieved an unexpectedly high level of efficiency in a short amount of time. Moreover, this review provides a summary of the strategies that have been employed to enhance, and improve the stability and the overall efficiency of tin-based PSCs.

Due to their simple structure (two bond species randomly arranged on a cubic lattice), the zincblende A1−xBxC semiconductor alloys (zb-SCA) set a benchmark to explore how physical properties are impacted by disorder. A longstanding controversy was whether the lattice dynamics (phonons), governed by the bond force constant, i.e., a local physical property, is blind to the alloy disorder or actually sees it. Over the past two decades, we introduced the percolation model (PM) that distinguishes between like bonds depending on whether they vibrate in same (homo) or alien (hetero) environments (1-bond → 2-mode scheme). The PM seems to apply universally among zb-SCA, and hence would solve the controversy in favor of the second scenario. Here our aim is to take one step forward and complete in the main lines a PM-based taxonomy of high-pressure vibration spectra of zb-SCA. This might clarify how a disordered atomic alloy, seen by each bond species in terms of a homo/hetero composite (i.e., at the unusual mesoscopic scale) from the angle of the PM, behaves when the lattice shrinks under hydrostatic pressure. We focus on Cd1−xZnxTe as the last sensitive pending case. This tidying-up exercise is attractive at the fundamental level and useful for projecting phonon-based devices involving zb-SCA.

Taking into account energy demand a new highly conducting ionic liquid (IL) c (EmImTCM) mixed corn starch (CS) biopolymer electrolyte is synthesized for dual electrochemical application electric double layer capacitor (EDLC) and the dye-sensitized solar cell (DSSC) application. Electrical, structural, thermal, and optical studies are carried out in detail and presented in this communication. Maximum conducting IL-incorporated biopolymer electrolyte film has been sandwiched between electrodes to develop EDLC and DSSC. The sandwich-structured EDLC delivers a high specific capacitance of 250 F/gram while DSSC shows 1.44% efficiency at one sun condition.

This work investigates the optical and thermal properties of zinc sulfide ZnS single crystal mixed with magnesium (Zn1_xMgxS). The starting material's Mg mass ratio (x) varied from x = 0 to x = 0.34. The investigated alloys were grown using the vertical modified Bridgman method. The SEM/EDS method was used to check the accurate composition of the crystals. X-ray diffraction analysis was applied to check the phase and crystallinity of the grown alloys. The band gap energy was measured for each sample by transmission spectroscopy. The dynamical thermal properties were measured using photopyroelectric calorimetry (PPE). The thermal diffusivity and effusivity values were extracted from the experiment, allowing the calculation of the specimens' thermal conductivity. The optical and thermal properties of grown Zn1_xMgxS crystals versus composition were discussed.

The paper presents the new results of photothermal studies on recombination parameters of a series of Cd(1-x)Zn (x)Te mixed crystals as a function of their composition parameter x in the range from x = 0 (CdTe) to x = 1 (ZnTe). The nondestructive photothermal radiometry (PTR) method has been used for the effective determination of the effective carrier lifetimes across various concentrations of Zn in a series of Cd(1-x)Zn(x)Te crystals. They changed from 0.1 mu s for CdTe crystal to 2 mu s for ZnTe crystal. The theoretical model which includes infrared optical absorption coefficient has been taken for interpretation of experimental characteristics of the PTR signal. The behavior of the average lifetime of carriers as a function of a composition of crystals was investigated. It is of a great importance for the further application development based on the Cd(1-x)Zn(x)Te crystals.

Inelastic neutron scattering measurements on the hexagonal Zn67Mg33S semiconductor alloy reveal a bimodal pattern of the optical modes across the Brillouin zone, confirmed by first-principles simulations. Such modes are sensitive to the local fluctuations in the composition inherent to random Zn/Mg alloying, distinguishing homo from hetero environments of a given bond (1-bond/2-mode), as is formalized for cubic alloys by the percolation model. The latter model thus emerges as a generic framework for systematizing the optical modes of semiconductor alloys in various crystal structures.

Cubic pseudo-unary A1-xBx high-entropy metallic alloys and pseudo-binary A1-xBxC disordered semiconductor alloys set a benchmark to explore how physical properties are impacted by disorder. Through its diversity, the lattice dynamics offers a unique playground to assign the relevant length scales at which operate various kinds of disorders induced by alloying. (i) In high-entropy metallic alloys, the overdamping of the bond-collective (multi-bond→1-mode) acoustic modes at short wavelength originates from force-constant fluctuations. (ii) In semiconductor alloys, the lattice mismatch splits, at any wavelength, the bond-specific (1-bond→1-mode) optical modes in duos distinguishing "same" from "alien" environments, as explained by the percolation model. Zn1-xMgxS is ideal to test both univocal assignments. Its force-constant disorder is small, reducing the cause for overdamping of the acoustic modes. Its local strain is inverted, the lighter substituent being the larger one and forming the longer bond. This forecasts a dramatic inversion of the mode-duos. Further, its wurtzite structure enables (iii) to test whether/how the percolation model for the mode-duos transfers under lowering the crystal symmetry from cubic to hexagonal. The triple acoustic-(i)/optical-(ii-iii) test on Zn1-xMgxS, combining inelastic neutron scattering with first-principles simulations, is positive. This highlights a few key points behind the lattice dynamics of atomic alloys.

Cadmium zinc telluride (CdxZn1-xTe) is frequently used material for the production of nuclear radiation detectors and solar cells. Therefore, the characterization of its quality by different methods is very important. This work is devoted to the development of a technique for mapping the poly-crystalline structure of CdxZn1-xTe, alternative to the X-ray technique usually used for this goal. In comparison with X-ray, the non-destructive and contactless picosecond laser ultrasonic technique provides numerous advantages, including simplicity of the analysis of the results and possibility to work with very compact laser spots (about 1 µm) probing the sample. As a step to achieve this goal, picosecond laser ultrasonics is applied in this work to study the samples in the form of 8 mm-diameter discs of 1 mm thickness including several connected disoriented crystals of CdxZn1-xTe. The experimental study is performed using classical pump-probe experimental set-up based on Tsunami femtosecond laser and delay line with moving retro-reflector. The sound velocities of the samples have been evaluated from frequency spectra of obtained signals, using the literature data on the index of refraction. Then, the value of the longitudinal sound velocity in the direction perpendicular to the sample surface is traced as a function of Zn concentration. Finally, measured sound velocities are compared with their available theoretical evaluation, using statistical analysis.

The inclusion of lead in the Champion perovskite material MAPbI3 is a detrimental factor in the commercialization of lead based perovskite solar cells. This is mainly due to the toxicity of lead and also due to degradation of MAPbI3 in ambient condition into hazardous chemicals which are toxic to the environment [1]. Due to these factors, though the Hybrid Organic Inorganic Lead based PSCs exhibit excellent photovoltaic effect and photo conversion efficiency (PCE), yet numerous theoretical and experimental studies have been done to replace lead with suitable elements such as Sn, Ge, Bi etc. This research work focusses on replacing Pb from MAPbI3, with different wt% of Bi such as 1%, 2%, 4% and 8% and analyzing its effect on the stability and efficiency of the PSC. These solutions of Bi doped perovskite are coated on the FTOs and are fabricated under room ambient condition in the sandwich structure. The results exhibit lower efficiency of Bismuth doped PSCs but it shows remarkable stability comparable to that of MAPbI3.

This paper deals with the synthesis and properties of new ternary mixed Cd1-xBexTe (cadmium beryllium telluride) crystal-based electrodes for photovoltaic cells which is a modified version of dye- sensitized solar cells. We determined the thermal stability and photovoltaic performance of the obtained devices. Cd1-xBexTe crystals are grown using the Bridgman technique at high temperatures and pressure for different compositions. Using the modified doctor blade method, we fabricated dye-sensitized solar cells (DSSC) using Cd1-xBexTe-based film as working electrodes. The mixed crystals with the highest beryllium content (10 %) and the lowest (1 %) are used. At the same time, the counter electrode and polymer electrolytes are common. Comparative studies with standard DSSC are also undertaken to compare the stability and charge mechanism. As prepared, DSSC using ternary Cd1-xBexTe showed efficiency as high as 3.11 % at 1 sun condition. The life span measurement indicated promising results, and DSSC is stable up to 720 h with a reasonable decrease in fill factor from 84 to 55.

This article presents new research on the surface condition of bulk crystal samples after the following stages of surface treatment: grinding, polishing, and etching. Furthermore, it shows how the surface condition affects the photothermal signal’s spectral amplitude and phase characteristics (PZE). A new theoretical interpretation of the photothermal spectra of CdTe samples after different surface treatments is proposed. We demonstrate that the piezoelectric method is susceptible to the surface condition, and it allows for the estimation of the thickness of surface-damaged layers of samples, and for the analysis of their thermal parameters. The roughness of surfaces obtained from the AFM pictures is estimated and compared to the photothermal results.