[This retracts the article DOI: 10.1016/j.heliyon.2023.e22533.].

The advancement in the development of high-efficiency cyan-green emitting phosphors is pivotal for achieving high-color-quality full-visible-spectrum white light-emitting diodes (WLEDs). In this study, a series of novel cyangreen emitting BaLu2Al3ScGe1-ySiyO12: xCe3+ (BLASGe1-ySiyO: xCe3+) phosphors were successfully synthesized. X-ray diffraction analysis confirmed that all samples possess a typical garnet crystal structure, belonging to the Ia3d space group. The emission spectra of these BLASGe1-ySiyO: xCe3+ phosphors effectively bridge the "cyan gap" within the 480-520 nm cyan-green emission region. Under 438 nm blue light excitation, the prepared BLASGO: Ce3+ phosphor exhibits broad-band cyan-green emission with an emission peak at 504 nm and a full width at half maximum (FWHM) of 103 nm, thereby significantly enhancing cyan emission while preserving green emission. More importantly, by substituting Ge4+ ions with smaller Si4+ ions, the internal quantum efficiency (IQE) and thermal stability of the phosphor are markedly improved due to the highly symmetrical rigid structure. The optimized BLASSO: Ce3+ phosphor demonstrates superior cyan-green emission performance with a high internal quantum efficiency of 93.28 % (an enhancement of 31.23 %) and thermal stability increased to 69.62 %. Based on the developed BLASSO: Ce3+ cyan-green phosphor, a high-performance full-visible-spectrum WLED device was successfully fabricated, featuring a high color rendering index (CRI or Ra, Ra = 93.4) and a low correlated color temperature (CCT = 2814 K).

Purpose: This work presents a series of (AgxCu1-x)0.7GaSe2 (0 ≤ x ≤ 1) powders synthesized via a solid-state reaction using the presynthesized ternary compounds Cu0.7GaSe2, Ag0.7GaSe2 and Ag0.7GaSe2. Experimental: A combination of X-ray diffraction (XRD) and Raman spectroscopy was used to establish that the solid solution region in this system is narrow and lies within the range of 0.8 ≤ x < 1. Conclusions: An investigation of low-temperature luminescence spectra and microwave photoconductivity decay kinetics revealed that single-phase samples exhibit increased lifetimes of photogenerated charge carriers. This is attributed to the replacement of deep charge carrier traps, such as selenium vacancies VSe, with shallower cationic copper vacancies associated with VCu and VSe-VCu

Antireflection coatings (ARCs) increase the absorption of light and, therefore, the conversion efficiency of solar cells. Mullite was chosen as the ARC material for a silicon (Si) solar cell and was synthesized by melting a charge consisting of a mixture of Al2O3 and SiO2 at a component concentration of 75 and 25 wt.

Environment-friendly Fe3+ ions as near-infrared (NIR) activators have garnered significant attention in intelligent NIR light sources; however, designing wavelength-tunable and outstanding thermal stability Fe3+-doped NIR luminescent materials remains a formidable challenge. In this study, we synthesized a novel garnet-structured NIR phosphor Y2CaAl4SiO12: Fe3+, Yb3+ and investigated its luminescent properties and energy transfer mechanisms. Under 270 nm ultraviolet light excitation, Y2CaAl4SiO12: Fe3+ demonstrates broadband NIR emission peaking at 803 nm, characterized by a full width at half maximum (FWHM) of 107 nm and exhibiting a remarkably high internal quantum efficiency (IQE) of 91.70 %, which is markedly superior to most reported Fe3+ doping NIR-emitting materials. Notably, the incorporation of Yb3+ ions facilitates an efficient energy transfer process from Fe3+ to Yb3+, which not only significantly broadens the emission spectrum but also enhances the thermal stability of Fe3+ (I-373 K/I-298 K = 59.24 %) compared to the singly Fe3+ doped sample (I-373 (K)/I-298 K = 45.30 %). Finally, the optimized Y2CaAl4SiO12: Fe3+, Yb3+ NIR phosphor exhibits promising potential for anti-counterfeiting applications.

The effect of substrate temperature and laser wavelength on the laser deposition of CdTe thin films has been studied. CdTe thin films synthesized on glass substrates have been studied using X-ray spectral microanalysis, X-ray diffraction and scanning electron microscopy. It has been shown that the ratio of elements in the CdTe thin films depends on both the substrate temperature and the laser wavelength. Specific features of the crystalline structure, phase composition and structural parameters of the synthesized CdTe films depending on the deposition process conditions (substrate temperature 100–400 °С, laser wavelength 600–1200 nm) have been revealed. Specifically, CdTe thin films deposited using laser radiation of wavelengths of 600 and 1200 nm have a cubic crystalline structure, while CdTe films obtained at a laser wavelength of 1064 nm have either a hexagonal structure or are a mixture of cubic and hexagonal phases, depending on the substrate temperature. At a low substrate temperature (100 °C) the films crystallize to a hexagonal structure, whereas at higher temperatures (200, 300 and 400 °C) the films are a polycrystalline mixture of cubic and hexagonal CdTe phases, growing predominantly along the [111]C direction. It has been shown that CdTe thin films on glass substrates have similar morphologies but different thicknesses, regardless of deposition conditions.

Near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) have found extensive applications in diverse fields including night vision, medical diagnostics, and plant lighting. However, designing NIR phosphors with large full width at half maximum (FWHM) and high thermal stability remains challenging. In this study, we developed a SrLu2Al3ScSiO12: Cr3+, Yb3+ phosphor (abbreviated as SLASSO: Cr3+, Yb3+) through a high-temperature solid-state reaction method. The SLASSO: Cr3+ samples exhibit two broad absorption bands in the blue light region (similar to 440 nm) and red light region (similar to 600 nm), confirming their can effective excitation by blue LED chips. Through precise control of the crystal field environment surrounding Cr3+ ions, the emission spectra of SLASSO: xCr(3+) phosphors demonstrate tunability from narrow-band to broadband emission, with emission peaks adjustable from 705 nm to 807 nm and FWHM expandable from 88 nm to 185 nm. SLASSO: 2 %Cr3+ phosphor demonstrates high quantum efficiency (75 %) and excellent thermal stability (95 %@423 K). By designing the energy transfer between Cr3+ and Yb3+, SLASSO: 2 %Cr3+, 1 %Yb3+ phosphors achieved both enhanced luminescence above 1000 nm and zero thermal quenching (103 %@423 K). A prototype NIR pc-LED device demonstrated remarkable performance, achieving an output power of 59.68 mW at 300 mA and a high photoelectric conversion efficiency of 30.76 % under 10 mA. These results highlight the SrLu2Al3ScSiO12: Cr3+, Yb3+ phosphor's potential for diverse applications, including non-destructive testing, medical diagnostics, anti-counterfeiting, and night vision technologies.

A set of AgxCu1 – xGaSe2 (0 ≤ x ≤ 1) solid solution powders has been prepared by solid-state synthesis. Using a combination of X-ray diffraction analysis and Raman spectroscopy, it has been found that the samples have a single-phase tetragonal structure (space group I-42d). It has been shown that their crystal lattice parameters do not follow Vegard’s law up to x ≈ 0.4. It has been revealed that the band gap of the samples also changes nonlinearly: initially it decreases and then increases. Studies of the low-temperature luminescence and microwave photoconductivity decay spectra have shown that a set of samples with x of 0 to 0.4 and further in the region with x > 0.4 is characterized by an increase in the photogenerated current carrier lifetime in AgxCu1 – xGaSe2 powders. The observed effect is apparently attributed to the replacement of deep charge carrier traps, such as selenium vacancies, by shallower cation vacancies.

Zero-valent iron nanoparticles were synthesized by the sol-gel method using its chloride salt (FeCl3‧6H2O) and sodium borohydride (NaBH4) as a reducing agent. A special feature of the synthesis is the relatively low production temperature – 100 °C. X-ray diffraction analysis revealed an almost single-phase state of the resulting material with a cubic structure. Microphotographs of the samples indicate the nanodispersed state of iron particles in the form of small spherical and large rod-shaped particles with a transverse size of up to 10 nm and an average length of 50 nm. Analysis of the data obtained during the research showed that the proposed sol-gel method is a simple and controlled method for the synthesis of monodisperse iron nanoparticles.

This work describes the production of single crystals of the semiconducting quaternary compound Cu2ZnGeSe4 using a gas chemical method in which iodine was used as a transporter. For all the synthesized samples, their phase state, crystal structure syngony and lattice constants were refined. The unit cell of the studied compound is characterized by tetragonal symmetry. The transmission spectrum was applied to calculate the band gap, which is depicted as temperature function in 20-300 K range. It was fixed that the band gap increases by 12% with decreasing temperature.

We report the insertion of a new intermediate layer, a multi-layered graphitic carbon (MLGC), at Mo/CZTS interface and its impact on the structural and morphological characteristics of the back interface and absorber. MLGC was synthesized directly on Mo-coated SLG under a gas mixture flow of H2/CH4 at 550 °C via PECVD for 3 and 5 h. CZTS precursors were prepared on SLG/Mo and MLGC-coated SLG/Mo in a hybrid physical vapor deposition system, including evaporation and sputtering techniques, then subjected to sulfurization at 550 °C. The sheet resistance of back contact, microstructural parameters of the absorbers, the distributions of C and constituent elements were investigated. The diffraction peaks of the hexagonal Mo2C indicated the reaction between the C and Mo before the MLGC’s growth. Raman analysis confirmed the formation of the MLGC during the long deposition time after the Mo2C formation. With the addition of MLGC, the sheet resistance of the back contact decreased from 2 to 0.5 Ω/sq, and the crystallite size of the absorbers improved. Raman spectra from the interface exhibited that MoS2 peaks’ intensities significantly reduced with increasing the growth time. This implied that the 5 h-deposited MLGC was more effective in blocking the reaction between Mo and S. The absorbers with the MLGC had more uniform surface morphologies, densely packed grains, and fewer secondary phases. FIB analysis revealed the separation of the absorber with the 5 h-deposited MLGC into two parts due to C impurity. More C diffusion into the absorber for this sample was confirmed by SIMS.

The solid-phase method was applied to synthesize Cu2-delta BaSnS4 (0 <=delta <= 0.4) polycrystalline powders. The lattice parameters were refined. It was shown that the crystal structure parameters changed. For the first time, Raman spectra were experimentally obtained for copper-deficient samples. It was found that some difference in the position of major peaks is due to the Cu2-delta BaSnS4 structure changing with increasing delta, as well as a partial valence change in tin or copper atoms. Using X-ray photoelectron spectroscopy, it was shown that when going from Cu2BaSnS4 to Cu1.6BaSnS4, there was no change in the valence state of copper, but the valence state of tin particularly changed. The lifetimes of the current carriers in the synthesized samples were significantly less than 10 ns.

Nickel nanoparticles were synthesized at room temperature by a one-step method of chemical reduction of Ni ions from NiCl2∙6H2O using NaBH4. The microstructure of the nanoparticles was studied by x-ray diffraction, Raman spectroscopy, and scanning and transmission electron microscopy. An analysis of x-ray diffraction and Raman spectroscopy data showed that the obtained nanoparticles had the cubic metallic Ni structure with a crystallite size (coherent scattering region) of 3–6 nm. Studies of the morphology indicated that the Ni nanoparticles were spherical in shape and in contact with each other to form large agglomerates of nanograins.

In this work, the optical properties of nanocrystalline CdS films in the initial state and after ion-plasma treatment have been studied. The chemical bath deposition technique was used to prepare CdS films with thickness 80-115 nm on glass substrates. The ion-plasma treatment was carried out in argon plasma in a high-density low-pressure radio frequency inductively coupled plasma reactor at an argon ion energy of 25 eV for 30-50 s. It has been established that ion-plasma treatment leads to a decrease in film thickness by 10-15% of the initial one and the formation of new nanostructures on its surface. The results showed that the sizes of coherent scattering regions during plasma treatment decreased for a series of studied samples from 8.2-10.0 nm to 6.3-7.7 nm. This led to an increase in the band gap energy of the for nanocrystalline CdS films from 2.53-2.78 eV to 2.95-3.11 eV.

In the present study, the effect of annealing and Ar-plasma treatment on structural, morphological and optical properties of thermally evaporated β -In 2 S 3 thin films has been investigated. During Ar-plasma treatment, some interesting results were observed that an array of metallic indium nanostructures was formed over In 2 S 3 film surface with quasi-spherical or spread droplet shapes of an average size of 20–100 nm in the lateral direction and a height of less than 70 nm. Here, the Ar-plasma treatment serves as a new strategy for the self-formation of metallic indium nanostructures over the film surface. Further, the optical absorption of In 2 S 3 films has been enhanced from 10 4 to 10 7 cm −1 while the optical band gap energy decreased from 2.71 eV to 2.50 eV after Ar-plasma treatment. The metallic nanostructures loaded on semiconductor surface can act as an electron trap that can effectively prevent the recombination of photo-generated electron-hole pairs.

A two-step process was used to prepare Cu2SnS3 films in this study: first, precursor stacks were deposited using a magnetron sputtering technique, and then the stacks were annealed in sulfur-containing atmo-sphere at various times. Utilizing a variety of characterization techniques, it was thoroughly examined how sulfurization time affected the films' structural, morphological, optical, and electrical characteristics. X-ray diffraction and Raman spectroscopy measurements indicated that two structural polymorphs (tetragonal and monoclinic) of Cu2SnS3 co-existed in the films. Surface and cross-sectional images obtained by scanning electron microscopy showed that the microstructures of the films were entirely changed to well-grown crystal structures at 30 min and 40 min sulfurization times. In2S3/Cu2SnS3 stacks were prepared by the deposition of In2S3 films on the absorber layers sulfurized for 30 and 40 min by RF magnetron sputtering method. The fabrication of Ni/Al/Ni/AZO/i:ZnO/In2S3/Cu2SnS3/Mo/SLG-structured devices was done using both thermally annealed and non-annealed In2S3/Cu2SnS3 stacks. Secondary ion mass spectroscopy studies of the devices revealed that the indium diffused from In2S3 layer into the Cu2SnS3 absorber to a certain depth. The efficiency values of the devices were found to have been slightly enhanced with the annealing of the In2S3/Cu2SnS3 stacks. The solar cell with the maximum efficiency (eta) of 3.12 %, open-circuit voltage (VOC) of 0.265 mV, short-circuit current (JSC) of 37.90 mA/cm2 , and fill factor (FF) of 0.31 was produced by thermally annealed In2S3/Cu2SnS3 stack with an absorber layer sulfurized for 40 min.(c) 2023 Elsevier B.V. All rights reserved.

Single crystals of Cu2ZnGeSe4 and Cu2ZnGeS4 solid solutions were developed and successfully obtained using the chemical vapor transfer method, with iodine acting as a transporter. The structure, compositional dependences of lattice parameters, pycnometric and X-ray densities and microhardness were determined. The chemical composition determined by the X-ray microanalysis satisfactorily corresponds to the nominal one with a tolerance of ±5 %. The XRD analysis showed that all the obtained compounds and their solid solutions have unit cell described by tetragonal symmetry. The attice parameters were found to be а = 5.342 ± 0.005 Å, с = 10.51 ± 0.01 Å for the Сu2ZnGeS4 compound and а = 5.607 ± 0.005 Å, с = 11.04 ± 0.01 Å for the Cu2ZnGeSe4, respectively. Structural studies confirmed the validity of the Vegard's law in relation to the obtained samples. The pycnometric densities of ∼4.28 g/cm3 for the Cu2ZnGeS4 and ∼5.46 g/cm3 for the Cu2ZnGeSe4 were found to be slightly less than their X-ray densities of ∼4.32 g/cm3 and ∼5.52 g/cm3, respectively. The maximum microhardness of ∼398 kg/mm2 for these solid solutions corresponds to x = 0.60. The melt point of the solid solutions increases from ∼1180 °C for the Сu2ZnGeSe4 up to ∼1400 °C for the Сu2ZnGeS4. Based on X-ray fluorescence analysis and DTA data, the phase diagram of the Cu2ZnGeSe4-Cu2ZnGeS4 system was constructed. Analysis of the obtained diagram indicates its first type according to Rozbom's classification.

We present the results of the study of the microstructure, X-ray diffraction and Raman scattering spectra of Cu2SnS3 (CTS) films synthesized at 500 o C by the sulfurization of SnCu stacked metal precursors with different annealing time. The results indicate that sulfurization time has a great influence on both composition and morphology of the film. It is shown that the process of formation of a single-phase CTS compound with a monoclinic structure and composition close to stoichiometry is completed for a synthesis time of 60 - 80 min. With an increase in the time of synthesis to 120 min, the preservation of the monoclinic structural modification of the material is observed, accompanied by a shift in the stoichiometric composition, namely copper enrichment, material delamination and degradation of microstructural characteristics. As a result, it was found that the most optimal conditions for the synthesis of a single-phase Cu2SnS3 compound of a monoclinic structure are the temperature 500 o С with the duration of the sulfurization process from 60 to 80 min.

The impact of discrete vacuum thermal evaporation (DVTE)-produced CdTe thin films after thermal annealing and CdCl2 treatment is discussed in the present article. As a result of simultaneous DVTE of CdCl2 and CdTe, CdCl2 was added straightly into the bulk of the formed CdTe film at the 270 degrees C substrate temperature in a single procedure. The DVTE approach deposits CdTe thin films with a high crystalline structure, which can be utilized effectively for the production of high efficiency solar cell applications, according to the results of X-ray diffraction, scanning electron microscopy with focused ion beam, transmission electron microscopy, and atomic force microscopy measurements.

Single phase and highly transparent ZnO:Tb films with a Tb concentration from 0.41 at