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Article Citation - WoS: 4Citation - Scopus: 3Exploring the Thermal Stability of Sb2se3 for Potential Applications Through Advanced Thermal Analysis Methods(Amer Chemical Soc, 2025) Altuntas, Gozde; Isik, Mehmet; Surucu, Gokhan; Parlak, Mehmet; Surucu, OzgeAntimony selenide (Sb2Se3) is a promising material for energy applications, including photovoltaics, thermoelectrics, and photodetectors, due to its favorable electronic properties, availability, and low toxicity. However, its thermal stability, crucial for device efficiency and reliability, has been less explored, leaving a gap in understanding its high-temperature suitability. This study evaluates the thermal stability of Sb2Se3 using thermogravimetric analysis (TGA), differential thermal analysis (DTA), and differential scanning calorimetry (DSC). The results show that Sb2Se3 remains stable up to 500 degrees C, with two significant weight loss stages: 1.75% between 500 and 610 degrees C, and 3.50% between 610 and 775 degrees C, indicating decomposition processes. Activation energies for the decomposition phases were determined as 121.8 and 57.2 kJ/mol using the Coats-Redfern method. Additionally, an endothermic phase transition was observed between 599 and 630.6 degrees C via DSC analysis. These findings demonstrate Sb2Se3's potential for high-temperature energy applications, providing essential insights for optimizing its use in solar cells, thermoelectric devices, and other technologies.Article Citation - WoS: 9Citation - Scopus: 14Bifunctional Praseodymium-Doped Sns2 Thin Films for Photocatalytic and Antibacterial Applications(Elsevier, 2024) Ech-Chergui, Abdelkader Nebatti; Bennabi, Farid; Isik, Mehmet; Khane, Yasmina; Garcia, Francisco Jose Garcia; Kadari, Ali Sadek; Amrani, BouhalouaneThis paper introduces a novel application of bifunctional Pr-doped SnS2 thin films, demonstrating their efficacy in both photocatalytic degradation of dye and antibacterial activities. The thin films were fabricated using an eco-friendly spray-coated method, encompassing undoped and Pr-doped SnS2 variations. The study comprehensively examines the structural, morphological, chemical, photocatalytic, and antibacterial characteristics of these films. The crystal structure of both undoped and Pr-doped SnS2 thin films exhibited hexagonal patterns, prominently favouring the growth in (1 0 1) orientation. Notably, an increase in crystallite size was observed with higher levels of Pr-doping. Raman spectroscopy analysis highlighted a distinct peak at 315 cm -1, corresponding to the A1 g vibrational mode associated with Sn-S bonds along the c-axis of the structure. Employing X ray Photoelectron Spectroscopy (XPS), the presence of essential components - Sn, S, and Pr - within the fabricated thin films was confirmed, consistent with experimental values of undoped and Pr -doped SnS2-x compositions. Importantly, the XPS analysis confirmed the integration of the Pr3+ oxidation state within Pr -doped SnS2 films. The photocatalytic degradation and antibacterial activities of the films were investigated. Notably, the photocatalytic potential of the synthesized materials against Congo Red exhibited a direct correlation with the Pr3+ doping percentage, indicating enhanced pollutant degradation with increasing doping levels. Similarly, the antibacterial performance against Escherichia coli displayed improvement with increasing Pr -doping content, highlighting the promising antimicrobial capabilities of the films. This study presents an innovative avenue to address both organic pollutant degradation and microbial control. By harnessing the attributes of Pr -doped SnS2 thin films, this research introduces a promising strategy for sustainable material applications in environmental purification and improvement in public health.Article Citation - WoS: 24Citation - Scopus: 23Revealing the Effects of Defect States on the Nonlinear Absorption Properties of the Tlinsse and Tl2in2< Crystals in Near-Infrared Optical Limiting Applications(Amer Chemical Soc, 2024) Dogan, Anil; Karatay, Ahmet; Isik, Mehmet; Yildiz, Elif Akhuseyin; Gasanly, Nizami Mamed; Elmali, AyhanThe present study represents the effect of defect states on the nonlinear absorption and optical limiting performances of TlInSSe and Tl2In2S3Se single crystals with near-infrared excitations. The band gap energies were 2.2 and 2.22 eV, and the Urbach energies were 0.049 and 0.034 eV for TlInSSe and Tl2In2S3Se, respectively. The trapping time of localized defect states was found to be 8 ns by femtosecond transient absorption measurements. The analysis of open-aperture Z-scan data depends on two different fitting models to determine the effect of defect states on the nonlinear absorption (NA) properties of the studied crystals. Model 1 only considers two-photon absorption (TPA), while model 2 includes one-photon absorption (OPA), TPA, and free carrier absorption (FCA). The NA coefficients (ss(eff)) obtained from model 2 are higher than the values (ss) obtained from model 1 at the same intensities, revealing that defect states contribute to NA through OPA. The optical limiting properties of the TlInSSe and Tl2In2S3Se crystals were examined under 1064 nm wavelength excitation. The limiting thresholds were found to be 1.16 and 0.27 mJ/cm(2) at 29.8 GW/m(2) and 99.5 GW/m(2) input intensities, respectively. The results show that TlInSSe and Tl2In2S3Se crystals have promising potential for near-infrared optical limiting applications.Article Citation - WoS: 8Citation - Scopus: 9Revealing Photoluminescence and Nonlinear Optical Absorption Characteristics of Pbmo0.75w0.25< Single Crystal for Optical Limiting Applications(Iop Publishing Ltd, 2024) Dogan, Anil; Karatay, Ahmet; Isik, Mehmet; Yildiz, Elif Akhuseyin; Gasanly, Nizami; Elmali, AyhanNonlinear absorption properties of PbMo0.75W0.25O4 single crystal fabricated by the Czochralski method were studied. The band gap energy of the crystal was determined as 3.12 eV. Urbach energy which represents the defect states inside the band gap was found to be 0.106 eV. PbMo0.75W0.25O4 single crystal has a broad photoluminescence emission band between 376 and 700 nm, with the highest emission intensity occurring at 486 nm and the lowest intensity peak at 547 nm, depending on the defect states. Femtosecond transient absorption measurements reveal that the lifetime of localized defect states is found to be higher than the 4 ns pulse duration. Open aperture (OA) Z-scan results demonstrate that the PbMo0.75W0.25O4 single crystal exhibits nonlinear absorption (NA) that includes two-photon absorption (TPA) as the dominant mechanism at the 532 nm excitations corresponding to 2.32 eV energy. NA coefficient (beta(eff)) increased from 7.24 x 10(-10) m W-1 to 8.81 x 10(-10) m W-1 with increasing pump intensity. At higher intensities beta(eff) tends to decrease with intensity increase. This decrease is an indication that saturable absorption (SA) occurred along with the TPA, called saturation of TPA. The lifetime of the defect states was measured by femtosecond transient absorption spectroscopy. Saturable absorption behavior was observed due to the long lifetime of the localized defect states. Closed aperture (CA) Z-scan trace shows the sign of a nonlinear refractive index. The optical limiting threshold of PbMo0.75W0.25O4 single crystal at the lowest intensity was determined as 3.45 mJ/cm(2). Results show that the PbMo0.75W0.25O4 single crystal can be a suitable semiconductor material for optical limiting applications in the visible region.