Pub Date : 2025-02-01DOI: 10.1016/j.omx.2025.100400
Marina Romanova , Sergii Chertopalov , Yuri Dekhtyar , Ladislav Fekete , Ján Lančok , Michal Novotný , Petr Pokorný , Anatoli I. Popov , Hermanis Sorokins , Aleksandr Vilken
The charge trapping phenomenon in the SiO2 layer of Si/SiO2 substrates during the electron beam deposition of CaF2 thin films of varying thicknesses (50–277 nm) was studied. Photoelectron emission (PE) spectroscopy was employed to analyze electron trapping mechanisms induced by the deposition process. Distinct peaks corresponding to electron traps in the SiO2 layer were identified in the PE spectra of CaF2 films. The intensity of these peaks varied with the film thickness and the accumulated electron irradiation dose. The study also investigated the relaxation of the PE spectra in both vacuum and air environments. In a vacuum, the PE peaks and integrated PE intensity remained stable for at least 24 h for CaF2 films of all thicknesses. When exposed to air, the PE peaks persisted for several days in films 125 nm thick or thinner but relaxed within several hours in 277 nm films. This rapid relaxation was attributed to a relatively high irradiation dose (about 2.5 mC) obtained during the fabrication of the 277 nm film, leading to an increased concentration of ionized F centers at the SiO2–CaF2 interface and the formation of (O2–-VA) centers upon air exposure. The relaxation of the PE spectrum intensity was attributed to electron transfer from SiO2 traps to (O2–-VA) centers. Furthermore, the possibility of a 260 nm electron escape depth for CaF2 material was confirmed.
{"title":"Charge trapping in SiO2 substrate during electron beam deposition of CaF2 thin films of different thicknesses","authors":"Marina Romanova , Sergii Chertopalov , Yuri Dekhtyar , Ladislav Fekete , Ján Lančok , Michal Novotný , Petr Pokorný , Anatoli I. Popov , Hermanis Sorokins , Aleksandr Vilken","doi":"10.1016/j.omx.2025.100400","DOIUrl":"10.1016/j.omx.2025.100400","url":null,"abstract":"<div><div>The charge trapping phenomenon in the SiO<sub>2</sub> layer of Si/SiO<sub>2</sub> substrates during the electron beam deposition of CaF<sub>2</sub> thin films of varying thicknesses (50–277 nm) was studied. Photoelectron emission (PE) spectroscopy was employed to analyze electron trapping mechanisms induced by the deposition process. Distinct peaks corresponding to electron traps in the SiO<sub>2</sub> layer were identified in the PE spectra of CaF<sub>2</sub> films. The intensity of these peaks varied with the film thickness and the accumulated electron irradiation dose. The study also investigated the relaxation of the PE spectra in both vacuum and air environments. In a vacuum, the PE peaks and integrated PE intensity remained stable for at least 24 h for CaF<sub>2</sub> films of all thicknesses. When exposed to air, the PE peaks persisted for several days in films 125 nm thick or thinner but relaxed within several hours in 277 nm films. This rapid relaxation was attributed to a relatively high irradiation dose (about 2.5 mC) obtained during the fabrication of the 277 nm film, leading to an increased concentration of ionized F centers at the SiO<sub>2</sub>–CaF<sub>2</sub> interface and the formation of (O<sup>2–</sup>-V<sub>A</sub>) centers upon air exposure. The relaxation of the PE spectrum intensity was attributed to electron transfer from SiO<sub>2</sub> traps to (O<sup>2–</sup>-V<sub>A</sub>) centers. Furthermore, the possibility of a 260 nm electron escape depth for CaF<sub>2</sub> material was confirmed.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100400"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.omx.2024.100397
G. Gordillo , O.G. Torres , C.A. Celis , M. Reinoso , J I Clavijo
Toxicity and poor stability remain major barriers to large-scale production of hybrid organic-inorganic lead halide perovskite solar cells. Considering the isoelectronic nature of lead (II) and bismuth (III) ions, stable and non-toxic alternatives for developing photovoltaic devices could potentially be found. Rb3Bi2I9 perovskite films inherently suffer from unavoidable pinhole defects and poor surface morphology, which limit device performance. In this work we explored a dual-source thermal sequential evaporation approach to growth uniform and pinhole-free morphology of Rb3Bi2I9 polycrystalline thin films. The influence of post-deposition annealing in a high-pressure N2 atmosphere on the structural, optical, morphological, and electronic properties of the resulting films was studied experimentally using X-ray diffraction (XRD), optical spectrophotometry, scanning electron microscopy (SEM), and computationally via Density Functional Theory (DFT) calculations. The results revealed that post deposition annealing significantly improves both the morphology and degradation processes of Rb3Bi2I9 films, when they are exposed to environmental conditions for long periods of time.
{"title":"Evaluation of the optical, structural, morphological and electronic properties of Rb3Bi2I9 Perovskites films prepared by Sequential Evaporation","authors":"G. Gordillo , O.G. Torres , C.A. Celis , M. Reinoso , J I Clavijo","doi":"10.1016/j.omx.2024.100397","DOIUrl":"10.1016/j.omx.2024.100397","url":null,"abstract":"<div><div>Toxicity and poor stability remain major barriers to large-scale production of hybrid organic-inorganic lead halide perovskite solar cells. Considering the isoelectronic nature of lead (II) and bismuth (III) ions, stable and non-toxic alternatives for developing photovoltaic devices could potentially be found. Rb<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub> perovskite films inherently suffer from unavoidable pinhole defects and poor surface morphology, which limit device performance. In this work we explored a dual-source thermal sequential evaporation approach to growth uniform and pinhole-free morphology of Rb<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub> polycrystalline thin films. The influence of post-deposition annealing in a high-pressure N2 atmosphere on the structural, optical, morphological, and electronic properties of the resulting films was studied experimentally using X-ray diffraction (XRD), optical spectrophotometry, scanning electron microscopy (SEM), and computationally via Density Functional Theory (DFT) calculations. The results revealed that post deposition annealing significantly improves both the morphology and degradation processes of Rb<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub> films, when they are exposed to environmental conditions for long periods of time.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100397"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.omx.2024.100388
Dana S. Yerimbetova , Marina Konuhova , Artem L. Kozlovskiy , Umitali N. Tuichiyev
The aim of this research is to study the prospects of using the proposed methods of optical UV spectroscopy and X-ray diffractometry to determine the radiation density of the daughter products of radon decay - α-particles recorded using polymer track detectors. This paper presents the results of experiments on detecting the daughter products of radon decay - α-particles in a room on various floors for a fairly long time (within 6 months), the choice of which made it possible to determine not only the concentration dependences (growth in the density of registered α-particles) over time, but also to determine the lower limit for recording changes in the optical spectra of film detectors used to register α-particles. During the experiments, good convergence of the results of structural changes determined by optical spectroscopy and X-ray diffraction methods was established. These changes are caused by the processes of interaction of α-particles with a polymer detector, characterized by deformation distortion of the molecular chains of the polymer, leading to the formation of defects that affect changes in optical and electron density. The proposed methods were used to determine the connection between the interaction processes of α-particles with the molecular structure of polymer films used as detectors. It was determined that the most significant changes are observed at densities of registered α-particles above 104 cm−2, the value of which is the threshold value for identification of radon decay products using film detectors without chemical etching.
{"title":"Study of the application prospects of film detectors for estimation of α-radiation density","authors":"Dana S. Yerimbetova , Marina Konuhova , Artem L. Kozlovskiy , Umitali N. Tuichiyev","doi":"10.1016/j.omx.2024.100388","DOIUrl":"10.1016/j.omx.2024.100388","url":null,"abstract":"<div><div>The aim of this research is to study the prospects of using the proposed methods of optical UV spectroscopy and X-ray diffractometry to determine the radiation density of the daughter products of radon decay - α-particles recorded using polymer track detectors. This paper presents the results of experiments on detecting the daughter products of radon decay - α-particles in a room on various floors for a fairly long time (within 6 months), the choice of which made it possible to determine not only the concentration dependences (growth in the density of registered α-particles) over time, but also to determine the lower limit for recording changes in the optical spectra of film detectors used to register α-particles. During the experiments, good convergence of the results of structural changes determined by optical spectroscopy and X-ray diffraction methods was established. These changes are caused by the processes of interaction of α-particles with a polymer detector, characterized by deformation distortion of the molecular chains of the polymer, leading to the formation of defects that affect changes in optical and electron density. The proposed methods were used to determine the connection between the interaction processes of α-particles with the molecular structure of polymer films used as detectors. It was determined that the most significant changes are observed at densities of registered α-particles above 10<sup>4</sup> cm<sup>−2</sup>, the value of which is the threshold value for identification of radon decay products using film detectors without chemical etching.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100388"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.omx.2024.100390
S.G. Nedilko , O. Chukova , A. Dorofieieva , S.A. Nedilko , V. Shcherbatskyi , T. Voitenko , M. Etter , H.S. Rahimi Mosafer , W. Paszkowicz , Y. Zhydachevskyy , A. Suchocki
This work aims to clarify the relationship between the optical, particularly luminescent, characteristics of the La1-x-ySmxCayVO4-δ powder nanosized compounds with their phase composition and concentration of dopants. According to the high-accuracy XRD data, the samples are a mixture of monoclinic and tetragonal crystal phases. The diffuse reflection and photoluminescence (PL) spectra were measured and analyzed including spectral distributions and intensity ratios of the PL bands, the positions and half-widths of envelopes of the groups of lines in the PL spectra of Sm3+ ions. Estimated from the diffuse reflection data the band gap values are 3.85, and 3.82, 3.75, 3.78 eV for the samples with x = 0.1, y = 0, and (x, y) = 0.05, 0.10, 0.15, respectively. The PL excitation spectra of the La1-x-ySmxCayVO4-δ nanoparticles consist of both the wide UV wavelength band (260–360 nm) caused by transition in the VO43− molecular groups and in a set of narrow lines caused by inner f-f transitions in the Sm3+ ions (spectral range 350–520 nm). The PL spectra of the La1-x-ySmxCayVO4-δ nanoparticles contain four groups of lines (I – IV) resulting from the 4G5/2 → 6H5/2, 6H7/2, 6H9/2, and 6H11/2 transitions, respectively, in the inner f shell of the Sm3+ ions. The concentration behavior of the Sm3+ ions PL characteristics is related to the evaluation of the phase composition of La1-x-ySmxCayVO4-δ samples. It was found that the changes of the Rlum = I(III)/I(I), where I(III) and I(I) are the integrated intensities of the corresponding groups of lines, can be related to the phase composition of the La1-x-ySmxCayVO4-δ compounds. Developed in this work the combined way of structural and optical data analysis may be useful in designing other multiphase phosphor systems containing Sm3+ ions.
{"title":"Evolution of phase composition and luminescent characteristics of the La1-x-ySmxCayVO4-δ nanocrystalline phosphor","authors":"S.G. Nedilko , O. Chukova , A. Dorofieieva , S.A. Nedilko , V. Shcherbatskyi , T. Voitenko , M. Etter , H.S. Rahimi Mosafer , W. Paszkowicz , Y. Zhydachevskyy , A. Suchocki","doi":"10.1016/j.omx.2024.100390","DOIUrl":"10.1016/j.omx.2024.100390","url":null,"abstract":"<div><div>This work aims to clarify the relationship between the optical, particularly luminescent, characteristics of the La<sub>1-x-y</sub>Sm<sub>x</sub>Ca<sub>y</sub>VO<sub>4-δ</sub> powder nanosized compounds with their phase composition and concentration of dopants. According to the high-accuracy XRD data, the samples are a mixture of monoclinic and tetragonal crystal phases. The diffuse reflection and photoluminescence (PL) spectra were measured and analyzed including spectral distributions and intensity ratios of the PL bands, the positions and half-widths of envelopes of the groups of lines in the PL spectra of Sm<sup>3+</sup> ions. Estimated from the diffuse reflection data the band gap values are 3.85, and 3.82, 3.75, 3.78 eV for the samples with x = 0.1, y = 0, and (x, y) = 0.05, 0.10, 0.15, respectively. The PL excitation spectra of the La<sub>1-x-y</sub>Sm<sub>x</sub>Ca<sub>y</sub>VO<sub>4-δ</sub> nanoparticles consist of both the wide UV wavelength band (260–360 nm) caused by transition in the VO<sub>4</sub><sup>3−</sup> molecular groups and in a set of narrow lines caused by inner <em>f-f</em> transitions in the Sm<sup>3+</sup> ions (spectral range 350–520 nm). The PL spectra of the La<sub>1-x-y</sub>Sm<sub>x</sub>Ca<sub>y</sub>VO<sub>4-δ</sub> nanoparticles contain four groups of lines (I – IV) resulting from the <sup>4</sup>G<sub>5/2</sub> → <sup>6</sup>H<sub>5/2</sub>, <sup>6</sup>H<sub>7/2</sub>, <sup>6</sup>H<sub>9/2</sub>, and <sup>6</sup>H<sub>11/2</sub> transitions, respectively, in the inner <em>f</em> shell of the Sm<sup>3+</sup> ions. The concentration behavior of the Sm<sup>3+</sup> ions PL characteristics is related to the evaluation of the phase composition of La<sub>1-x-y</sub>Sm<sub>x</sub>Ca<sub>y</sub>VO<sub>4-δ</sub> samples. It was found that the changes of the R<sub>lum</sub> = I<sub>(III)</sub>/I<sub>(I)</sub>, where I<sub>(III)</sub> and I<sub>(I)</sub> are the integrated intensities of the corresponding groups of lines, can be related to the phase composition of the La<sub>1-x-y</sub>Sm<sub>x</sub>Ca<sub>y</sub>VO<sub>4-δ</sub> compounds. Developed in this work the combined way of structural and optical data analysis may be useful in designing other multiphase phosphor systems containing Sm<sup>3+</sup> ions.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100390"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.omx.2024.100392
Kuat K. Kumarbekov , Askhat B. Kakimov , Zhakyp T. Karipbayev , Murat T. Kassymzhanov , Mikhail G. Brik , Chong-geng Ma , Michał Piasecki , Yana Suchikova , Meldra Kemere , Marina Konuhova
This study explores the synthesis and luminescent properties of europium-doped gallium oxide (Ga₂O₃:Eu) ceramics fabricated via electron beam-assisted synthesis (EBAS) at 1.4 MeV. The resulting Ga₂O₃:Eu ceramics exhibit a nanocrystalline structure with an average crystallite size of ∼30 nm, high crystallinity, and minimal lattice strain (<0.5 %). Luminescence analysis from 4 K to 300 K reveals both intrinsic and europium-induced emissions. While intrinsic Ga₂O₃ emission exhibits thermal quenching above 100 K, Eu³⁺-related emissions, notably the 611 nm red emission, show thermal stability, retaining ∼90 % of their intensity at 300 K. Additionally, a novel low-temperature emission peak at 1.74 eV, potentially associated with electron beam-induced defects, was detected, meriting further exploration. These findings indicate that Ga₂O₃:Eu ceramics synthesized via EBAS hold promise for optoelectronic, radiation detection, and high-temperature applications, given their rapid production and enhanced thermal stability.
{"title":"Temperature-dependent luminescence of europium-doped Ga₂O₃ ceramics","authors":"Kuat K. Kumarbekov , Askhat B. Kakimov , Zhakyp T. Karipbayev , Murat T. Kassymzhanov , Mikhail G. Brik , Chong-geng Ma , Michał Piasecki , Yana Suchikova , Meldra Kemere , Marina Konuhova","doi":"10.1016/j.omx.2024.100392","DOIUrl":"10.1016/j.omx.2024.100392","url":null,"abstract":"<div><div>This study explores the synthesis and luminescent properties of europium-doped gallium oxide (Ga₂O₃:Eu) ceramics fabricated via electron beam-assisted synthesis (EBAS) at 1.4 MeV. The resulting Ga₂O₃:Eu ceramics exhibit a nanocrystalline structure with an average crystallite size of ∼30 nm, high crystallinity, and minimal lattice strain (<0.5 %). Luminescence analysis from 4 K to 300 K reveals both intrinsic and europium-induced emissions. While intrinsic Ga₂O₃ emission exhibits thermal quenching above 100 K, Eu³⁺-related emissions, notably the 611 nm red emission, show thermal stability, retaining ∼90 % of their intensity at 300 K. Additionally, a novel low-temperature emission peak at 1.74 eV, potentially associated with electron beam-induced defects, was detected, meriting further exploration. These findings indicate that Ga₂O₃:Eu ceramics synthesized via EBAS hold promise for optoelectronic, radiation detection, and high-temperature applications, given their rapid production and enhanced thermal stability.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100392"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.omx.2025.100401
Ibrahim Oksuz , Sabin Neupane , Yanfa Yan , Lei R. Cao
A nuclear photovoltaic battery uses scintillator to convert radiation into visible light, which is then collected by a photovoltaic (PV) cell to generate electricity. If the radiation is gamma-rays emitted from external sources, the battery may also be referred as gammavoltaic battery. In this study, a polycrystalline CdTe solar cell was optically coupled with a 2.0 cm × 2.0 cm × 1.0 cm Gadolinium Aluminum Gallium Garnet (GAGG) scintillator, and the resulting device was tested using intense gamma radiation fields from a Cs-137 (1.5 kRad/h) and a Co-60 (10 kRad/h) irradiator. Measurements with Cs-137 provided a maximum power output (Pmax) of ∼288 nW, with a short-circuit current density (Jsc) of ∼1.22 μA/cm2 and an open-circuit voltage (Voc) of ∼0.34 V. In contrast, Co-60 irradiator gave a Pmax of 1.5 μW, with a Jsc of ∼4.73 μA/cm2 and a Voc of ∼0.38 V. The CdTe was also paired with a Lutetium-Yttrium Oxyorthosilicate (LYSO) crystal and tested with the Cs-137 source. The experiment presents a scalable option to reach to higher power outputs by harvesting gamma radiation fields in many cases where high radiation field demands heavy shielding and is often regarded as unwanted waste.
{"title":"Scintillator based nuclear photovoltaic batteries for power generation at microwatts level","authors":"Ibrahim Oksuz , Sabin Neupane , Yanfa Yan , Lei R. Cao","doi":"10.1016/j.omx.2025.100401","DOIUrl":"10.1016/j.omx.2025.100401","url":null,"abstract":"<div><div>A nuclear photovoltaic battery uses scintillator to convert radiation into visible light, which is then collected by a photovoltaic (PV) cell to generate electricity. If the radiation is gamma-rays emitted from external sources, the battery may also be referred as gammavoltaic battery. In this study, a polycrystalline CdTe solar cell was optically coupled with a 2.0 cm × 2.0 cm × 1.0 cm Gadolinium Aluminum Gallium Garnet (GAGG) scintillator, and the resulting device was tested using intense gamma radiation fields from a Cs-137 (1.5 kRad/h) and a Co-60 (10 kRad/h) irradiator. Measurements with Cs-137 provided a maximum power output (P<sub>max</sub>) of ∼288 nW, with a short-circuit current density (J<sub>sc</sub>) of ∼1.22 μA/cm<sup>2</sup> and an open-circuit voltage (V<sub>oc</sub>) of ∼0.34 V. In contrast, Co-60 irradiator gave a P<sub>max</sub> of 1.5 μW, with a J<sub>sc</sub> of ∼4.73 μA/cm<sup>2</sup> and a V<sub>oc</sub> of ∼0.38 V. The CdTe was also paired with a Lutetium-Yttrium Oxyorthosilicate (LYSO) crystal and tested with the Cs-137 source. The experiment presents a scalable option to reach to higher power outputs by harvesting gamma radiation fields in many cases where high radiation field demands heavy shielding and is often regarded as unwanted waste.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100401"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.omx.2024.100387
Dmitriy I. Shlimas , Daryn B. Borgekov , Artem L. Kozlovskiy
The aim of this study is to determine the differences in the damaged layer degradation kinetics in two-phase lithium-containing ceramics based on Li2ZrO3 and Li4SiO4 compounds in the case of irradiation with protons and helium ions, simulating the gas swelling and blistering processes, as well as the accumulation of radiolysis products in the damaged layer. During the conducted studies it was established that in the case of proton irradiation, the dominant role at fluences of 1015–1017 cm−2 is played by oxygen vacancies, the change in the concentration of which upon reaching critical values causes a decrease in the thermophysical properties, and disordering of the damaged layer. In this case, the accumulation of radiolysis products in the form of HC2 – and Zr3+ -defects in the structure of the damaged layer is observed at fluences of 5 × 1017 cm−2, while when irradiated with He2+ ions, the formation of these types of HC2 – and Zr3+ -defects is observed at a fluence of 1017 cm−2. Comparison of the concentration dependences of defects in the damaged layer on the atomic displacement value under irradiation with protons and He2+ ions revealed that the formation of oxygen vacancies under irradiation with He2+ ions is more intense than in the case of irradiation with protons, which in turn results in more pronounced processes of accumulation of radiolysis products in the case of high-dose irradiation.
{"title":"Application of EPR spectroscopy method for comparative analysis of structural damage accumulation kinetics in two-phase lithium-containing ceramics","authors":"Dmitriy I. Shlimas , Daryn B. Borgekov , Artem L. Kozlovskiy","doi":"10.1016/j.omx.2024.100387","DOIUrl":"10.1016/j.omx.2024.100387","url":null,"abstract":"<div><div>The aim of this study is to determine the differences in the damaged layer degradation kinetics in two-phase lithium-containing ceramics based on Li<sub>2</sub>ZrO<sub>3</sub> and Li<sub>4</sub>SiO<sub>4</sub> compounds in the case of irradiation with protons and helium ions, simulating the gas swelling and blistering processes, as well as the accumulation of radiolysis products in the damaged layer. During the conducted studies it was established that in the case of proton irradiation, the dominant role at fluences of 10<sup>15</sup>–10<sup>17</sup> cm<sup>−2</sup> is played by oxygen vacancies, the change in the concentration of which upon reaching critical values causes a decrease in the thermophysical properties, and disordering of the damaged layer. In this case, the accumulation of radiolysis products in the form of HC<sub>2</sub> – and Zr<sup>3+</sup> -defects in the structure of the damaged layer is observed at fluences of 5 × 10<sup>17</sup> cm<sup>−2</sup>, while when irradiated with He<sup>2+</sup> ions, the formation of these types of HC<sub>2</sub> – and Zr<sup>3+</sup> -defects is observed at a fluence of 10<sup>17</sup> cm<sup>−2</sup>. Comparison of the concentration dependences of defects in the damaged layer on the atomic displacement value under irradiation with protons and He<sup>2+</sup> ions revealed that the formation of oxygen vacancies under irradiation with He<sup>2+</sup> ions is more intense than in the case of irradiation with protons, which in turn results in more pronounced processes of accumulation of radiolysis products in the case of high-dose irradiation.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100387"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work the influence of a short-pulsed ion irradiation with a high flux (∼5.5∙1019 cm−2s−1) on structure, optical and photo-electrical properties of gallium oxide thin films have been investigated. The films were produced by the radio-frequency magnetron sputtering method. A part of deposited films was annealed in the air environment (900 °C, 2 h) for synthesis of β-Ga2O3 phase. Obtained films were subjected to the short-pulsed ion irradiation (ion energy - up to 200 keV, pulse duration - 90 ns, current density on the target - up to 15 A/cm2). The influence of the annealing and the irradiation on spectral dependences of absorption, the bandgap width and the Urbach energy have been determined. It was found that irradiation leads to amorphization of crystalline β-Ga2O3 films and a significant change in optical characteristics. In addition, we measured the magnitude of surface dark and photoconductivity of the films. Also, the field and spectral dependences of the photosensitivity of the films were researched. As a result, it was established that short-pulsed irradiation improves the photoelectric properties of amorphous gallium oxide films. The reasons of it are discussed.
{"title":"Influence of short-pulsed Ion irradiation on optical and photoelectrical properties of thin gallium oxide films","authors":"Zhanymgul Koishybayeva , Fedor Konusov , Sergey Pavlov , Dmitrii Sidelev , Artur Nassyrbayev , Dmitry Cheshev , Ruslan Gadyrov , Vladislav Tarbokov , Abdirash Akilbekov","doi":"10.1016/j.omx.2024.100394","DOIUrl":"10.1016/j.omx.2024.100394","url":null,"abstract":"<div><div>In this work the influence of a short-pulsed ion irradiation with a high flux (∼5.5∙10<sup>19</sup> cm<sup>−2</sup>s<sup>−1</sup>) on structure, optical and photo-electrical properties of gallium oxide thin films have been investigated. The films were produced by the radio-frequency magnetron sputtering method. A part of deposited films was annealed in the air environment (900 °C, 2 h) for synthesis of β-Ga<sub>2</sub>O<sub>3</sub> phase. Obtained films were subjected to the short-pulsed ion irradiation (ion energy - up to 200 keV, pulse duration - 90 ns, current density on the target - up to 15 A/cm<sup>2</sup>). The influence of the annealing and the irradiation on spectral dependences of absorption, the bandgap width and the Urbach energy have been determined. It was found that irradiation leads to amorphization of crystalline β-Ga<sub>2</sub>O<sub>3</sub> films and a significant change in optical characteristics. In addition, we measured the magnitude of surface dark and photoconductivity of the films. Also, the field and spectral dependences of the photosensitivity of the films were researched. As a result, it was established that short-pulsed irradiation improves the photoelectric properties of amorphous gallium oxide films. The reasons of it are discussed.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100394"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.omx.2024.100382
G.A. Kaptagay , B.M. Satanova , A.U. Abuova , M. Konuhova , Zh.Ye. Zakiyeva , U. Zh Tolegen , N.O. Koilyk , F.U. Abuova
By means of DFT oxygen evolution reaction on Rh-doped BaTiO3 (001) surface has been modeled. Gibbs free energies for each step of the reaction as well as the values of overpotential have been calculated, taking into account the solvation effect. The position of Rh-induces defect energy levels have been determined. Our findings indicated a substantial reduction in overpotential for the Rhodium-modified TiO2 surface compared to the bare surface. The high overpotential on the bare BaTiO3 surface suggests low OER efficiency, making Rh doping a promising strategy for enhancement.
{"title":"Effect of rhodium doping for photocatalytic activity of barium titanate","authors":"G.A. Kaptagay , B.M. Satanova , A.U. Abuova , M. Konuhova , Zh.Ye. Zakiyeva , U. Zh Tolegen , N.O. Koilyk , F.U. Abuova","doi":"10.1016/j.omx.2024.100382","DOIUrl":"10.1016/j.omx.2024.100382","url":null,"abstract":"<div><div>By means of DFT oxygen evolution reaction on Rh-doped BaTiO<sub>3</sub> (001) surface has been modeled. Gibbs free energies for each step of the reaction as well as the values of overpotential have been calculated, taking into account the solvation effect. The position of Rh-induces defect energy levels have been determined. Our findings indicated a substantial reduction in overpotential for the Rhodium-modified TiO<sub>2</sub> surface compared to the bare surface. The high overpotential on the bare BaTiO<sub>3</sub> surface suggests low OER efficiency, making Rh doping a promising strategy for enhancement.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100382"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.omx.2024.100396
Dmitriy I. Shlimas , Ainagul A. Khametova , Artem L. Kozlovskiy , Maxim V. Zdorovets
The article presents the results of experimental studies of the effect of the stabilizing MgO dopant using the electron spin resonance (ESP) method on enhancement of the stability of Li2ZrO3 ceramics to defect formation processes and accumulation of radiolysis products in the near-surface layer in the case of high-dose irradiation with protons simulating the hydrogenation effects characteristic of processes associated with tritium production. During the conducted studies, it was established that the addition of the stabilizing MgO dopant results in formation of inclusions in the form of the tetragonal MgLi2ZrO4 phase, which leads to an increase in the resistance of the near-surface layers to destructive damage due to the accumulation of structural damage (oxygen vacancies and point defects), as well as products of the physicochemical processes of radiolysis, characteristic of high irradiation fluence values. It was found that in the case of unmodified Li2ZrO3 ceramics, the formation of HC2 – centers is observed at a fluence of 1016 proton/cm2, while for two-phase ceramics, the formation of HC2 – centers is observed at higher fluences, while the intensity of the bands is significantly less than in the case of single-phase unmodified ceramics. The difference in the nature of changes in the intensities of singlet bands responsible for the presence of vacancy defects in the damaged layer, as well as HC2 – centers for single-phase and two-phase ceramics is a direct confirmation of the inhibition of structural degradation mechanisms in two-phase ceramics.
{"title":"Study of defect formation mechanisms in Li2ZrO3/MgLi2ZrO4 ceramics using EPR spectroscopy","authors":"Dmitriy I. Shlimas , Ainagul A. Khametova , Artem L. Kozlovskiy , Maxim V. Zdorovets","doi":"10.1016/j.omx.2024.100396","DOIUrl":"10.1016/j.omx.2024.100396","url":null,"abstract":"<div><div>The article presents the results of experimental studies of the effect of the stabilizing MgO dopant using the electron spin resonance (ESP) method on enhancement of the stability of Li<sub>2</sub>ZrO<sub>3</sub> ceramics to defect formation processes and accumulation of radiolysis products in the near-surface layer in the case of high-dose irradiation with protons simulating the hydrogenation effects characteristic of processes associated with tritium production. During the conducted studies, it was established that the addition of the stabilizing MgO dopant results in formation of inclusions in the form of the tetragonal MgLi<sub>2</sub>ZrO<sub>4</sub> phase, which leads to an increase in the resistance of the near-surface layers to destructive damage due to the accumulation of structural damage (oxygen vacancies and point defects), as well as products of the physicochemical processes of radiolysis, characteristic of high irradiation fluence values. It was found that in the case of unmodified Li<sub>2</sub>ZrO<sub>3</sub> ceramics, the formation of HC<sub>2</sub> – centers is observed at a fluence of 10<sup>16</sup> proton/cm<sup>2</sup>, while for two-phase ceramics, the formation of HC<sub>2</sub> – centers is observed at higher fluences, while the intensity of the bands is significantly less than in the case of single-phase unmodified ceramics. The difference in the nature of changes in the intensities of singlet bands responsible for the presence of vacancy defects in the damaged layer, as well as HC<sub>2</sub> – centers for single-phase and two-phase ceramics is a direct confirmation of the inhibition of structural degradation mechanisms in two-phase ceramics.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100396"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号