Pub Date : 2025-12-26DOI: 10.1016/j.cap.2025.12.019
Eun-Ha Shin , Miyoung Kim
Introducing magnetism into a topological insulator can profoundly alter its electronic structure, leading to exotic phenomena. We present density-functional theory calculations on Gd substitution in the topological insulator Bi2Te3 surface. The surface state and energy gap are investigated as a function of Gd position, concentration, and magnetic ordering. A single Gd prefers to be near the surface, lifting the degeneracy of the topological surface state (TSS) and opening an energy gap. For Gd dimers, intra-quintuple-layer (intra-QL) dimers prefer antiferromagnetic (AFM) ordering due to the superexchange interaction, whereas inter-QL dimers reveal degenerate ferromagnetic and AFM ordering. The AFM intra-atomic-layer dimers retain the Dirac point of TSS, indicating preservation of time reversal symmetry, whereas other Gd dimers open the TSS gap. Our results imply that Gd doping sensitively tunes the electronic structure of topological insulators, depending on its distribution and magnetic coupling, providing a route to manipulate the TSS
{"title":"Structural and magnetic phase stability and the surface states of gd-doped topological insulator Bi2Te3","authors":"Eun-Ha Shin , Miyoung Kim","doi":"10.1016/j.cap.2025.12.019","DOIUrl":"10.1016/j.cap.2025.12.019","url":null,"abstract":"<div><div>Introducing magnetism into a topological insulator can profoundly alter its electronic structure, leading to exotic phenomena. We present density-functional theory calculations on Gd substitution in the topological insulator Bi<sub>2</sub>Te<sub>3</sub> surface. The surface state and energy gap are investigated as a function of Gd position, concentration, and magnetic ordering. A single Gd prefers to be near the surface, lifting the degeneracy of the topological surface state (TSS) and opening an energy gap. For Gd dimers, intra-quintuple-layer (intra-QL) dimers prefer antiferromagnetic (AFM) ordering due to the superexchange interaction, whereas inter-QL dimers reveal degenerate ferromagnetic and AFM ordering. The AFM intra-atomic-layer dimers retain the Dirac point of TSS, indicating preservation of time reversal symmetry, whereas other Gd dimers open the TSS gap. Our results imply that Gd doping sensitively tunes the electronic structure of topological insulators, depending on its distribution and magnetic coupling, providing a route to manipulate the TSS</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"84 ","pages":"Pages 46-52"},"PeriodicalIF":3.1,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-24DOI: 10.1016/j.cap.2025.12.016
Garam Bae , Dohyung Lee , Wooseok Song
Broadband photodetection of two-dimensional (2D) semiconductors is often hampered by their narrow absorption bandwidth and limited sensitivity to short-wavelength photons. In this work, we propose an effective spectral engineering strategy by integrating red-emissive CsPbBrI2 perovskite quantum dots (PQDs) with SnSe layer-based photodetectors. The PQD film functions as a photon down-conversion medium, absorbing ultraviolet (UV) and blue photons and re-emits them at ∼625 nm, near the absorption edge of SnSe. This photon down-conversion significantly enhances the photocurrent response of the hybrid device across the ultraviolet–visible–near-infrared spectrum. Time-resolved photocurrent measurements reveal up to an order-of-magnitude improvement in photoresponse compared to pristine SnSe, particularly under UV excitation. Spectroscopic and morphological analyses confirm the structural integrity and optical activity of the CsPbBrI2 PQD layer, as well as its conformal coverage on the SnSe surface. Furthermore, optimization of PQD coating thickness indicates that a single spin-coating cycle yields the best performance by balancing PL efficiency and photon penetration. The hybrid photodetectors also exhibit stable ON/OFF switching characteristics across all excitation wavelengths. These results establish a versatile and non-invasive approach for extending the spectral sensitivity of 2D semiconductors using photonic down-conversion layers, offering promising opportunities for next-generation broadband optoelectronic devices.
{"title":"Red-emissive perovskite quantum dot-induced monochromatization for broadband photodetection in two-dimensional SnSe","authors":"Garam Bae , Dohyung Lee , Wooseok Song","doi":"10.1016/j.cap.2025.12.016","DOIUrl":"10.1016/j.cap.2025.12.016","url":null,"abstract":"<div><div>Broadband photodetection of two-dimensional (2D) semiconductors is often hampered by their narrow absorption bandwidth and limited sensitivity to short-wavelength photons. In this work, we propose an effective spectral engineering strategy by integrating red-emissive CsPbBrI<sub>2</sub> perovskite quantum dots (PQDs) with SnSe layer-based photodetectors. The PQD film functions as a photon down-conversion medium, absorbing ultraviolet (UV) and blue photons and re-emits them at ∼625 nm, near the absorption edge of SnSe. This photon down-conversion significantly enhances the photocurrent response of the hybrid device across the ultraviolet–visible–near-infrared spectrum. Time-resolved photocurrent measurements reveal up to an order-of-magnitude improvement in photoresponse compared to pristine SnSe, particularly under UV excitation. Spectroscopic and morphological analyses confirm the structural integrity and optical activity of the CsPbBrI<sub>2</sub> PQD layer, as well as its conformal coverage on the SnSe surface. Furthermore, optimization of PQD coating thickness indicates that a single spin-coating cycle yields the best performance by balancing PL efficiency and photon penetration. The hybrid photodetectors also exhibit stable ON/OFF switching characteristics across all excitation wavelengths. These results establish a versatile and non-invasive approach for extending the spectral sensitivity of 2D semiconductors using photonic down-conversion layers, offering promising opportunities for next-generation broadband optoelectronic devices.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"84 ","pages":"Pages 31-37"},"PeriodicalIF":3.1,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-24DOI: 10.1016/j.cap.2025.12.015
Kwangsu Kim , Tae-Eon Park , Sanghoon Kim , Kyoung-Whan Kim
Two-dimensional (2D) materials are a promising class of materials due to their exotic properties, including flexibility, atomically thin layer, and tunability. While Hall measurements are widely used to investigate promising and conductive materials, 2D material devices often exhibit non-uniform current flows due to the difficulty of fabrication, particularly in bottom-contact or via-contact geometries, complicating quantitative analysis. Here, we demonstrate numerical simulation by incorporating non-diagonal terms in the conductivity tensor, enabling accurate estimation of Hall voltages under arbitrary device geometry. The simulation reproduces device resistance and Hall voltage in Hall bar geometry as a function of resistivity tensor, consistent with analytic solutions derived in another study. We estimate Hall voltages in two geometries—bottom-contact and via-contact— and demonstrate how much the device configuration can suppress the Hall voltage depending on the location of probes. This work provides an extendable framework for analyzing transport properties quantitatively in 2D materials and semiconductors.
{"title":"Quantitative analysis of Hall effect in two-dimensional materials","authors":"Kwangsu Kim , Tae-Eon Park , Sanghoon Kim , Kyoung-Whan Kim","doi":"10.1016/j.cap.2025.12.015","DOIUrl":"10.1016/j.cap.2025.12.015","url":null,"abstract":"<div><div>Two-dimensional (2D) materials are a promising class of materials due to their exotic properties, including flexibility, atomically thin layer, and tunability. While Hall measurements are widely used to investigate promising and conductive materials, 2D material devices often exhibit non-uniform current flows due to the difficulty of fabrication, particularly in bottom-contact or via-contact geometries, complicating quantitative analysis. Here, we demonstrate numerical simulation by incorporating non-diagonal terms in the conductivity tensor, enabling accurate estimation of Hall voltages under arbitrary device geometry. The simulation reproduces device resistance and Hall voltage in Hall bar geometry as a function of resistivity tensor, consistent with analytic solutions derived in another study. We estimate Hall voltages in two geometries—bottom-contact and via-contact— and demonstrate how much the device configuration can suppress the Hall voltage depending on the location of probes. This work provides an extendable framework for analyzing transport properties quantitatively in 2D materials and semiconductors.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"84 ","pages":"Pages 38-45"},"PeriodicalIF":3.1,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-23DOI: 10.1016/j.cap.2025.12.014
Dahee Jin , Jeongmin Koo , Yonghwan Kim , Woojoo Lee , Il Hwan Cho
Photodetectors (PDs) with high thermal stability are crucial for applications in extreme environments. This study analyzes the temperature-dependent characteristics of a Feedback Field-Effect Transistor (FBFET)-based photodetector within a temperature range of 300 K–450 K using TCAD simulations. The results show that the proposed PD maintains a low dark current and stable illumination current, ensuring excellent thermal stability. While responsivity increases due to thermally assisted tunneling, sensitivity declines with rising temperature. Structural optimizations, such as adjusting the light incident region and body thickness, further enhance performance. These findings provide valuable insights for the development of next-generation high-temperature PDs.
具有高热稳定性的光电探测器（pd）对于极端环境中的应用至关重要。本研究利用TCAD模拟分析了300 K - 450 K温度范围内基于反馈场效应晶体管（FBFET）的光电探测器的温度依赖特性。结果表明，该器件具有较低的暗电流和稳定的照明电流，具有良好的热稳定性。虽然响应度由于热辅助隧道而增加，但灵敏度随着温度的升高而下降。结构优化，如调整光入射区域和机身厚度，进一步提高了性能。这些发现为下一代高温pd的开发提供了有价值的见解。
{"title":"Analysis of temperature dependent characteristics of photodetector based on feedback field effect transistor","authors":"Dahee Jin , Jeongmin Koo , Yonghwan Kim , Woojoo Lee , Il Hwan Cho","doi":"10.1016/j.cap.2025.12.014","DOIUrl":"10.1016/j.cap.2025.12.014","url":null,"abstract":"<div><div>Photodetectors (PDs) with high thermal stability are crucial for applications in extreme environments. This study analyzes the temperature-dependent characteristics of a Feedback Field-Effect Transistor (FBFET)-based photodetector within a temperature range of 300 K–450 K using TCAD simulations. The results show that the proposed PD maintains a low dark current and stable illumination current, ensuring excellent thermal stability. While responsivity increases due to thermally assisted tunneling, sensitivity declines with rising temperature. Structural optimizations, such as adjusting the light incident region and body thickness, further enhance performance. These findings provide valuable insights for the development of next-generation high-temperature PDs.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"84 ","pages":"Pages 68-74"},"PeriodicalIF":3.1,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surface-Enhanced Raman Scattering (SERS) is a powerful technique for ultrasensitive molecular detection; however, achieving both high sensitivity and reproducibility remains difficult with conventional plasmonic substrates. This work presents a novel plasmonic dual-silver–decorated dielectric nanoantenna array designed to overcome these limitations. Dielectric nanoantennas were first lithographically fabricated, followed by deposition of a thin silver base layer and a second layer of silver nanoparticles. This dual-silver architecture enables multiscale plasmonic coupling and generates dense electromagnetic hotspots, significantly enhancing local field intensities. Structural and optical analyses using SEM and UV–Vis spectroscopy confirmed uniform silver distribution and strong plasmonic activity. Using Rhodamine 6G as a probe, Raman measurements demonstrated excellent signal uniformity and enhancement factors exceeding 107. Finite-Difference Time-Domain simulations further verified strong near-field enhancement at the metal–dielectric interface. Owing to its high sensitivity, stability, and reproducibility, the proposed hybrid nanoantenna substrate is well suited for chemical, environmental, and biological sensing applications.
{"title":"Plasmonic dual-silver decorated dielectric nanoantenna arrays for enhanced surface-enhanced Raman scattering (SERS) sensors","authors":"Ravindra Pratap Singh , N. Nagabhooshanam , Yogendra Thakur , Deepak Nathiya , M.D Anto Praveena , U.L. Nagendra Kumar , A. Rajaram","doi":"10.1016/j.cap.2025.12.013","DOIUrl":"10.1016/j.cap.2025.12.013","url":null,"abstract":"<div><div>Surface-Enhanced Raman Scattering (SERS) is a powerful technique for ultrasensitive molecular detection; however, achieving both high sensitivity and reproducibility remains difficult with conventional plasmonic substrates. This work presents a novel plasmonic dual-silver–decorated dielectric nanoantenna array designed to overcome these limitations. Dielectric nanoantennas were first lithographically fabricated, followed by deposition of a thin silver base layer and a second layer of silver nanoparticles. This dual-silver architecture enables multiscale plasmonic coupling and generates dense electromagnetic hotspots, significantly enhancing local field intensities. Structural and optical analyses using SEM and UV–Vis spectroscopy confirmed uniform silver distribution and strong plasmonic activity. Using Rhodamine 6G as a probe, Raman measurements demonstrated excellent signal uniformity and enhancement factors exceeding 10<sup>7</sup>. Finite-Difference Time-Domain simulations further verified strong near-field enhancement at the metal–dielectric interface. Owing to its high sensitivity, stability, and reproducibility, the proposed hybrid nanoantenna substrate is well suited for chemical, environmental, and biological sensing applications.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"84 ","pages":"Pages 136-144"},"PeriodicalIF":3.1,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-22DOI: 10.1016/j.cap.2025.12.012
Rosenti Pasaribu , Andreas Setiawan , Rini Widyaningrum , Mitrayana
Visual assessment of burn wounds is subjective and often fails to detect hemoglobin-weighted vascular changes that mark phase transitions. We evaluated photoacoustic imaging (PAI) using relative hemoglobin (Hbrel), an internally normalized wound-to-healthy tissue comparison, to detect these transitions. Moist-thermal burns were induced ex vivo on Sprague-Dawley rat skin and imaged on days 1, 7, and 14 using a custom frequency-domain PAI system with an 808-nm diode laser and condenser microphone. Raster scanning with Fourier-transform-based signal extraction provided optimal contrast at a 15 kHz modulation frequency and a 50 % duty cycle. Hbrel values reached 162 % ± 10 % on day 1, declined to 142 % ± 10 % on day 7, and 111 % ± 2 % on day 14, reflecting reduced vasodilation and progressive healing. These findings demonstrate that PAI can differentiate healthy tissue from burn regions, highlighting its potential as an adjunct tool for monitoring burn wound recovery.
{"title":"Advancing burn wound monitoring: A non-invasive photoacoustic imaging approach","authors":"Rosenti Pasaribu , Andreas Setiawan , Rini Widyaningrum , Mitrayana","doi":"10.1016/j.cap.2025.12.012","DOIUrl":"10.1016/j.cap.2025.12.012","url":null,"abstract":"<div><div>Visual assessment of burn wounds is subjective and often fails to detect hemoglobin-weighted vascular changes that mark phase transitions. We evaluated photoacoustic imaging (PAI) using relative hemoglobin (Hb<sub>rel</sub>), an internally normalized wound-to-healthy tissue comparison, to detect these transitions. Moist-thermal burns were induced ex vivo on Sprague-Dawley rat skin and imaged on days 1, 7, and 14 using a custom frequency-domain PAI system with an 808-nm diode laser and condenser microphone. Raster scanning with Fourier-transform-based signal extraction provided optimal contrast at a 15 kHz modulation frequency and a 50 % duty cycle. Hb<sub>rel</sub> values reached 162 % ± 10 % on day 1, declined to 142 % ± 10 % on day 7, and 111 % ± 2 % on day 14, reflecting reduced vasodilation and progressive healing. These findings demonstrate that PAI can differentiate healthy tissue from burn regions, highlighting its potential as an adjunct tool for monitoring burn wound recovery.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"84 ","pages":"Pages 53-61"},"PeriodicalIF":3.1,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.cap.2025.12.009
Won Uk Jeong , Jung Bin Ahn , Tae Jin Jeong , Yeonhee Ryu , Sung Kim
We report a systematic study of excitonic resonance and valley polarization in monolayer Mo1-xWxS2 alloys with compositions x = 0, 0.4, 0.6, and 1.0. Monolayers prepared by mechanical exfoliation were characterized by microscopy, Raman, and X-ray photoelectron spectroscopy. Unpolarized photoluminescence (PL) spectra show a progressive blueshift of the A-exciton peak with increasing W content, consistent with bandgap evolution. Circularly polarized PL measurements reveal valley-selective emission, with the degree of valley polarization (DVP) defined as DVP = (Ico − Icross)/(Ico + Icross). The DVP exhibits a maximum near the A-exciton resonance and increases from 3.0 % at x = 0–20.4 % at x = 1.0, accompanied by a blueshift in peak position. The enhancement is attributed to stronger spin–orbit coupling, reduced exciton–phonon scattering, and alloy-modulated relaxation. These findings demonstrate alloy composition as a practical tuning parameter for valley polarization in 2D semiconductors, offering guidance for valleytronic and chiroptical devices.
{"title":"Composition-tunable valley polarization in monolayer Mo1-xWxS2 alloys","authors":"Won Uk Jeong , Jung Bin Ahn , Tae Jin Jeong , Yeonhee Ryu , Sung Kim","doi":"10.1016/j.cap.2025.12.009","DOIUrl":"10.1016/j.cap.2025.12.009","url":null,"abstract":"<div><div>We report a systematic study of excitonic resonance and valley polarization in monolayer Mo<sub>1-x</sub>W<sub>x</sub>S<sub>2</sub> alloys with compositions x = 0, 0.4, 0.6, and 1.0. Monolayers prepared by mechanical exfoliation were characterized by microscopy, Raman, and X-ray photoelectron spectroscopy. Unpolarized photoluminescence (PL) spectra show a progressive blueshift of the A-exciton peak with increasing W content, consistent with bandgap evolution. Circularly polarized PL measurements reveal valley-selective emission, with the degree of valley polarization (DVP) defined as DVP = (I<sub>co</sub> − I<sub>cross</sub>)/(I<sub>co</sub> + I<sub>cross</sub>). The DVP exhibits a maximum near the A-exciton resonance and increases from 3.0 % at x = 0–20.4 % at x = 1.0, accompanied by a blueshift in peak position. The enhancement is attributed to stronger spin–orbit coupling, reduced exciton–phonon scattering, and alloy-modulated relaxation. These findings demonstrate alloy composition as a practical tuning parameter for valley polarization in 2D semiconductors, offering guidance for valleytronic and chiroptical devices.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"84 ","pages":"Pages 12-18"},"PeriodicalIF":3.1,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.cap.2025.11.015
Eun-Suk Jeong, Sang-Wook Han
Extended X-ray absorption fine structure (EXAFS) is a unique tool used to describe local structural properties around a selected element in a material. However, the quantitative analysis of EXAFS data remains a non-trivial task, especially for beginners in the field of EXAFS. While AI techniques can assist in the analysis of EXAFS data, there are still numerous challenges to overcome for the complete automation of EXAFS data analysis. We explored the automatic analysis of EXAFS data from various materials using deep reinforcement learning (DRL) methods. Unlike other AI techniques, DRL methods do not necessitate a large amount of pre-prepared data to train the neural networks (NNs) of an AI system, as they achieve optimal fits of EXAFS data by using a reward value set as the reciprocal of the R-factor of an EXAFS data fit. Our results strongly indicate that the DRL-EXAFS method can quantitatively analyze EXAFS data.
{"title":"Can artificial intelligence techniques replace human labor in EXAFS data analysis?","authors":"Eun-Suk Jeong, Sang-Wook Han","doi":"10.1016/j.cap.2025.11.015","DOIUrl":"10.1016/j.cap.2025.11.015","url":null,"abstract":"<div><div>Extended X-ray absorption fine structure (EXAFS) is a unique tool used to describe local structural properties around a selected element in a material. However, the quantitative analysis of EXAFS data remains a non-trivial task, especially for beginners in the field of EXAFS. While AI techniques can assist in the analysis of EXAFS data, there are still numerous challenges to overcome for the complete automation of EXAFS data analysis. We explored the automatic analysis of EXAFS data from various materials using deep reinforcement learning (DRL) methods. Unlike other AI techniques, DRL methods do not necessitate a large amount of pre-prepared data to train the neural networks (NNs) of an AI system, as they achieve optimal fits of EXAFS data by using a reward value set as the reciprocal of the <em>R</em>-factor of an EXAFS data fit. Our results strongly indicate that the DRL-EXAFS method can quantitatively analyze EXAFS data.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"84 ","pages":"Pages 1-11"},"PeriodicalIF":3.1,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145801950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.cap.2025.12.010
Sincy Anna Oommen, Arya Gopinath, Parvathy O. Nair, P.R. Biju
A series of Li(1-x)ZnNbO4:xEu3+ phosphors were successfully synthesized using the solid state reaction method. XRD results confirmed the formation of a tetragonal structure with a space group of P4122. The DRS and PL excitation spectra confirmed that the prepared phosphors can be efficiently excited by UV and nUV light sources. Under 270 nm excitation, the host exhibited a broad blue emission band, while LiZnNbO4:xEu3+ phosphors exhibit both blue and characteristic emission bands of Eu3+ ions resulting a tunable white light emission. Under 393 nm excitation, the prepared phosphors exhibit orange-red emission. Concentration quenching was observed at x = 0.06, and the critical distance calculated to be 17.12 Å. The energy transfer mechanism was determined to be dipole-dipole interaction. The prepared phosphors exhibit excellent color tunability from blue to red and in near white light emission, confirming their promise for potential use in advanced photonic applications.
{"title":"Tunable dual emission in host sensitized Eu3+ doped LiZnNbO4 phosphor for white light applications","authors":"Sincy Anna Oommen, Arya Gopinath, Parvathy O. Nair, P.R. Biju","doi":"10.1016/j.cap.2025.12.010","DOIUrl":"10.1016/j.cap.2025.12.010","url":null,"abstract":"<div><div>A series of Li<sub>(1-x)</sub>ZnNbO<sub>4</sub>:xEu<sup>3+</sup> phosphors were successfully synthesized using the solid state reaction method. XRD results confirmed the formation of a tetragonal structure with a space group of <em>P</em>4<sub>1</sub>22. The DRS and PL excitation spectra confirmed that the prepared phosphors can be efficiently excited by UV and nUV light sources. Under 270 nm excitation, the host exhibited a broad blue emission band, while LiZnNbO<sub>4</sub>:xEu<sup>3+</sup> phosphors exhibit both blue and characteristic emission bands of Eu<sup>3+</sup> ions resulting a tunable white light emission. Under 393 nm excitation, the prepared phosphors exhibit orange-red emission. Concentration quenching was observed at x = 0.06, and the critical distance calculated to be 17.12 Å. The energy transfer mechanism was determined to be dipole-dipole interaction. The prepared phosphors exhibit excellent color tunability from blue to red and in near white light emission, confirming their promise for potential use in advanced photonic applications.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"84 ","pages":"Pages 19-30"},"PeriodicalIF":3.1,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-15DOI: 10.1016/j.cap.2025.12.008
Soo-Hyuk Kang, Jong-Hwan Lee, Goo-Hwan Jeong
Research on gas-detection sensors using metal oxides has gained significant attention due to their potential applications in environmental monitoring and safety. ZnO tetrapods, owing to their distinctive morphology, offer enhanced gas sensing properties. In this study, ZnO tetrapods were synthesized using an atmospheric pressure microwave plasma (APMP) system with 10 μm Zn powder as a precursor. This method enables rapid, large-scale production without the need for high-vacuum or high-temperature environments. The synthesized ZnO tetrapods exhibited particle sizes ranging from 100 to 700 nm, depending on applied plasma power and collection location. The ZnO tetrapods were subsequently spray-coated onto SiO2/Si substrates with Au electrodes to fabricate gas sensors. The NH3 sensing performance was evaluated, revealing that reducing the particle size from 700 to 100 nm increased the sensor response, defined as Ra/Rg (where Ra and Rg represent the electrical resistance in dry air and NH3 gas, respectively), by approximately 24.4 %, from 1.09 to 1.31. These results demonstrate that ZnO tetrapods with controlled morphology can serve as highly efficient gas-sensing materials.
{"title":"Size-controlled synthesis of ZnO tetrapods using atmospheric pressure microwave plasma jets and application in NH3 gas detection","authors":"Soo-Hyuk Kang, Jong-Hwan Lee, Goo-Hwan Jeong","doi":"10.1016/j.cap.2025.12.008","DOIUrl":"10.1016/j.cap.2025.12.008","url":null,"abstract":"<div><div>Research on gas-detection sensors using metal oxides has gained significant attention due to their potential applications in environmental monitoring and safety. ZnO tetrapods, owing to their distinctive morphology, offer enhanced gas sensing properties. In this study, ZnO tetrapods were synthesized using an atmospheric pressure microwave plasma (APMP) system with 10 μm Zn powder as a precursor. This method enables rapid, large-scale production without the need for high-vacuum or high-temperature environments. The synthesized ZnO tetrapods exhibited particle sizes ranging from 100 to 700 nm, depending on applied plasma power and collection location. The ZnO tetrapods were subsequently spray-coated onto SiO<sub>2</sub>/Si substrates with Au electrodes to fabricate gas sensors. The NH<sub>3</sub> sensing performance was evaluated, revealing that reducing the particle size from 700 to 100 nm increased the sensor response, defined as <em>R</em><sub><em>a</em></sub>/<em>R</em><sub><em>g</em></sub> (where <em>R</em><sub><em>a</em></sub> and <em>R</em><sub><em>g</em></sub> represent the electrical resistance in dry air and NH<sub>3</sub> gas, respectively), by approximately 24.4 %, from 1.09 to 1.31. These results demonstrate that ZnO tetrapods with controlled morphology can serve as highly efficient gas-sensing materials.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"83 ","pages":"Pages 140-149"},"PeriodicalIF":3.1,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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