Pub Date : 2025-03-11DOI: 10.1016/j.physb.2025.417138
Diana Pradhan , Anurag Gartia , Kiran K. Sahoo , Surya P. Ghosh , Tanmoy Parida , Raghvendra S. Saxena , Jyoti P. Kar
The tunable material characteristics of molybdenum disulfide (MoS2) for next-generation of IR detectors have gained a lot of attention in recent years. Post-deposition morphological and microstructural characterizations of MoS2 films were carried out by FESEM, AFM, XRD and Raman techniques. A homogeneous distribution of grains was observed from the FESEM micrographs. In this work, the photoresponse of MoS2 based junctions has been studied elaborately using the current-voltage and current-time measurements. The near IR response was evaluated from the current On/Off ratio, rise time, fall time, responsivity and specific detectivity of the detectors upon illumination of IR source of wavelength 850 nm, 940 nm, and 1060 nm. MoS2 based resistive conductor, n-MoS2/p-Si intrinsic heterojunction, n-MoS2/p-MoS2 homojunction, and Pt/MoS2 Schottky junction structures were fabricated to study the IR response. Pt/MoS2 Schottky junction has shown the highest current On/Off ratio, responsivity, and specific detectivity, whereas MoS2 based photoconductors have exhibited fastest IR response.
{"title":"Feasibility study of MoS2 based junctions for infrared detection","authors":"Diana Pradhan , Anurag Gartia , Kiran K. Sahoo , Surya P. Ghosh , Tanmoy Parida , Raghvendra S. Saxena , Jyoti P. Kar","doi":"10.1016/j.physb.2025.417138","DOIUrl":"10.1016/j.physb.2025.417138","url":null,"abstract":"<div><div>The tunable material characteristics of molybdenum disulfide (MoS<sub>2</sub>) for next-generation of IR detectors have gained a lot of attention in recent years. Post-deposition morphological and microstructural characterizations of MoS<sub>2</sub> films were carried out by FESEM, AFM, XRD and Raman techniques. A homogeneous distribution of grains was observed from the FESEM micrographs. In this work, the photoresponse of MoS<sub>2</sub> based junctions has been studied elaborately using the current-voltage and current-time measurements. The near IR response was evaluated from the current On/Off ratio, rise time, fall time, responsivity and specific detectivity of the detectors upon illumination of IR source of wavelength 850 nm, 940 nm, and 1060 nm. MoS<sub>2</sub> based resistive conductor, n-MoS<sub>2</sub>/p-Si intrinsic heterojunction, n-MoS<sub>2</sub>/p-MoS<sub>2</sub> homojunction, and Pt/MoS<sub>2</sub> Schottky junction structures were fabricated to study the IR response. Pt/MoS<sub>2</sub> Schottky junction has shown the highest current On/Off ratio, responsivity, and specific detectivity, whereas MoS<sub>2</sub> based photoconductors have exhibited fastest IR response.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"706 ","pages":"Article 417138"},"PeriodicalIF":2.8,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-03-11DOI: 10.1016/j.physb.2025.417133
Dalila Khlaifia , Mansour Aouassa , Lorenzo Torrisi , Mariapompea Cutroneo , A.K. Aladim , Isabelle Berbezier
This study presents a hybrid metal-insulator-semiconductor (MIS) photodetector integrating silicon quantum dots (Si QDs) with a multilayer reduced graphene oxide (rGO) film. A 1 nm amorphous silicon-on-insulator (SOI) film, deposited by molecular beam epitaxy (MBE), undergoes solid-state dewetting to form single-crystal Si QDs (∼6 nm) encapsulated in SiO2. A multilayer graphene film is then deposited via spray coating, oxidized, and chemically reduced to obtain rGO, as confirmed by Raman analysis. The hybrid MIS structure, with transparent AuPd contacts, is characterized by capacitance-voltage (C-V) and current-voltage (I-V) measurements. The rGO enhances optoelectronic performance by improving charge collection and interaction with Si QDs. Experimental results demonstrate ultra-low dark current and a photocurrent amplified up to 100 times under low bias, highlighting the synergy between Si QDs' optical properties and rGO's efficient charge transport and open new pathways for the development of high-sensitivity, low-power optoelectronic devices.
{"title":"RGO-Si QDs hybrid photodetector with enhanced photosensitivity","authors":"Dalila Khlaifia , Mansour Aouassa , Lorenzo Torrisi , Mariapompea Cutroneo , A.K. Aladim , Isabelle Berbezier","doi":"10.1016/j.physb.2025.417133","DOIUrl":"10.1016/j.physb.2025.417133","url":null,"abstract":"<div><div>This study presents a hybrid metal-insulator-semiconductor (MIS) photodetector integrating silicon quantum dots (Si QDs) with a multilayer reduced graphene oxide (rGO) film. A 1 nm amorphous silicon-on-insulator (SOI) film, deposited by molecular beam epitaxy (MBE), undergoes solid-state dewetting to form single-crystal Si QDs (∼6 nm) encapsulated in SiO<sub>2</sub>. A multilayer graphene film is then deposited via spray coating, oxidized, and chemically reduced to obtain rGO, as confirmed by Raman analysis. The hybrid MIS structure, with transparent AuPd contacts, is characterized by capacitance-voltage (C-V) and current-voltage (I-V) measurements. The rGO enhances optoelectronic performance by improving charge collection and interaction with Si QDs. Experimental results demonstrate ultra-low dark current and a photocurrent amplified up to 100 times under low bias, highlighting the synergy between Si QDs' optical properties and rGO's efficient charge transport and open new pathways for the development of high-sensitivity, low-power optoelectronic devices.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"706 ","pages":"Article 417133"},"PeriodicalIF":2.8,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Ab-initio characterization of NaGeX (X =Br, F, I) compounds has examined their structural, thermodynamical, optoelectronic, and thermoelectric characteristics. Spin polarized first principles calculations validate these compounds non-magnetic, direct band gap electronic properties. The material’s optoelectronic characteristics change when exposed to light. Controlling the material’s visible and ultraviolet optical absorption shows its disordered character. The compounds NaGeX (X =Br, F, I) have stable thermodynamic properties with temperature variations. As temperature increases, NaGeF shows significant patterns. Thermoelectric qualities include thermal and electrical conductivity, Seebeck coefficient, figure of merit (), and power factor. The study takes chemical potential ( eV) and temperature T(K) as variables. At normal ambient temperature, NaGeBr, NaGeF, and NaGeI have outstanding values of 0.83, 0.95, and 0.82. Interestingly, the NaGeF compound maintains high values from 0.95 to 0.85 across the temperature range. NaGeF exceeds the other two materials in renewable energy applications.
{"title":"Theoretical analysis of Ge-based perovskite halides for renewable energy applications","authors":"Muhammad Zulfiqar , Arslan Zulfiqar , Shafaat Hussain Mirza , Ijaz Hussain , Nargis Bano","doi":"10.1016/j.physb.2025.417108","DOIUrl":"10.1016/j.physb.2025.417108","url":null,"abstract":"<div><div>Ab-initio characterization of NaGeX<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> (X =Br, F, I) compounds has examined their structural, thermodynamical, optoelectronic, and thermoelectric characteristics. Spin polarized first principles calculations validate these compounds non-magnetic, direct band gap electronic properties. The material’s optoelectronic characteristics change when exposed to light. Controlling the material’s visible and ultraviolet optical absorption shows its disordered character. The compounds NaGeX<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> (X =Br, F, I) have stable thermodynamic properties with temperature variations. As temperature increases, NaGeF<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> shows significant patterns. Thermoelectric qualities include thermal and electrical conductivity, Seebeck coefficient, figure of merit (<span><math><mrow><mi>z</mi><mi>T</mi></mrow></math></span>), and power factor. The study takes chemical potential <span><math><mi>μ</mi></math></span>( eV) and temperature T(K) as variables. At normal ambient temperature, NaGeBr<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>, NaGeF<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>, and NaGeI<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> have outstanding <span><math><mrow><mi>z</mi><mi>T</mi></mrow></math></span> values of 0.83, 0.95, and 0.82. Interestingly, the NaGeF<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> compound maintains high <span><math><mrow><mi>z</mi><mi>T</mi></mrow></math></span> values from 0.95 to 0.85 across the temperature range. NaGeF<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> exceeds the other two materials in renewable energy applications.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"706 ","pages":"Article 417108"},"PeriodicalIF":2.8,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-03-10DOI: 10.1016/j.physb.2025.417131
Abdullah Karaca , Dilber Esra Yıldız , Ali Akbar Hussaini , Fatma Unal , Murat Yıldırım
This study presents the synthesis and characterization of Tm-doped ZnO particles deposited on n-Si and p-Si substrates using the spin coating technique, resulting in the fabrication of Al/Tm:ZnO/n-Si and Al/Tm:ZnO/p-Si photodetectors. The electrical performance of these photodetectors was systematically assessed through current-voltage (I-V) and current-time (I-t) measurements, conducted across a spectrum of light power intensities and wavelengths. Essential parameters, including the ideality factor, series resistance, and barrier height, were determined to evaluate the operational characteristics of the devices. Comparative analysis unveiled distinct behaviors in sensitivity and detection capability between the two configurations. The Al/Tm:ZnO/n-Si photodetector showed a consistent decline in detection ability as the light power intensity increased, suggesting a significant influence of recombination processes and interlayer defects. In contrast, the Al/Tm:ZnO/p-Si photodetector displayed more intricate variations in detection capability, indicating beneficial interactions at the interface that may mitigate some of the detrimental effects typically associated with elevated light intensity. Furthermore, the Al/Tm:ZnO/p-Si photodetector structure's ability to sustain high responsivity under varying illumination conditions and across a broad wavelength range highlights its promising potential for applications in photonic devices.
{"title":"Optoelectrical characterization of a UV–Vis–NIR broadband photodetector based on Tm-doped ZnO","authors":"Abdullah Karaca , Dilber Esra Yıldız , Ali Akbar Hussaini , Fatma Unal , Murat Yıldırım","doi":"10.1016/j.physb.2025.417131","DOIUrl":"10.1016/j.physb.2025.417131","url":null,"abstract":"<div><div>This study presents the synthesis and characterization of Tm-doped ZnO particles deposited on n-Si and p-Si substrates using the spin coating technique, resulting in the fabrication of Al/Tm:ZnO/n-Si and Al/Tm:ZnO/p-Si photodetectors. The electrical performance of these photodetectors was systematically assessed through current-voltage (I-V) and current-time (I-t) measurements, conducted across a spectrum of light power intensities and wavelengths. Essential parameters, including the ideality factor, series resistance, and barrier height, were determined to evaluate the operational characteristics of the devices. Comparative analysis unveiled distinct behaviors in sensitivity and detection capability between the two configurations. The Al/Tm:ZnO/n-Si photodetector showed a consistent decline in detection ability as the light power intensity increased, suggesting a significant influence of recombination processes and interlayer defects. In contrast, the Al/Tm:ZnO/p-Si photodetector displayed more intricate variations in detection capability, indicating beneficial interactions at the interface that may mitigate some of the detrimental effects typically associated with elevated light intensity. Furthermore, the Al/Tm:ZnO/p-Si photodetector structure's ability to sustain high responsivity under varying illumination conditions and across a broad wavelength range highlights its promising potential for applications in photonic devices.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"706 ","pages":"Article 417131"},"PeriodicalIF":2.8,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-03-08DOI: 10.1016/j.physb.2025.417128
Jirarut Joonhuay , Paphavee van Dommelen , Wen-Jen Lee
Metal-semiconductor hybrid structures have gained attention over the decades for enhancing semiconductor optical performances through the excellent absorption properties of plasmonic metals. In this study, we investigated plasmonic enhancement in GaAs/Al0.36Ga0.64As tunnel-coupled quantum wells with Au layers of two thicknesses and a titanium dioxide spacer layer. Our investigation was based on an analysis of temperature- and excitation-dependent photoluminescence (PL) intensity. A thicker Au layer was found to increase PL intensity. Electron temperature and scattering energy rate analyses explained this behavior as the result of plasmonic effects-driven amplified excitation power. Notably, this hybrid structure demonstrated high PL intensity even at low excitation densities. Therefore, this work advances the understanding of plasmonic effects in semiconductor structures and reveals a pathway to high PL intensity at low excitation densities for more efficient near-infrared optoelectronic devices.
{"title":"The improvement of optical properties of tunnel coupled quantum wells of GaAs/AlGaAs by surface plasmonic effects","authors":"Jirarut Joonhuay , Paphavee van Dommelen , Wen-Jen Lee","doi":"10.1016/j.physb.2025.417128","DOIUrl":"10.1016/j.physb.2025.417128","url":null,"abstract":"<div><div>Metal-semiconductor hybrid structures have gained attention over the decades for enhancing semiconductor optical performances through the excellent absorption properties of plasmonic metals. In this study, we investigated plasmonic enhancement in GaAs/Al<sub>0.36</sub>Ga<sub>0.64</sub>As tunnel-coupled quantum wells with Au layers of two thicknesses and a titanium dioxide spacer layer. Our investigation was based on an analysis of temperature- and excitation-dependent photoluminescence (PL) intensity. A thicker Au layer was found to increase PL intensity. Electron temperature and scattering energy rate analyses explained this behavior as the result of plasmonic effects-driven amplified excitation power. Notably, this hybrid structure demonstrated high PL intensity even at low excitation densities. Therefore, this work advances the understanding of plasmonic effects in semiconductor structures and reveals a pathway to high PL intensity at low excitation densities for more efficient near-infrared optoelectronic devices.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"706 ","pages":"Article 417128"},"PeriodicalIF":2.8,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
We studied low-temperature specific heat capacity of 3D lead nanowires formed in porous glass with characteristic conductive network size d = 7 nm. The absolute value of the specific heat capacity increased in nanostructured lead compared to the bulk material, however its functional dependence on temperature remained virtually unchanged. The Debye temperature of nanostructured lead θD = 85 ± 2 K decreased compared to bulk lead value θDbulk ≈ 87 К - 105 K, likely due to the softening of the phonon spectrum in nanostructured lead. The Sommerfeld constant also decreased in nanostructured lead γ = 7 ± 3 μJ g−1 K−2 compared to bulk lead γbulk = 15.1 μJ g−1 K−2, which is likely due to a change in the density of electronic states on the Fermi surface in the nanostructure. A jump in the temperature dependence of the heat capacity of nanostructured lead corresponding to the transition of lead nanofilaments to the superconducting state was recorded at a temperature Tc close to Tcbulk for bulk lead. The amplitude of the superconducting transition jumps in the specific heat capacity of nanostructured lead decreased with increasing magnetic field. The temperature dependences of the specific heat capacity of electrons in the superconducting state for nanostructured lead are consistent with the Eliashberg theory for superconductors with strong coupling.
{"title":"Low-temperature heat capacity of nanostructured lead in porous glass","authors":"A.E. Shitov , N.Yu. Mikhailin , Yu.A. Kumzerov , D.V. Shamshur","doi":"10.1016/j.physb.2025.417118","DOIUrl":"10.1016/j.physb.2025.417118","url":null,"abstract":"<div><div>We studied low-temperature specific heat capacity of 3D lead nanowires formed in porous glass with characteristic conductive network size <em>d</em> = 7 nm. The absolute value of the specific heat capacity increased in nanostructured lead compared to the bulk material, however its functional dependence on temperature remained virtually unchanged. The Debye temperature of nanostructured lead <em>θ</em><sub><em>D</em></sub> = 85 ± 2 K decreased compared to bulk lead value <em>θ</em><sub><em>D</em></sub><sup><em>bulk</em></sup> ≈ 87 К - 105 K, likely due to the softening of the phonon spectrum in nanostructured lead. The Sommerfeld constant also decreased in nanostructured lead <em>γ</em> = 7 ± 3 μJ g<sup>−1</sup> K<sup>−2</sup> compared to bulk lead <em>γ</em><sup><em>bulk</em></sup> = 15.1 μJ g<sup>−1</sup> K<sup>−2</sup>, which is likely due to a change in the density of electronic states on the Fermi surface in the nanostructure. A jump in the temperature dependence of the heat capacity of nanostructured lead corresponding to the transition of lead nanofilaments to the superconducting state was recorded at a temperature <em>T</em><sub><em>c</em></sub> close to <em>T</em><sub><em>c</em></sub><sup><em>bulk</em></sup> for bulk lead. The amplitude of the superconducting transition jumps in the specific heat capacity of nanostructured lead decreased with increasing magnetic field. The temperature dependences of the specific heat capacity of electrons in the superconducting state for nanostructured lead are consistent with the Eliashberg theory for superconductors with strong coupling.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"706 ","pages":"Article 417118"},"PeriodicalIF":2.8,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-03-08DOI: 10.1016/j.physb.2025.417130
Betzabel N. Silva-Carrera , Nilo F. Cano , Felix V.S. Cruz , Edwin J. Pilco , T.K. Gundu Rao , J.F. Benavente , José F.D. Chubaci
The combined effect of heat treatment and irradiation on the thermoluminescent response of natural blue quartz was studied. Samples were subjected to different heat treatment temperatures, pre-dose doses, and thermal activation temperatures to sensitize the Thermoluminescence (TL) response of blue quartz. Blue quartz pellets produced by sintering at 1200 °C were sensitized with a combination of different pre-doses and thermal activation temperatures. It was found that the maximum TL intensity occurred for a pre-dose of 500 Gy and a thermal activation temperature of 550 °C, resulting in a dosimetric peak with a TL signal 150 times more intense than the initial one. The kinetic parameters of the TL glow curve of the sensitized pellets were analyzed by the methods of different heating rates, Tm-Tstop, and deconvolution. The dosimetric properties of the sensitized blue quartz pellets were also evaluated using the 220 °C TL peak.
{"title":"Effect of heat treatment and gamma irradiation on TL emission sensitivity of blue quartz crystal","authors":"Betzabel N. Silva-Carrera , Nilo F. Cano , Felix V.S. Cruz , Edwin J. Pilco , T.K. Gundu Rao , J.F. Benavente , José F.D. Chubaci","doi":"10.1016/j.physb.2025.417130","DOIUrl":"10.1016/j.physb.2025.417130","url":null,"abstract":"<div><div>The combined effect of heat treatment and irradiation on the thermoluminescent response of natural blue quartz was studied. Samples were subjected to different heat treatment temperatures, pre-dose doses, and thermal activation temperatures to sensitize the Thermoluminescence (TL) response of blue quartz. Blue quartz pellets produced by sintering at 1200 °C were sensitized with a combination of different pre-doses and thermal activation temperatures. It was found that the maximum TL intensity occurred for a pre-dose of 500 Gy and a thermal activation temperature of 550 °C, resulting in a dosimetric peak with a TL signal 150 times more intense than the initial one. The kinetic parameters of the TL glow curve of the sensitized pellets were analyzed by the methods of different heating rates, Tm-Tstop, and deconvolution. The dosimetric properties of the sensitized blue quartz pellets were also evaluated using the 220 °C TL peak.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"706 ","pages":"Article 417130"},"PeriodicalIF":2.8,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-03-08DOI: 10.1016/j.physb.2025.417129
Hussein Baqiah , Na Zhang , Mohd Mustafa Awang Kechik , Jagadeesh Pasupuleti , Bandar Ali Al-Asbahi , Naif Mohammed Al-Hada , Jianlei Yang , Qiang Li , Shicai Xu
In this paper, the impacts of chemical doping with Co ions on the microstructural, electronic and optical properties of sol-gel synthesized ErFe1-xCoxO3 thin films, where x = 0.0, 0.05, 0.1 and 0.2, were investigated. The films exhibited high crystalline orthorhombic ErFeO3 phase and showed gradual reduction of lattice parameters with Co doping. Porous microstructure was observed at x = 0.1 and 0.2. The Co ions existed in a mixed valence of Co+2 and Co3+ ions. The energy band gap (Eg) decreased from 2.79 eV for film x = 0.0–2.59 eV for film x = 0.2. The absorption coefficient reduced with Co doping in the range of 3.8–6.0 eV, however, it increased and red shifted at E < 3.8 eV. Both real refractive index and dielectric constant increased for film x = 0.05 at E > 4 eV and then decreased with further increasing of Co doping.
本文研究了化学掺杂 Co 离子对溶胶凝胶合成的 ErFe1-xCoxO3 薄膜（x = 0.0、0.05、0.1 和 0.2）的微观结构、电子和光学特性的影响。薄膜呈现出高结晶度的正方体 ErFeO3 相，并随着 Co 的掺杂，晶格参数逐渐降低。在 x = 0.1 和 0.2 时，观察到多孔的微观结构。Co 离子以 Co+2 和 Co3+ 离子的混合价存在。能带隙（Eg）从薄膜 x = 0.0 时的 2.79 eV 降至薄膜 x = 0.2 时的 2.59 eV。在 3.8-6.0 eV 范围内，随着 Co 的掺杂，吸收系数减小，但在 E < 3.8 eV 时，吸收系数增大并发生红移。在 E > 4 eV 时，薄膜 x = 0.05 的实际折射率和介电常数都有所增加，然后随着 Co 掺杂量的进一步增加而降低。
{"title":"Investigation of the microstructural and optical properties of Co doped ErFeO3 thin films synthesized via sol-gel method","authors":"Hussein Baqiah , Na Zhang , Mohd Mustafa Awang Kechik , Jagadeesh Pasupuleti , Bandar Ali Al-Asbahi , Naif Mohammed Al-Hada , Jianlei Yang , Qiang Li , Shicai Xu","doi":"10.1016/j.physb.2025.417129","DOIUrl":"10.1016/j.physb.2025.417129","url":null,"abstract":"<div><div>In this paper, the impacts of chemical doping with Co ions on the microstructural, electronic and optical properties of sol-gel synthesized ErFe<sub>1-<em>x</em></sub>Co<sub><em>x</em></sub>O<sub>3</sub> thin films, where <em>x</em> = 0.0, 0.05, 0.1 and 0.2, were investigated. The films exhibited high crystalline orthorhombic ErFeO<sub>3</sub> phase and showed gradual reduction of lattice parameters with Co doping. Porous microstructure was observed at <em>x</em> = 0.1 and 0.2. The Co ions existed in a mixed valence of Co<sup>+2</sup> and Co<sup>3+</sup> ions. The energy band gap (<em>E</em><sub>g</sub>) decreased from 2.79 eV for film <em>x</em> = 0.0–2.59 eV for film <em>x</em> = 0.2. The absorption coefficient reduced with Co doping in the range of 3.8–6.0 eV, however, it increased and red shifted at E < 3.8 eV. Both real refractive index and dielectric constant increased for film <em>x</em> = 0.05 at E > 4 eV and then decreased with further increasing of Co doping.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"706 ","pages":"Article 417129"},"PeriodicalIF":2.8,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-03-07DOI: 10.1016/j.physb.2025.417125
Kali Prasanna Mondal , Sambhunath Bera , Ajay Gupta , Dileep Kumar , Pooja Gupta , Anil Gome , V Raghavendra Reddy , Pallavi Pandit , Stephan V. Roth
The quality of organic semiconductor [tris(8-hydroxyquinoline)aluminum] Alq3 films and interface of Alq3-Co heterostructure plays a crucial role in the performance of organic spintronic devices. Four Alq3 thin films were deposited at four different substrate temperatures ranging from 30 °C to 90 °C to study the effects of deposition temperature on its structure using x-ray reflectivity (XRR) and Grazing-incidence small-angle x-ray scattering (GI-SAXS) studies. While XRR yields the internal structure of the films, GISAXS yields morphology. XRR studies reveal good-quality Alq3 films with smooth surfaces roughness less than 10 Å. Electron density gradually increases from 0.40 e/Å3 to 0.43 e/Å3 with increasing deposition temperature, which indicates continual reduction of porosity in the films. GI-SAXS studies demonstrate that with increasing deposition temperature pore separation increases from 210 Å to 810 Å and pore depth decreases progressively from 300 Å to 150 Å in the Alq3 films. To study Co diffusion into the Alq3 layer, four Si/W/Alq3/Co/Alq3 multilayers were investigated using XRR and grazing-incidence x-ray standing wave (GI-XSW) measurements simultaneously. The Alq3 layers in the multilayers were deposited at the four different substrate temperatures as mentioned above. The combined XRR & GI-XSW analysis shows that with increasing growth temperature of Alq3 layer, penetration of Co into Alq3 through Co on Alq3 interface gradually reduces from 300 Å to 130 Å with reduced concentration. This study demonstrates that by modulating the deposition temperature of Alq3 film, quality of Alq3 films and interface of Co-Alq3 heterostructures can be improved significantly, which is required for better performance of organic spintronic devices.
{"title":"Effect of deposition temperature on the quality of Alq3 films and Alq3-Co interfaces","authors":"Kali Prasanna Mondal , Sambhunath Bera , Ajay Gupta , Dileep Kumar , Pooja Gupta , Anil Gome , V Raghavendra Reddy , Pallavi Pandit , Stephan V. Roth","doi":"10.1016/j.physb.2025.417125","DOIUrl":"10.1016/j.physb.2025.417125","url":null,"abstract":"<div><div>The quality of organic semiconductor [tris(8-hydroxyquinoline)aluminum] Alq<sub>3</sub> films and interface of Alq<sub>3</sub>-Co heterostructure plays a crucial role in the performance of organic spintronic devices. Four Alq<sub>3</sub> thin films were deposited at four different substrate temperatures ranging from 30 °C to 90 °C to study the effects of deposition temperature on its structure using x-ray reflectivity (XRR) and Grazing-incidence small-angle x-ray scattering (GI-SAXS) studies. While XRR yields the internal structure of the films, GISAXS yields morphology. XRR studies reveal good-quality Alq<sub>3</sub> films with smooth surfaces roughness less than 10 Å. Electron density gradually increases from 0.40 e/Å<sup>3</sup> to 0.43 e/Å<sup>3</sup> with increasing deposition temperature, which indicates continual reduction of porosity in the films. GI-SAXS studies demonstrate that with increasing deposition temperature pore separation increases from 210 Å to 810 Å and pore depth decreases progressively from 300 Å to 150 Å in the Alq<sub>3</sub> films. To study Co diffusion into the Alq<sub>3</sub> layer, four Si/W/Alq<sub>3</sub>/Co/Alq<sub>3</sub> multilayers were investigated using XRR and grazing-incidence x-ray standing wave (GI-XSW) measurements simultaneously. The Alq<sub>3</sub> layers in the multilayers were deposited at the four different substrate temperatures as mentioned above. The combined XRR & GI-XSW analysis shows that with increasing growth temperature of Alq<sub>3</sub> layer, penetration of Co into Alq<sub>3</sub> through Co on Alq<sub>3</sub> interface gradually reduces from 300 Å to 130 Å with reduced concentration. This study demonstrates that by modulating the deposition temperature of Alq<sub>3</sub> film, quality of Alq<sub>3</sub> films and interface of Co-Alq<sub>3</sub> heterostructures can be improved significantly, which is required for better performance of organic spintronic devices.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"706 ","pages":"Article 417125"},"PeriodicalIF":2.8,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-03-06DOI: 10.1016/j.physb.2025.417089
Mustapha Madi, El Houssine Atmani, Ahmed El Manouni, Nejma Fazouan, Hamza Imtki
This study employs a density functional theory (DFT) framework to investigate the structural, electronic, and optical enhancements induced by selenium (Se) doping in antimony sulfide (Sb2S3). Se incorporation reduces the bandgap from 1.70 eV (undoped) to 1.55 eV, attributed to orbital interactions among Se-4p, S-3p, and Sb-5p, which modify the electronic structure near the conduction and valence band edges. The optical properties analysis reveals significant changes with Se doping, including an increased extinction coefficient and enhanced absorption across the ultraviolet–visible spectrum, which improves Sb2S3’s light-harvesting efficiency. Furthermore, Se doping reduces dielectric anisotropy, decreases the refractive index, and reflectivity. These findings position Se-doped Sb2S3 as a promising candidate for optoelectronic applications, offering valuable insights into non-metal doping strategies for improved solar energy conversion.
{"title":"Structural, electronic, and optical properties of undoped and Se-doped Sb2S3: A density functional theory study","authors":"Mustapha Madi, El Houssine Atmani, Ahmed El Manouni, Nejma Fazouan, Hamza Imtki","doi":"10.1016/j.physb.2025.417089","DOIUrl":"10.1016/j.physb.2025.417089","url":null,"abstract":"<div><div>This study employs a density functional theory (DFT) framework to investigate the structural, electronic, and optical enhancements induced by selenium (Se) doping in antimony sulfide (Sb<sub>2</sub>S<sub>3</sub>). Se incorporation reduces the bandgap from 1.70 eV (undoped) to 1.55 eV, attributed to orbital interactions among Se-4p, S-3p, and Sb-5p, which modify the electronic structure near the conduction and valence band edges. The optical properties analysis reveals significant changes with Se doping, including an increased extinction coefficient and enhanced absorption across the ultraviolet–visible spectrum, which improves Sb<sub>2</sub>S<sub>3</sub>’s light-harvesting efficiency. Furthermore, Se doping reduces dielectric anisotropy, decreases the refractive index, and reflectivity. These findings position Se-doped Sb<sub>2</sub>S<sub>3</sub> as a promising candidate for optoelectronic applications, offering valuable insights into non-metal doping strategies for improved solar energy conversion.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"706 ","pages":"Article 417089"},"PeriodicalIF":2.8,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
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