Pub Date : 2024-10-20DOI: 10.1016/j.mseb.2024.117769
Ao Wang , Gang Li , Cheng Li , Yujie Tang , Dong Yan , Jian Li , Lichao Jia
Using solid oxide cells to produce and utilize hydrogen is an effective method for addressing energy demands. In this study, vanadium (V) was doped into the B site of the La0.3Sr1.7Fe1.3Ni0.2Mo0.5O6-δ double perovskite, which served as the electrode material for symmetrical solid oxide cells. Doping with high-valence V4+/V5+ reduced both the average Fe valence state and the concentration of oxygen vacancies, while simultaneously decreasing the reducing activity of the material and enhancing its stability. After operating at 750 °C and ± 400 mA cm−2 for 150 h, the degradation rates for Cell-LSFNM were 4.56 % and 8.32 %, respectively, while those for Cell-LSFVNM were only 0 % and 3.32 %, respectively. Although V doping slightly diminished the electrochemical performance of the single cell, it significantly improved long-term operational stability in solid oxide fuel/electrolysis cell (SOFC/SOEC) modes.
利用固体氧化物电池生产和利用氢气是解决能源需求的有效方法。在这项研究中，钒（V）被掺杂到了 La0.3Sr1.7Fe1.3Ni0.2Mo0.5O6-δ 双包晶石的 B 位，作为对称固体氧化物电池的电极材料。高价态 V4+/V5+ 的掺杂降低了铁的平均价态和氧空位的浓度，同时降低了材料的还原活性并增强了其稳定性。在 750 °C 和 ± 400 mA cm-2 下工作 150 小时后，Cell-LSFNM 的降解率分别为 4.56 % 和 8.32 %，而 Cell-LSFVNM 的降解率仅为 0 % 和 3.32 %。虽然掺杂 V 会略微降低单电池的电化学性能，但却能显著提高固体氧化物燃料/电解电池（SOFC/SOEC）模式下的长期运行稳定性。
{"title":"Enhancing stability of double perovskite electrode by vanadium doping for symmetrical solid oxide cell","authors":"Ao Wang , Gang Li , Cheng Li , Yujie Tang , Dong Yan , Jian Li , Lichao Jia","doi":"10.1016/j.mseb.2024.117769","DOIUrl":"10.1016/j.mseb.2024.117769","url":null,"abstract":"<div><div>Using solid oxide cells to produce and utilize hydrogen is an effective method for addressing energy demands. In this study, vanadium (V) was doped into the B site of the La<sub>0.3</sub>Sr<sub>1.7</sub>Fe<sub>1.3</sub>Ni<sub>0.2</sub>Mo<sub>0.5</sub>O<sub>6-δ</sub> double perovskite, which served as the electrode material for symmetrical solid oxide cells. Doping with high-valence V<sup>4+</sup>/V<sup>5+</sup> reduced both the average Fe valence state and the concentration of oxygen vacancies, while simultaneously decreasing the reducing activity of the material and enhancing its stability. After operating at 750 °C and ± 400 mA cm<sup>−2</sup> for 150 h, the degradation rates for Cell-LSFNM were 4.56 % and 8.32 %, respectively, while those for Cell-LSFVNM were only 0 % and 3.32 %, respectively. Although V doping slightly diminished the electrochemical performance of the single cell, it significantly improved long-term operational stability in solid oxide fuel/electrolysis cell (SOFC/SOEC) modes.</div></div>","PeriodicalId":18233,"journal":{"name":"Materials Science and Engineering B-advanced Functional Solid-state Materials","volume":"310 ","pages":"Article 117769"},"PeriodicalIF":3.9,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-20DOI: 10.1016/j.mseb.2024.117760
Mehmet Selim Aslan, Gönül Akça, Selda Kılıç Çetin, Ahmet Ekicibil
In the present study, the effects of Bi doping on the Mn-site of La0.7Ca0.27Na0.03Mn1-xBixO3 perovskite manganites on their structural, magnetic, and magnetocaloric properties were investigated. From XRD analyses, the main La0.7Ca0.27Na0.03MnO3 manganite has a rhombohedral structure with space group . In contrast, manganites obtained by doping with x = 0.005, 0.01, and 0.02 Bi were found to have an orthorhombic structure with space group Pnma. The Curie temperature (TC) is 310, 246, 235, and 232 K for x = 0.0, 0.005, 0.01 and 0.02, respectively. The maximum entropy change ( values were calculated as 6.34, 8.24, 8.33, and 8.42 Jkg-1K−1 for x = 0.0, 0.005, 0.01 and 0.02, respectively. The highest Relative Cooling Power (RCP) value was computed as 271 Jkg−1 for the sample with a Bi concentration of 0.01. It was determined from the H/M versus M2 curves that all samples displayed a second-order magnetic phase transition.
{"title":"Investigation of the magnetocaloric properties of Bi doping in La0.7Ca0.27Na0.03Mn1-xBixO3 (x = 0.0, 0.005, 0.01 and 0.02) perovskites","authors":"Mehmet Selim Aslan, Gönül Akça, Selda Kılıç Çetin, Ahmet Ekicibil","doi":"10.1016/j.mseb.2024.117760","DOIUrl":"10.1016/j.mseb.2024.117760","url":null,"abstract":"<div><div>In the present study, the effects of Bi doping on the Mn-site of La<sub>0.7</sub>Ca<sub>0.27</sub>Na<sub>0.03</sub>Mn<sub>1-x</sub>Bi<sub>x</sub>O<sub>3</sub> perovskite manganites on their structural, magnetic, and magnetocaloric properties were investigated. From XRD analyses, the main La<sub>0.7</sub>Ca<sub>0.27</sub>Na<sub>0.03</sub>MnO<sub>3</sub> manganite has a rhombohedral structure with space group <span><math><mrow><mi>R</mi><mover><mrow><mn>3</mn></mrow><mrow><mo>¯</mo></mrow></mover><mi>c</mi></mrow></math></span>. In contrast, manganites obtained by doping with x = 0.005, 0.01, and 0.02 Bi were found to have an orthorhombic structure with space group <em>Pnma</em>. The Curie temperature (<em>T<sub>C</sub></em>) is 310, 246, 235, and 232 K for x = 0.0, 0.005, 0.01 and 0.02, respectively. The maximum entropy change (<span><math><mrow><mo>-</mo><mi>Δ</mi><msubsup><mi>S</mi><mrow><mi>M</mi></mrow><mrow><mi>max</mi></mrow></msubsup><mrow><mo>)</mo></mrow></mrow></math></span> values were calculated as 6.34, 8.24, 8.33, and 8.42 Jkg<sup>-1</sup>K<sup>−1</sup> for x = 0.0, 0.005, 0.01 and 0.02, respectively. The highest Relative Cooling Power (RCP) value was computed as 271 Jkg<sup>−1</sup> for the sample with a Bi concentration of 0.01. It was determined from the <em>H/M</em> versus <em>M<sup>2</sup></em> curves that all samples displayed a second-order magnetic phase transition.</div></div>","PeriodicalId":18233,"journal":{"name":"Materials Science and Engineering B-advanced Functional Solid-state Materials","volume":"310 ","pages":"Article 117760"},"PeriodicalIF":3.9,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-20DOI: 10.1016/j.mseb.2024.117755
Jiarui Jin
Metal-organic frameworks (MOFs) are utilized to integrate with TiO2 to enhance the solar-to-electricity conversion efficiency. The porphyrin-based MOF PCN-222 is the focus of the study. The MOF/TiO2 composite is deposited on a flexible ITO-PEN (polyethylene naphthalate) substrate under low-temperature (<150 °C) conditions. The resulting flexible DSSC demonstrates faster electron diffusion and improved charge carrier separation ability, achieving an efficiency of 4.41 % under 100 mW cm−2, AM 1.5 global illumination. In comparison to the traditional FTO-glass-based DSSC, this type of flexible DSSC shows great potential for application in wearable electronic devices.
{"title":"Low-temperature fabrication of metal-organic-frameworks/TiO2 photoanode for flexible dye-sensitized solar cells","authors":"Jiarui Jin","doi":"10.1016/j.mseb.2024.117755","DOIUrl":"10.1016/j.mseb.2024.117755","url":null,"abstract":"<div><div>Metal-organic frameworks (MOFs) are utilized to integrate with TiO<sub>2</sub> to enhance the solar-to-electricity conversion efficiency. The porphyrin-based MOF PCN-222 is the focus of the study. The MOF/TiO<sub>2</sub> composite is deposited on a flexible ITO-PEN (polyethylene naphthalate) substrate under low-temperature (<150 °C) conditions. The resulting flexible DSSC demonstrates faster electron diffusion and improved charge carrier separation ability, achieving an efficiency of 4.41 % under 100 mW cm<sup>−2</sup>, AM 1.5 global illumination. In comparison to the traditional FTO-glass-based DSSC, this type of flexible DSSC shows great potential for application in wearable electronic devices.</div></div>","PeriodicalId":18233,"journal":{"name":"Materials Science and Engineering B-advanced Functional Solid-state Materials","volume":"310 ","pages":"Article 117755"},"PeriodicalIF":3.9,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.mseb.2024.117730
Lu Feng , Shicheng Jin , Wanchong Li , Yan Wang , Yu Mao
The development of broadband electromagnetic wave absorbing materials often faces challenges due to constraints such as thickness and mechanical integrity. To address these issues, this study has engineered and fabricated a Short Carbon Fiber (SCF)/Bismaleimide (BMI) foam Metamaterial (MM). This composite is composed of a crosshatch metal pattern, reinforced with glass fiber plastic (GFRP), and a BMI foam matrix infused with SCF as a functional filler. The electromagnetic field distribution and input impedance analysis indicate that the crosshatch metal pattern is adept at modulating the impedance of the SCF/BMI foam, thereby influencing the field distribution. This material demonstrates superior absorption characteristics, with reflectivity levels below −10 dB across the 5–18 GHz frequency range, achieved with a mere 4.7 mm thickness. Moreover, the designed material maintains outstanding performance even under oblique incidence, and it exhibits commendable thermal stability and mechanical robustness. The findings suggest that the proposed SCF/BMI foam MM has promising potential for applications in radar stealth technology for various targets.
{"title":"Electromagnetic wave absorbing properties of Short carbon fiber/Bismaleimide foams Metamaterial","authors":"Lu Feng , Shicheng Jin , Wanchong Li , Yan Wang , Yu Mao","doi":"10.1016/j.mseb.2024.117730","DOIUrl":"10.1016/j.mseb.2024.117730","url":null,"abstract":"<div><div>The development of broadband electromagnetic wave absorbing materials often faces challenges due to constraints such as thickness and mechanical integrity. To address these issues, this study has engineered and fabricated a Short Carbon Fiber (SCF)/Bismaleimide (BMI) foam Metamaterial (MM). This composite is composed of a crosshatch metal pattern, reinforced with glass fiber plastic (GFRP), and a BMI foam matrix infused with SCF as a functional filler. The electromagnetic field distribution and input impedance analysis indicate that the crosshatch metal pattern is adept at modulating the impedance of the SCF/BMI foam, thereby influencing the field distribution. This material demonstrates superior absorption characteristics, with reflectivity levels below −10 dB across the 5–18 GHz frequency range, achieved with a mere 4.7 mm thickness. Moreover, the designed material maintains outstanding performance even under oblique incidence, and it exhibits commendable thermal stability and mechanical robustness. The findings suggest that the proposed SCF/BMI foam MM has promising potential for applications in radar stealth technology for various targets.</div></div>","PeriodicalId":18233,"journal":{"name":"Materials Science and Engineering B-advanced Functional Solid-state Materials","volume":"310 ","pages":"Article 117730"},"PeriodicalIF":3.9,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.mseb.2024.117761
Anjali Kumari , Aparna Dixit , Jisha Annie Abraham , Mumtaz Manzoor , Abhinav Kumar , Mohammad Khalid Parvez , Yedluri Anil Kumar , Abhishek Kumar Mishra , Ramesh Sharma
In this study, by implementing Full Potential augmented plane −wave (FP-LAPW) method employed in density functional theory (DFT), we computed the structural, electronic, optical, thermoelectric and elastic properties of two novel double perovskites halides Na2GeX6(X = Cl, Br). We confirmed the ground state energy and stability of these compounds by computing the cohesive and formation energies. Using the Tran Blaha modified Becke Johnson approximation and generalized gradient approximations (TB-mBJ-GGA and PBE-GGA), the electronic band structure and density of states plots of these compounds reveal their semiconducting nature. The Perdew-Burke-Ernzerhof generalized gradient approximation reveals a direct band-gap of (0.943) for Na2GeCl6 and a metallic character for Na2GeBr6 respectively. However, for Na2GeCl6 band-gap value of (3.351) with TB-mBJ, direct-bandgap value of (1.423 eV) for Na2GeBr6. The optical properties are also computed for both the compounds. The compounds show large absorption coefficient values in visible and UV regions, showing promising optoelectronic properties. Moreover, the transport properties were calculated using BoltzTrap code, which discussed about the thermoelectric behavior of the compounds.
{"title":"Tuning optoelectronic and thermoelectric attributes of Na2GeX6 (X = Br, Cl) halide double perovskites for high-efficiency solar cells applications","authors":"Anjali Kumari , Aparna Dixit , Jisha Annie Abraham , Mumtaz Manzoor , Abhinav Kumar , Mohammad Khalid Parvez , Yedluri Anil Kumar , Abhishek Kumar Mishra , Ramesh Sharma","doi":"10.1016/j.mseb.2024.117761","DOIUrl":"10.1016/j.mseb.2024.117761","url":null,"abstract":"<div><div>In this study, by implementing Full Potential augmented plane −wave (FP-LAPW) method employed in density functional theory (DFT), we computed the structural, electronic, optical, thermoelectric and elastic properties of two novel double perovskites halides Na<sub>2</sub>GeX<sub>6</sub>(X = Cl, Br). We confirmed the ground state energy and stability of these compounds by computing the cohesive and formation energies. Using the Tran Blaha modified Becke Johnson approximation and generalized gradient approximations (TB-mBJ-GGA and PBE-GGA), the electronic band structure and density of states plots of these compounds reveal their semiconducting nature. The Perdew-Burke-Ernzerhof generalized gradient approximation reveals a direct band-gap of (0.943) for Na<sub>2</sub>GeCl<sub>6</sub> and a metallic character for Na<sub>2</sub>GeBr<sub>6</sub> respectively. However, for Na<sub>2</sub>GeCl<sub>6</sub> band-gap value of (3.351) with TB-mBJ, direct-bandgap value of (1.423 eV) for Na<sub>2</sub>GeBr<sub>6</sub>. The optical properties are also computed for both the compounds. The compounds show large absorption coefficient values in visible and UV regions, showing promising optoelectronic properties. Moreover, the transport properties were calculated using BoltzTrap code, which discussed about the thermoelectric behavior of the compounds.</div></div>","PeriodicalId":18233,"journal":{"name":"Materials Science and Engineering B-advanced Functional Solid-state Materials","volume":"310 ","pages":"Article 117761"},"PeriodicalIF":3.9,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.mseb.2024.117758
Haihua Wu , Shixiong Deng , Kaixin Deng , Jiantang Jiang , Shaokang Liu , Bin Chao , Shiyu Zeng , Liang Gong , Mingmin Liu
In this paper, a ternary composite wave-absorbing material consisting of silicon carbide (SiC), natural flake graphite (NFG) and nickel (Ni) has been successfully fabricated through a combined process of selective laser sintering (SLS) and vacuum pressure impregnation. The study investigated how the content of SiC powder affected the absorption capacity and mechanical performances of the composites. The findings indicate that as the proportion of SiC powder rises, the porosity of the composites diminishes, while the bending strength increases. As the content of SiC is 40 wt%, the porosity is 52.14 % and the flexure strength is 9.58 MPa, approximately five times greater than that of graphite-type ceramic preforms. The composite’s electromagnetic wave-absorbing capability initially improves and then declines with the increase of SiC content. When the SiC content is 10 wt% and the thickness is 1.5 mm, the composite absorbing material exhibits optimal electromagnetic absorption performance, with a minimum reflection loss (RLmin)of −44.04 dB and an effective absorption bandwidth (EAB) of 5.42 GHz (8.24–13.66 GHz). The composite material, characterized by its lightweight, high strength, and broad frequency range, shows promise for applications in microwave absorption technology.
本文通过选择性激光烧结（SLS）和真空压力浸渍相结合的工艺，成功制备了一种由碳化硅（SiC）、天然鳞片石墨（NFG）和镍（Ni）组成的三元复合吸波材料。研究调查了碳化硅粉末的含量如何影响复合材料的吸收能力和机械性能。研究结果表明，随着碳化硅粉末比例的增加，复合材料的孔隙率降低，而弯曲强度增加。当 SiC 含量为 40 wt% 时，孔隙率为 52.14 %，抗弯强度为 9.58 MPa，约为石墨型陶瓷预型件的五倍。随着 SiC 含量的增加，复合材料的电磁波吸收能力先提高后下降。当 SiC 含量为 10 wt%、厚度为 1.5 mm 时，复合吸波材料表现出最佳电磁吸波性能，最小反射损耗 (RLmin) 为 -44.04 dB，有效吸波带宽 (EAB) 为 5.42 GHz (8.24-13.66 GHz)。这种复合材料具有重量轻、强度高和频率范围宽的特点，有望应用于微波吸收技术。
{"title":"Enhanced SiC/NFG/Ni ternary composite microwave absorbing materials with micro-network structures produced by selective laser sintering","authors":"Haihua Wu , Shixiong Deng , Kaixin Deng , Jiantang Jiang , Shaokang Liu , Bin Chao , Shiyu Zeng , Liang Gong , Mingmin Liu","doi":"10.1016/j.mseb.2024.117758","DOIUrl":"10.1016/j.mseb.2024.117758","url":null,"abstract":"<div><div>In this paper, a ternary composite wave-absorbing material consisting of silicon carbide (SiC), natural flake graphite (NFG) and nickel (Ni) has been successfully fabricated through a combined process of selective laser sintering (SLS) and vacuum pressure impregnation. The study investigated how the content of SiC powder affected the absorption capacity and mechanical performances of the composites. The findings indicate that as the proportion of SiC powder rises, the porosity of the composites diminishes, while the bending strength increases. As the content of SiC is 40 wt%, the porosity is 52.14 % and the flexure strength is 9.58 MPa, approximately five times greater than that of graphite-type ceramic preforms. The composite’s electromagnetic wave-absorbing capability initially improves and then declines with the increase of SiC content. When the SiC content is 10 wt% and the thickness is 1.5 mm, the composite absorbing material exhibits optimal electromagnetic absorption performance, with a minimum reflection loss (RL<sub>min</sub>)of −44.04 dB and an effective absorption bandwidth (EAB) of 5.42 GHz (8.24–13.66 GHz). The composite material, characterized by its lightweight, high strength, and broad frequency range, shows promise for applications in microwave absorption technology.</div></div>","PeriodicalId":18233,"journal":{"name":"Materials Science and Engineering B-advanced Functional Solid-state Materials","volume":"310 ","pages":"Article 117758"},"PeriodicalIF":3.9,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-17DOI: 10.1016/j.mseb.2024.117756
Mohammed Mamor , Marie Pierre Chauvat , Pierre Ruterana
An ideal metal/GaN interface is not usually possible and the surface states are often present at such interface and therefore affect the Schottky barrier diode (SBD) performance. In this work the interface states in Pt/n-type GaN SBD were extracted using temperature dependent forward current–voltage (I-V-T) characteristics over a large temperature range (80–400 K). The energy profile distribution of the density of interface states NSS (E) and its dependence on the temperature were determined from the bias and temperature dependence of the measured effective barrier height and ideality factor n (V, T). It is shown that the interface states density at room temperature decreases with increasing energy with respect to the conduction band. It is shown that the effective Schottky barrier height (SBH) and ideality factor are correlated to the density of interface states. This result suggests that interface states density contributes to barrier inhomogeneities in Pt/n-type GaN SBD. Fourier transform deep level transient spectroscopy (FT-DLTS) has been employed to extract qualitative information about the native defects present in as-grown n-type GaN. From FT-DLTS, two prominent native defects D2 and D3 were observed in GaN. The defect D2 located at EC- 0.56 eV could be associated with impurity at Ga site. The defect D3 located at EC- 0.26 eV has been assigned to nitrogen-related energy level. These native defects are interpreted as responsible of the existence of interface states and then to the barrier inhomogeneities at Pt/n-type GaN contacts. Furthermore, other possible origins of the interface states at Pt/n-type GaN interface are discussed in terms of the threading dislocations inside the GaN templates that reach the surface and other possible irregularities at this interface.
理想的金属/氮化镓界面通常是不可能的，表面态通常会出现在这种界面上，从而影响肖特基势垒二极管（SBD）的性能。在这项研究中，利用温度相关的正向电流-电压（I-V-T）特性，在较大的温度范围（80-400 K）内提取了铂/氮化镓型 SBD 的界面态。界面态密度 NSS (E) 的能谱分布及其对温度的依赖性是根据测量到的有效势垒高度 Ф0bn(V,T) 和理想度系数 n (V, T) 的偏置和温度依赖性确定的。结果表明，室温下的界面态密度随着导带能量的增加而减小。结果表明，有效肖特基势垒高度（SBH）和理想度系数与界面态密度相关。这一结果表明，界面态密度导致了 Pt/n 型氮化镓 SBD 的势垒不均匀性。傅立叶变换深电平瞬态光谱法（FT-DLTS）被用来提取有关生长中的 n 型氮化镓中存在的原生缺陷的定性信息。从 FT-DLTS 中观察到氮化镓中存在两个突出的原生缺陷 D2 和 D3。位于 EC- 0.56 eV 的缺陷 D2 可能与 Ga 位点的杂质有关。位于 EC- 0.26 eV 的缺陷 D3 被归入与氮有关的能级。这些原生缺陷被解释为界面态存在的原因，进而导致铂/氮型氮化镓接触的势垒不均匀性。此外，还讨论了铂/氮型氮化镓界面态的其他可能来源，包括氮化镓模板内部到达表面的穿线位错以及该界面上其他可能的不规则性。
{"title":"Electrical and structural investigation of Pt/n-type GaN Schottky contacts: The possible origin of inhomogeneous barrier","authors":"Mohammed Mamor , Marie Pierre Chauvat , Pierre Ruterana","doi":"10.1016/j.mseb.2024.117756","DOIUrl":"10.1016/j.mseb.2024.117756","url":null,"abstract":"<div><div>An ideal metal/GaN interface is not usually possible and the surface states are often present at such interface and therefore affect the Schottky barrier diode (SBD) performance. In this work the interface states in Pt/n-type GaN SBD were extracted using temperature dependent forward current–voltage (<em>I</em>-<em>V</em>-<em>T</em>) characteristics over a large temperature range (80–400 K). The energy profile distribution of the density of interface states <em>N</em><sub>SS</sub> (<em>E</em>) and its dependence on the temperature were determined from the bias and temperature dependence of the measured effective barrier height <span><math><mrow><msub><mrow><mi>Ф</mi></mrow><mrow><mn>0</mn><mi>b</mi><mi>n</mi></mrow></msub><mo>(</mo><mi>V</mi><mo>,</mo><mi>T</mi><mo>)</mo></mrow></math></span> and ideality factor <em>n</em> (<em>V</em>, <em>T</em>). It is shown that the interface states density at room temperature decreases with increasing energy with respect to the conduction band. It is shown that the effective Schottky barrier height (SBH) and ideality factor are correlated to the density of interface states. This result suggests that interface states density contributes to barrier inhomogeneities in Pt/n-type GaN SBD. Fourier transform deep level transient spectroscopy (FT-DLTS) has been employed to extract qualitative information about the native defects present in as-grown n-type GaN. From FT-DLTS, two prominent native defects D<sub>2</sub> and D<sub>3</sub> were observed in GaN. The defect D<sub>2</sub> located at <em>E</em><sub>C</sub>- 0.56 eV could be associated with impurity at Ga site. The defect D<sub>3</sub> located at <em>E</em><sub>C</sub>- 0.26 eV has been assigned to nitrogen-related energy level. These native defects are interpreted as responsible of the existence of interface states and then to the barrier inhomogeneities at Pt/n-type GaN contacts. Furthermore, other possible origins of the interface states at Pt/n-type GaN interface are discussed in terms of the threading dislocations inside the GaN templates that reach the surface and other possible irregularities at this interface.</div></div>","PeriodicalId":18233,"journal":{"name":"Materials Science and Engineering B-advanced Functional Solid-state Materials","volume":"310 ","pages":"Article 117756"},"PeriodicalIF":3.9,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-17DOI: 10.1016/j.mseb.2024.117763
Suyin Zhang, Qinhua Wei, Hang Yin, Gao Tang, Laishun Qin
This work reports the luminescence spectra and application of novel Eu3+-doped Na2MgGd2[SiO3]4F2 phosphor. The X-ray powder diffraction confirmed the pure phase formation of the samples with the monoclinic space group P21/c (No:14). The phosphors demonstrated efficient red emission at 613 nm from the electric dipole transitions 5D0→7F2. The optimal doping concentration was found to be approximately 25 mol%. Na2MgGd2[SiO3]4F2:0.25Eu3+ exhibits a high quantum efficiency (QE) of 57 % with excellent thermal stability and pure chromaticity. Red- and the white light-emitting diode devices were packaged using InGaN chips and Na2MgGd2[SiO3]4F2:0.25Eu3+. The fabricated WLED has CIE coordinates of (x = 0.33, y = 0.34), which are very close to the white point in the National Television System Committee (x = 0.33, y = 0.33). The color rendering index (CRI, Ra) and correlated color temperature (CCT) of the WLED are 91 and 4400 K, respectively. The results show that as a red luminescent phosphor, it is a potential candidate for the preparation of near-UV/blue InGaN-based WLEDs.
{"title":"Spectral characteristics and luminescence applications of Eu3+-activated fluorosilicate Na2MgGd2[SiO3]4F2","authors":"Suyin Zhang, Qinhua Wei, Hang Yin, Gao Tang, Laishun Qin","doi":"10.1016/j.mseb.2024.117763","DOIUrl":"10.1016/j.mseb.2024.117763","url":null,"abstract":"<div><div>This work reports the luminescence spectra and application of novel Eu<sup>3+</sup>-doped Na<sub>2</sub>MgGd<sub>2</sub>[SiO<sub>3</sub>]<sub>4</sub>F<sub>2</sub> phosphor. The X-ray powder diffraction confirmed the pure phase formation of the samples with the monoclinic space group <em>P</em>2<sub>1</sub>/c (No:14). The phosphors demonstrated efficient red emission at 613 nm from the electric dipole transitions <sup>5</sup>D<sub>0</sub>→<sup>7</sup>F<sub>2</sub>. The optimal doping concentration was found to be approximately 25 mol%. Na<sub>2</sub>MgGd<sub>2</sub>[SiO<sub>3</sub>]<sub>4</sub>F<sub>2</sub>:0.25Eu<sup>3+</sup> exhibits a high quantum efficiency (QE) of 57 % with excellent thermal stability and pure chromaticity. Red- and the white light-emitting diode devices were packaged using InGaN chips and Na<sub>2</sub>MgGd<sub>2</sub>[SiO<sub>3</sub>]<sub>4</sub>F<sub>2</sub>:0.25Eu<sup>3+</sup>. The fabricated WLED has CIE coordinates of (<em>x</em> = 0.33, y = 0.34), which are very close to the white point in the National Television System Committee (<em>x</em> = 0.33, <em>y</em> = 0.33). The color rendering index (CRI, Ra) and correlated color temperature (CCT) of the WLED are 91 and 4400 K, respectively. The results show that as a red luminescent phosphor, it is a potential candidate for the preparation of near-UV/blue InGaN-based WLEDs.</div></div>","PeriodicalId":18233,"journal":{"name":"Materials Science and Engineering B-advanced Functional Solid-state Materials","volume":"310 ","pages":"Article 117763"},"PeriodicalIF":3.9,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.1016/j.mseb.2024.117754
Naima, Pawan K. Tyagi, Vinod Singh
In this report, the optimization of various parameters of electron/hole collection layer, buffer layer and active layer of the HIT solar cell have been carried out by using AFORS-HET software. Novelty of the reported work is the use of doped diamane as an effective electron/hole collection layers for the enhanced performance of the HIT solar cell. Here, n and p-type diamane layers are used as the electron/hole collection layers or the emitter and back surface field (BSF) layer, respectively. Considering the absorption loss at the front contact, the maximum efficiency (η) for the fully optimized cell is found 27.88 % with open circuit voltage (VOC) 691.1 mV, current density (JSC) 49.3 mA/ and fill factor (FF) 81.83 % whereas, in conventional HIT cell with η of 25.6 % and JSC of 41.8 mA/cm2 reported by Masuko et. al. [7]. If zero absorption loss is considered, the efficiency could exceed its theoretical limit. A detailed study has also been done on the role of texturing angle and absorption loss found at the front contact of the solar cell.
本报告使用 AFORS-HET 软件对 HIT 太阳能电池的电子/空穴收集层、缓冲层和活性层的各种参数进行了优化。报告工作的新颖之处在于使用掺杂二元胺作为有效的电子/空穴收集层，以提高 HIT 太阳能电池的性能。在这里，n 型和 p 型二元胺层分别用作电子/空穴收集层或发射极和背表面场（BSF）层。考虑到前触点的吸收损耗，完全优化电池的最高效率（η）为 27.88%，开路电压（VOC）为 691.1 mV，电流密度（JSC）为 49.3 mA/cm2，填充因子（FF）为 81.83%，而 Masuko 等人[7]报告的传统 HIT 电池的最高效率（η）为 25.6%，电流密度（JSC）为 41.8 mA/cm2。如果考虑零吸收损耗，效率可能会超过理论极限。此外，还对太阳能电池前触点的纹理角度和吸收损耗的作用进行了详细研究。
{"title":"Doped diamane: An efficient electron/hole collection layer in HIT solar cell","authors":"Naima, Pawan K. Tyagi, Vinod Singh","doi":"10.1016/j.mseb.2024.117754","DOIUrl":"10.1016/j.mseb.2024.117754","url":null,"abstract":"<div><div>In this report, the optimization of various parameters of electron/hole collection layer, buffer layer and active layer of the HIT solar cell have been carried out by using AFORS-HET software. Novelty of the reported work is the use of doped diamane as an effective electron/hole collection layers for the enhanced performance of the HIT solar cell. Here, n and p-type diamane layers are used as the electron/hole collection layers or the emitter and back surface field (BSF) layer, respectively. Considering the absorption loss at the front contact, the maximum efficiency (η) for the fully optimized cell is found 27.88 % with open circuit voltage (V<sub>OC</sub>) 691.1 mV, current density (J<sub>SC</sub>) 49.3 mA/<span><math><msup><mtext>cm</mtext><mn>2</mn></msup></math></span> and fill factor (FF) 81.83 % whereas, in conventional HIT cell with η of 25.6 % and J<sub>SC</sub> of 41.8 mA/cm<sup>2</sup> reported by Masuko et. al. <span><span>[7]</span></span>. If zero absorption loss is considered, the efficiency could exceed its theoretical limit. A detailed study has also been done on the role of texturing angle and absorption loss found at the front contact of the<!--> <!-->solar cell.</div></div>","PeriodicalId":18233,"journal":{"name":"Materials Science and Engineering B-advanced Functional Solid-state Materials","volume":"310 ","pages":"Article 117754"},"PeriodicalIF":3.9,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-13DOI: 10.1016/j.mseb.2024.117739
Wenzhen Wang , Sirui Bao , Chengxiong Gao , Taocheng Huang , Yan Zhu , Run Xu
The ternary chalcogenide compound AgBiS2 has garnered significant attention from researchers due to its unique properties. It has the characteristics of adjustable bandgap, high absorption coefficient, good environmental stability, and easy processing. The methods for the preparation of AgBiS2 powder are mainly focused on chemical methods, with silver nitrate commonly used as the silver source despite its toxic nature and harmful impact on health and the environment. In this paper, AgBiS2 powder was prepared by the solvothermal method using silver acetate, and the prepared powder samples were used to simulate the photocatalytic degradation of methylene blue (MB) solution under sunlight irradiation to explore its photocatalytic degradation efficiency. The prepared AgBiS2 powder mainly exists in two forms: nanorods with a length of more than 5 μm and nanoparticles with a diameter of about 200 nm, and the topography changes with temperature. The morphology of AgBiS2 grown at 160 °C was similar to that of tabular accumulation, and when grown at 180 °C, small AgBiS2 particles accumulate on larger plates. The degradation efficiency of AgBiS2 powder reached 44.38 % after 4 h of photocatalytic degradation, which was three times higher than that of the blank sample. The reaction rate constant is 0.0024, which is much higher than that of the blank sample. Therefore, AgBiS2 powder has great potential in photocatalytic degradation and is expected to be an efficient photocatalyst.
{"title":"Preparation of AgBiS2 powder and its photocatalytic performance","authors":"Wenzhen Wang , Sirui Bao , Chengxiong Gao , Taocheng Huang , Yan Zhu , Run Xu","doi":"10.1016/j.mseb.2024.117739","DOIUrl":"10.1016/j.mseb.2024.117739","url":null,"abstract":"<div><div>The ternary chalcogenide compound AgBiS<sub>2</sub> has garnered significant attention from researchers due to its unique properties. It has the characteristics of adjustable bandgap, high absorption coefficient, good environmental stability, and easy processing. The methods for the preparation of AgBiS<sub>2</sub> powder are mainly focused on chemical methods, with silver nitrate commonly used as the silver source despite its toxic nature and harmful impact on health and the environment. In this paper, AgBiS<sub>2</sub> powder was prepared by the solvothermal method using silver acetate, and the prepared powder samples were used to simulate the photocatalytic degradation of methylene blue (MB) solution under sunlight irradiation to explore its photocatalytic degradation efficiency. The prepared AgBiS<sub>2</sub> powder mainly exists in two forms: nanorods with a length of more than 5 μm and nanoparticles with a diameter of about 200 nm, and the topography changes with temperature. The morphology of AgBiS<sub>2</sub> grown at 160 °C was similar to that of tabular accumulation, and when grown at 180 °C, small AgBiS<sub>2</sub> particles accumulate on larger plates. The degradation efficiency of AgBiS<sub>2</sub> powder reached 44.38 % after 4 h of photocatalytic degradation, which was three times higher than that of the blank sample. The reaction rate constant is 0.0024, which is much higher than that of the blank sample. Therefore, AgBiS<sub>2</sub> powder has great potential in photocatalytic degradation and is expected to be an efficient photocatalyst.</div></div>","PeriodicalId":18233,"journal":{"name":"Materials Science and Engineering B-advanced Functional Solid-state Materials","volume":"310 ","pages":"Article 117739"},"PeriodicalIF":3.9,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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