Superlattices and Microstructures最新文献_第6页

An intriguing canting dipole configuration and its evolution under an electric field in La-doped Pb(Zr,Sn,Ti)O3 perovskites la掺杂Pb(Zr,Sn,Ti)O3钙钛矿中一个有趣的倾斜偶极子结构及其在电场下的演变

IF 3.1 3区物理与天体物理

Superlattices and Microstructures Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2022.03

B. Gao, Hui Liu, Zhengyang Zhou, Ke Xu, He Qi, Shiqing Deng, Yang Ren, Junliang Sun, Houbing Huang, Jun Chen

{"title":"An intriguing canting dipole configuration and its evolution under an electric field in La-doped Pb(Zr,Sn,Ti)O3 perovskites","authors":"B. Gao, Hui Liu, Zhengyang Zhou, Ke Xu, He Qi, Shiqing Deng, Yang Ren, Junliang Sun, Houbing Huang, Jun Chen","doi":"10.20517/microstructures.2022.03","DOIUrl":"https://doi.org/10.20517/microstructures.2022.03","url":null,"abstract":"Despite the fact that electric dipole ordering plays a key role in the unique physical properties of dielectric materials, electric dipole configurations mostly appear simply as either parallel or antiparallel. Here, we report a canting electric dipole configuration in La-doped Pb(Zr,Sn,Ti)O3 perovskites based on advanced neutron, synchrotron X-ray and three-dimensional electron diffraction techniques. It is revealed that, arising from the coupling between the atomic displacement and oxygen octahedral tilting, this unique electric dipole configuration displays a canting arrangement aligned in the (110)p plane that possesses an antiparallel component along the [110]P direction and a parallel component along the [001]P direction. Remarkably, under an in-situ electric field, the electric dipoles continuously rotate with a gradually reduced canting angle, as confirmed by phase-field simulations, and ultimately evolve into a ferroelectric ordering. Such an evolution gives rises to a small hysteresis and an equivalent lattice strain to the macroscopic strain. These findings enrich the current understanding of the types of electric dipole configurations in dielectric materials and are expected to aid the design of new dielectric materials with emergent properties.","PeriodicalId":22044,"journal":{"name":"Superlattices and Microstructures","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74542355","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}

引用次数: 4

Near-room-temperature reversible switching of quadratic optical nonlinearities in a one-dimensional perovskite-like hybrid 一维钙钛矿类杂化材料中二次光学非线性的近室温可逆开关

IF 3.1 3区物理与天体物理

Superlattices and Microstructures Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2022.09

Qing-bin Fan, Yu Ma, Haojie Xu, Yipeng Song, Yi Liu, Junhua Luo, Zhihua Sun

{"title":"Near-room-temperature reversible switching of quadratic optical nonlinearities in a one-dimensional perovskite-like hybrid","authors":"Qing-bin Fan, Yu Ma, Haojie Xu, Yipeng Song, Yi Liu, Junhua Luo, Zhihua Sun","doi":"10.20517/microstructures.2022.09","DOIUrl":"https://doi.org/10.20517/microstructures.2022.09","url":null,"abstract":"The switching of quadratic nonlinear optical (NLO) effects between two or more NLO states of solid-state materials represents an intriguing new branch in the field of photoelectrics and optics. While structural phase transitions have shown potential in this field, near-room-temperature reversible NLO switches have rarely been reported. To exploit new NLO switching materials within the structurally flexible class of hybrid perovskites, here, we synthesize a one-dimensional perovskite-like hybrid, (MP)PbBr3 (where MP+ is a 1-methylpyrrolidinium cation), through a facile solution method, which exhibits strong second harmonic generation (SHG) activities with an intensity of ~1.6 times as large as potassium dihydrogen phosphate. Intriguingly, (MP)PbBr3 enables the near-room temperature reversible switching of SHG properties, showing a large NLO switching contrast of up to ~40 between its SHG-active and SHG-inactive phases, beyond most of its liquid counterparts. Further microscopic structural analyses reveal that the dynamic ordering of the organic MP+ cation and inorganic chain-like skeleton triggers its centrosymmetric (P63/mmc) to acentric (P212121) phase transition at 316 K upon cooling, resulting in a crucial contribution to its NLO switching properties. This work illustrates the potential of this material as a candidate for solid-state NLO switches and will promote the development of NLO materials within the family of low-dimensional hybrid perovskites.","PeriodicalId":22044,"journal":{"name":"Superlattices and Microstructures","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73444026","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}

引用次数: 2

Tunable negative thermal expansion in La(Fe, Si)13/resin composites with high mechanical property and long-term cycle stability La(Fe, Si)13/树脂复合材料的可调负热膨胀，具有高力学性能和长期循环稳定性

IF 3.1 3区物理与天体物理

Superlattices and Microstructures Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2022.13

He Zhou, Yuwei Liu, Rongjin Huang, Bo Chen, Min Xia, Ziyuan Yu, Haodong Chen, K. Qiao, J. Cong, S. Taskaev, K. Chu, Hu Zhang

{"title":"Tunable negative thermal expansion in La(Fe, Si)13/resin composites with high mechanical property and long-term cycle stability","authors":"He Zhou, Yuwei Liu, Rongjin Huang, Bo Chen, Min Xia, Ziyuan Yu, Haodong Chen, K. Qiao, J. Cong, S. Taskaev, K. Chu, Hu Zhang","doi":"10.20517/microstructures.2022.13","DOIUrl":"https://doi.org/10.20517/microstructures.2022.13","url":null,"abstract":"Materials with tunable negative thermal expansion (NTE) are highly demanded in various functional devices. La(Fe, Si)13-based compounds are promising NTE materials due to their outstanding NTE properties. However, their poor mechanical properties and related short service life restrict their practical applications. In this work, epoxy resin with positive thermal expansion is used to synthesize La-Fe-Si/resin composites. The NTE of La-Fe-Si/resin composites can be manipulated by optimizing the La-Fe-Si particle size and resin content, and tailoring resin content could tune the NTE more effectively. The average linear coefficient of thermal expansion of the composites decreases from -275.0 × 10-6 K-1 to -4.9 × 10-6 K-1 over the magnetic transition temperature range as the resin content increases from 3 wt.% to 80 wt.%. In addition, zero thermal expansion is achieved in the La-Fe-Si/resin composite with 20 wt.% resin. The resin would reinforce the binding force by filling the pores between the particles. The La-Fe-Si/resin composite with 80 wt.% resin exhibits highly improved mechanical properties; for example, its compressive strength of 205 MPa is 75% higher than that of the La-Fe-Si/resin composite with 3 wt.% resin. The prepared La-Fe-Si/resin composites can be machined into different shapes for practical applications, such as thin plates, strips, and rods. Furthermore, the La-Fe-Si/resin composites can undergo 1000 thermal cycles without NTE performance degradation and mechanical integrity loss, indicating durable cycle stability. Hence, significantly tunable NTE with high mechanical properties and long-term cycle stability makes La-Fe-Si/resin composites present great application potential as NTE materials.","PeriodicalId":22044,"journal":{"name":"Superlattices and Microstructures","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87430927","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}

引用次数: 2

BaTiO3-NaNbO3 energy storage ceramics with an ultrafast charge-discharge rate and temperature-stable power density 具有超快充放电速率和温度稳定功率密度的BaTiO3-NaNbO3储能陶瓷

IF 3.1 3区物理与天体物理

Superlattices and Microstructures Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2022.21

Peiyao Zhao, Longtu Li, Xiao-hui Wang, Prof. Xiaohui Wang, Shiqing Deng, R. Zuo, Shujun Zhang

{"title":"BaTiO3-NaNbO3 energy storage ceramics with an ultrafast charge-discharge rate and temperature-stable power density","authors":"Peiyao Zhao, Longtu Li, Xiao-hui Wang, Prof. Xiaohui Wang, Shiqing Deng, R. Zuo, Shujun Zhang","doi":"10.20517/microstructures.2022.21","DOIUrl":"https://doi.org/10.20517/microstructures.2022.21","url":null,"abstract":"Dielectric capacitors with ultrafast charge-discharge rates are extensively used in electrical and electronic systems. To meet the growing demand for energy storage applications, researchers have devoted significant attention to dielectric ceramics with excellent energy storage properties. As a result, the awareness of the importance of the pulsed discharge behavior of dielectric ceramics and conducting characterization studies has been raised. However, the temperature stability of pulsed discharge behavior, which is significant for pulsed power applications, is still not given the necessary consideration. Here, we systematically investigate the microstructures, energy storage properties and discharge behaviors of nanograined (1-x)BaTiO3-xNaNbO3 ceramics prepared by a two-step sintering method. The 0.60BaTiO3-0.40NaNbO3 ceramics with relaxor ferroelectric characteristics possess an optimal discharge energy density of 3.07 J cm-3, a high energy efficiency of 92.6%, an ultrafast discharge rate of 39 ns and a high power density of 100 MW cm-3. In addition to stable energy storage properties in terms of frequency, fatigue and temperature, the 0.60BaTiO3-0.40NaNbO3 ceramics exhibit temperature-stable power density, thereby illustrating their significant potential for power electronics and pulsed power applications.","PeriodicalId":22044,"journal":{"name":"Superlattices and Microstructures","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79983053","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}

引用次数: 6

Design of super-elastic freestanding ferroelectric thin films guided by phase-field simulations 基于相场模拟的超弹性独立铁电薄膜设计

IF 3.1 3区物理与天体物理

Superlattices and Microstructures Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2022.20

Changqing Guo, Houbing Huang

引用次数: 2

Modulation of photogenerated holes for enhanced photoelectrocatalytic performance 提高光电催化性能的光生孔调制

IF 3.1 3区物理与天体物理

Superlattices and Microstructures Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2022.23

N. Liu, Yixian Liu, Yunliang Liu, Yaxi Li, Yuanyuan Cheng, Hai-tao Li

{"title":"Modulation of photogenerated holes for enhanced photoelectrocatalytic performance","authors":"N. Liu, Yixian Liu, Yunliang Liu, Yaxi Li, Yuanyuan Cheng, Hai-tao Li","doi":"10.20517/microstructures.2022.23","DOIUrl":"https://doi.org/10.20517/microstructures.2022.23","url":null,"abstract":"Utilizing clean energy derived from photoelectrocatalytic reactions is expected to be an excellent choice to fundamentally solve the problem of the human energy crisis. Photoelectrochemical (PEC) cell can effectively promote charge separation and improve solar energy conversion efficiency since it combines the advantages of photocatalysis and electrocatalysis. However, the hole transfer and subsequent oxidation reaction in the PEC process are slow, resulting in the rapid recombination of photogenerated electron-hole pairs and low PEC performance. The half-oxidation reaction involving photogenerated holes is the bottleneck of PEC water splitting. Therefore, hole modulation has been an important research area in the field of catalysis. However, compared with electron modulation, research on hole modulation is limited and still faces great challenges. It is therefore of great significance to develop effective modulation strategies for photogenerated holes. This review summarizes the hole modulation strategies developed in the last five years, including hole sacrificial agents, nanostructural modification, heterostructure construction and cocatalyst modification. Hole modulation dynamics studies, such as transient absorption spectroscopy, time-resolved photoluminescence spectroscopy, transient photovoltage and scanning electrochemical microscopy, are also summarized. Moreover, relevant conclusions and an outlook are proposed.","PeriodicalId":22044,"journal":{"name":"Superlattices and Microstructures","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83267360","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}

引用次数: 5

Performance optimization of single graded CIGS absorber and buffer layers for high efficiency: A numerical approach 单梯度CIGS吸收体和高效缓冲层的性能优化:数值方法

IF 3.1 3区物理与天体物理

Superlattices and Microstructures Pub Date : 2022-01-01 DOI: 10.1016/j.spmi.2021.107094

R. Prasad, Rajarshi Pal, Udai P. Singh

{"title":"Performance optimization of single graded CIGS absorber and buffer layers for high efficiency: A numerical approach","authors":"R. Prasad, Rajarshi Pal, Udai P. Singh","doi":"10.1016/j.spmi.2021.107094","DOIUrl":"10.1016/j.spmi.2021.107094","url":null,"abstract":"<div>We present a numerical simulation based study of single graded Cu(In,Ga)Se2 (Copper Indium Gallium Diselenide) thin film solar cell. In this work, initially a basic CIGS single graded cell structure is optimized in terms of thickness, band-gap and doping concentration. CdS is kept as the buffer layer, which is widely used for high efficiency CIGS solar cells. In the next step, CdS is replaced with ZnMgO as the buffer layer in order to exploit its greater photon absorption ability due to its higher band-gap which further enhances the cell efficiency. A thorough analysis is carried out on the solar cell parameters open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF) and quantum efficiency (η) of the photovoltaic cell structure. An intermediate layer of p-type MoS2 is inserted in between the single graded CIGS absorber layers. The objective is to limit the unintentional Ga inter diffusion and maintain the desired grading during the high temperature annealing for the absorber preparation. The power conversion efficiency of the bilayer device structure with Ga fraction x=(0.31) of the top absorber layer along with Ga fraction y=(0.25) of the bottom absorber layer exhibits an improved efficiency from 24.02% (CdS as the buffer layer) to 25.37% (ZnMgO as buffer layer). An excellent power efficiency of η = 26.78% is reported after adding the intermediate layer of p-type MoS2 and optimizing its thickness and the carrier concentration.</div>","PeriodicalId":22044,"journal":{"name":"Superlattices and Microstructures","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45121827","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}

引用次数: 8

Normally-off AlGaN/AlN/GaN HEMT with a composite recessed gate 常关AlGaN/AlN/GaN HEMT与复合凹槽栅极

IF 3.1 3区物理与天体物理

Superlattices and Microstructures Pub Date : 2022-01-01 DOI: 10.1016/j.spmi.2021.107064

Jialin Li , Yian Yin , Ni Zeng , Fengbo Liao , Mengxiao Lian , Xichen Zhang , Keming Zhang , Jingbo Li

{"title":"Normally-off AlGaN/AlN/GaN HEMT with a composite recessed gate","authors":"Jialin Li , Yian Yin , Ni Zeng , Fengbo Liao , Mengxiao Lian , Xichen Zhang , Keming Zhang , Jingbo Li","doi":"10.1016/j.spmi.2021.107064","DOIUrl":"10.1016/j.spmi.2021.107064","url":null,"abstract":"<div>As we all know, the normally-off HEMT is very important to the safety of power electronic systems. To increase the threshold voltage of the device, this article proposes to cover Al2O3 on the recessed P-GaN to form the recessed p-GaN HEMT covered with Al2O3. Through simulation calculation, covering Al2O3 on P-GaN can effectively increase the threshold voltage, but the saturation current and transconductance will be severely reduced. Therefore, this article optimizes the structure and proposes a composite recessed-gate HEMT for the first time. It can obtain high saturation current and high transconductance while maintaining a high threshold voltage. Compared with the recessed p-GaN HEMT covered with Al2O3, the transconductance and saturation current of the composite recessed-gate HEMT are increased by 13.14% and 121.33%, respectively, while the threshold voltage is only reduced by 4.44% (4.3 V). In addition, the gate dielectric has a greater impact on device performance. Therefore, this paper analyzes the influence of the thickness of the Al2O3 layer on the device through theoretical calculations and obtains the optimal value of the thickness. (T1 = 18.3 nm, Vth = 4.5 V, Isat = 456 mA/mm). The results show that the composite recessed gate has broad application prospects in the next generation of normally-off power device applications.</div>","PeriodicalId":22044,"journal":{"name":"Superlattices and Microstructures","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47505236","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}

引用次数: 5

Topochemical synthesis and structural characteristics of orientation-controlled (Bi0.5Na0.5)0.94Ba0.06TiO3 perovskite microplatelets 取向可控(Bi0.5Na0.5)0.94Ba0.06TiO3钙钛矿微血小板的拓扑化学合成及结构特性

IF 3.1 3区物理与天体物理

Superlattices and Microstructures Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2021.13

Yaqing Ma, H. Xie, Yuan Sun, Q. Kou, Linjing Liu, Bin Yang, W. Cao, Yunfei Chang, Feifang Li

引用次数: 1

Ultrasonication-assisted fabrication of porous ZnO@C nanoplates for lithium-ion batteries 锂离子电池用多孔ZnO@C纳米板的超声辅助制备

IF 3.1 3区物理与天体物理

Superlattices and Microstructures Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2022.11

Xueting Wang, Yunchuang Wang, Mei-Yueh Wu, Ruopian Fang, Xi Yang, Da-Wei Wang

引用次数: 2