Strong Bulk Photovoltaic Effect in Planar Barium Titanate Thin Films
Andrew L. Bennett-Jackson, Or Shafir, A. R. Will-Cole, Atanu Samanta, Dongfang Chen, Adrian Podpirka, Aaron Burger, Liyan Wu, Eduardo Lupi Sosa, Lane W. Martin,… 展开作者
Andrew L. Bennett-Jackson, Or Shafir, A. R. Will-Cole, Atanu Samanta, Dongfang Chen, Adrian Podpirka, Aaron Burger, Liyan Wu, Eduardo Lupi Sosa, Lane W. Martin, Jonathan E. Spanier, Ilya Grinberg
The bulk photovoltaic effect (BPE) leads to the generation of a photocurrent from an asymmetric material. Despite drawing much attention due to its ability to generate photovoltages above the band gap ($E_g$), it is considered a weak effect due to the low generated photocurrents. Here, we show that a remarkably high photoresponse can be achieved by exploiting the BPE in simple planar BaTiO$_3$ (BTO) films, solely by tuning their fundamental ferroelectric properties via strain and growth orientation induced by epitaxial growth on different substrates. We find a non-monotonic dependence of the responsivity ($R_{\rm SC}$) on the ferroelectric polarization ($P$) and obtain a remarkably high BPE coefficient ($β$) of $\approx$10$^{-2}$ 1/V, which to the best of our knowledge is the highest reported to date for standard planar BTO thin films. We show that the standard first-principles-based descriptions of BPE in bulk materials cannot account for the photocurrent trends observed for our films and therefore propose a novel mechanism that elucidates the fundamental relationship between $P$ and responsivity in ferroelectric thin films. Our results suggest that practical applications of ferroelectric photovoltaics in standard planar film geometries can be achieved through careful joint optimization of the bulk structure, light absorption, and electrode-absorber interface properties.
Comment on ``Conduction states in oxide perovskites: Three manifestations of Ti$^{3 +}$ Jahn-Teller polarons in barium titanate''
在这篇评论中，[S。伦耶尔岛F. Schirmer，H. Hesse和Th. W. Kool，Phys. Rev. B { \bf 66}，165106（2002）]讨论了钙钛矿中氧空位的电子结构。第一原理计算支持这些空位中的深能级，而Lenjer等人认为电子的相互作用能是负的，但电导率的数据则相反。
Goldstone-mediated polar instability in hexagonal barium titanate
University of Warwick（华威大学）；Durham University（杜伦大学）；Luxembourg Institute of Science and Technology（卢森堡科学与技术研究所）；European Synchrotron Radiation Facility（欧洲同步辐射装置）；Institut Laue-Langevin（朗之万研究所）
Electrical Studies of Barkhausen Switching Noise in Ferroelectric lead zirconate titanate (PZT) and BaTiO3: Critical Exponents and Temperature-dependence
Theoretical investigation of electronic, optical and thermoelectric properties of tellurium doped barium titanate (BTO) through modified Becke Johnson exchange potential
Electric Charge Transport and Dielectric Properties of the Barium Titanate Ceramics Obtained by Spark-Plasma Sintering with Different Carbon Content
Institute of Physics of the National Academy of Sciences of Ukraine（乌克兰国家科学院物理研究所）；Educational Scientific Institute of High Technologies, Taras Shevchenko National University of Kyiv（基辅塔拉斯舍甫琴科国立大学高等技术教育科学研究所）；Frantsevich Institute for Problems in Materials Science, National Academy of Sciences of Ukraine（乌克兰国家科学院弗兰采维奇材料科学问题研究所）；Department of Chemistry, Stockholm University（斯德哥尔摩大学化学系）；Department of Physical Materials Science and Heat Treatment, National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”（乌克兰国立技术大学“伊戈尔·西科尔斯基基辅理工学院”物理材料科学与热处理系）
Impact of Carbon Contamination on the Low-Temperature Electric Conduction of the Spark-Plasma Sintered Barium Titanate Ceramics
Institute of Physics of the National Academy of Sciences of Ukraine（乌克兰国家科学院物理研究所）；Frantsevich Institute for Problems in Materials Science, National Academy of Sciences of Ukraine（乌克兰国家科学院弗兰特谢维奇材料科学问题研究所）；V. Lashkarev Institute of Semiconductor Physics, National Academy of Sciences of Ukraine（乌克兰国家科学院瓦·拉舍列夫半导体物理研究所）
Hybrid Barium Titanate Waveguide Designs For Efficient Nonlinear Frequency Conversion
Fraunhofer Institute for Applied Optics and Precision Engineering IOF（弗劳恩霍夫应用光学和精密工程研究所）；Institute of Applied Physics, Abbe Center of Photonics, Friedrich Schiller University Jena（耶拿弗里德里希·席勒大学阿贝光子学中心应用物理研究所）；Max Planck School of Photonics（马克斯·普朗克光子学校）
Larger photovoltaic effect and hysteretic photocarrier dynamics in Pb[(Mg1/3Nb2/3)0.70Ti0.30]O3 crystal
在最近发现的Pb[（Mg 1/3 Nb 2/3）0.68Ti0.32]O3晶体中的体光伏效应之后，我们在这里报告了在相关的组成Pb[（Mg 1/3 Nb 2/3）0.7Ti0.30]O3中的光致变色性以及其极化依赖性的一个数量级以上的改善。光电流测量与光强度揭示了一个迷人的滞后载流子动力学清楚地表明电荷产生，捕获和释放过程。
我们报道了几个国家的团体独立发明的铁电纳米管。器件已经用三种不同的材料制成：锆钛酸铅PbZr 1-xTixO 3（PZT）;钛酸钡BaTiO 3;和钽酸锶铋SrBi 2 Ta 2 O 9（SBT）。几种不同的沉积技术已经成功地使用，包括雾化CSD（化学溶液沉积）和孔隙润湿。铁电滞后和高的光学非线性已被证明。通过SEM、TEM、XRD、AFM（压电模式）和SHG分析了结构。沟槽在硅动态随机存取存储器，喷墨打印机和光子器件的应用进行了讨论。已经研究了直径小至20 nm的铁电填充孔。
Phonon Hall effect with first-principles calculations
声子霍尔效应（Phonon Hall effect，PHE）近年来引起了人们的广泛关注，发表了许多理论和实验研究成果。虽然实验是在复杂的材料上进行的，但理论研究仍然徘徊在基于现象的模型上。此外，以前的微观理论被发现无法解释由钛酸锶（STO）实验获得的大的霍尔热导率。因此，作为第一次尝试，以弥补这一差距，我们实施第一性原理计算，以探索在实际材料中的PHE。我们的工作提供了一个新的基准的PHE在氯化钠（NaCl）在一个大的外部磁场。此外，我们证明了我们的结果在钛酸钡（BTO），并详细讨论了STO的结果与实验的偏差。作为一个可能的未来方向，我们进一步提出，内电子Berry曲率在STO PHE中起着重要的作用。
Imaging of Microwave Permittivity, Tunability, and Damage Recovery in (Ba,Sr)TiO3 Thin Films
我们描述了使用近场扫描微波显微镜定量成像的介电常数和1微米的长度尺度上的薄膜电介质样品的可调谐性。我们证明了这种技术的介电常数图像和局部磁滞回线的370 nm厚的钛酸锶钡薄膜在7.2 GHz。我们还观察到退火的作用，在恢复的介电可调谐性在受损区域的薄膜。我们可以在500下测量小至2的相对介电常数变化，以及小至0.03 V $^{-1}$的介电可调谐性变化。
