Article
Chemistry, Physical
Lanxia Hao, Yali Yang, Yu Huan, Hongbo Cheng, Yu-Yao Zhao, Yingying Wang, Jing Yan, Wei Ren, Jun Ouyang
Summary: By utilizing a modified Landau-Devonshire thermodynamic potential, the dielectric tunability of tetragonal ferroelectric films was analytically solved, predicting a high tunability of 80%. This predicted performance was successfully validated through density functional theory calculations, with epitaxial films showing favorable properties in experimental measurements.
NPJ COMPUTATIONAL MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Xianlong Cheng, Chao Zhou, Baichen Lin, Zhenni Yang, Shanquan Chen, Kelvin H. L. Zhang, Zuhuang Chen
Summary: Fluorite-structured Hf0.5Zr0.5O2 (HZO) thin films have gained attention for their good CMOS-compatibility and robust ferroelectricity. However, the challenges of high leakage current and poor endurance hinder the application of HZO in microelectronic devices. This study investigates the electric properties of Pt/HZO/La0.7Sr0.3MnO3 (LSMO) heterostructures and finds that the leakage mechanism is dominated by Schottky emission. By post-annealing in oxygen atmosphere, the barrier height can be increased, effectively reducing leakage current and improving endurance.
APPLIED MATERIALS TODAY
(2023)
Article
Chemistry, Physical
Hanfei Zhu, Guoqiang Feng, Xiaolong Chen, Xiao Lang, Huali Liu, Jun Ouyang
Summary: In this study, Sol-gel-derived (100)-textured Pb0.8La0.1Ca0.1Ti0.75O3 (PLCT) thin films were prepared at 450 degrees C with annealing in different atmospheres. The films annealed in O-2 showed improved electrical properties and energy storage capacity, along with distinct leakage current characteristics. The results suggest great potential for high-performance dielectric capacitors with high energy density and efficiency.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Engineering, Electrical & Electronic
Xinyan Wang, Can Wang, Xiaokang Yao, Yong Zhou, Ning Liang, Qiao Jin, Kun Chen, Meng He, Erjia Guo, Chen Ge, Guozhen Yang, Kuijuan Jin
Summary: In this study, Zn-doped BiFeO3 thin films were successfully grown on SrRuO3-buffered SrTiO3 substrates by pulsed laser deposition. The high-concentration Zn doping did not suppress the ferroelectric polarization of the films, while reducing leakage current and enhancing the photovoltaic effect. Optical and photoelectron spectroscopy measurements revealed that Zn doping increased oxygen vacancies and induced a structural evolution in the thin films, resulting in a blue-shift of the optical bandgap and an increase in the work function. The reduction of leakage current and the enhancement of photovoltaic effect were attributed to the variation of interfacial Schottky junctions and oxygen vacancies with doping. This study provides systematic insights into the effects of Zn doping on the physical properties of BiFeO3 thin films.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Physical
Hyun Wook Shin, Jong Yeog Son
Summary: Polycrystalline BiFeO3 (BFO) thin films with mixed c-oriented and a-oriented crystallinity were deposited on a (200) Pt/TiO2/SiO2/Si substrate. The presence of a-domains increased with the thickness of the films. The domain wall currents at the a-domain and c-domain boundaries of the BFO thin films were larger than those at the c-domain boundaries. The formation of a-domains significantly affected the leakage currents, ferroelectric polarizations, and piezoelectric coefficients of the BFO thin films.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Physics, Multidisciplinary
Zhongzhe Liu, Libin Gao, Kexin Liang, Zhen Fang, Hongwei Chen, Jihua Zhang
Summary: The study found that Bi1.5MgNb1.5O7 ceramic samples prepared by solid state reaction exhibit good crystalline structure, while BMN thin films fabricated using deposition method show high dielectric tunability under bias voltage. Raman analysis reveals that O'-A-O' and O-A-O bending modes significantly contribute to the dielectric constant.
Article
Engineering, Electrical & Electronic
Wei-Kai Wang, Kuo-Feng Liu, Sung-Yu Wang, Jian-Cheng Guo, Shih-Yung Huang
Summary: In this study, ZnGa2O4 films were deposited with different nitrogen impurity concentrations and post-annealed at different temperatures in NH3 atmosphere. The nitrogen-doping led to a decrease in optical band gap and structural changes, while secondary ion mass spectrometry analysis showed uniform distribution of nitrogen atoms in the film. The narrowing of the optical band gap was attributed to the hybridization of Zn3d and N2p orbits, promoting p-d repulsion in the valence band and forming a hexagonal wurtzite phase.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2021)
Article
Chemistry, Physical
Fang Wang, Cong Zhu, Shifeng Zhao
Summary: Lead-free perovskite-structured Na0.5Bi0.5TiO3 (NBT) thin films prepared by sol-gel technology exhibit good energy storage performance, with a recoverable energy density of 23.3 J/cm(3) and energy storage efficiency of 61.6%, making them promising for capacitors with high energy storage properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Ahmed M. El-Mahalawy, S. A. Mansour, Ahmed R. Wassel, Asmaa E. Mohamed, Shehab E. Ali
Summary: The study investigated the influence of substrate temperature on the properties of tin diselenide films, achieving the optimal growth conditions and fabricating isotype and anisotype junctions. Optical and electrical properties were estimated, leading to excellent optoelectronic performance.
SURFACES AND INTERFACES
(2022)
Article
Chemistry, Physical
Siyue Wei, Laijun Liu, Chen Xue, Yingzhi Meng, Yuzhou Luo, Feifei Han, Qi Zhang, Biaolin Peng
Summary: This study improves the performance of dielectric tunability in perovskite oxide thin films through two strategies, resulting in high dielectric tunability and excellent thermal stability. The findings demonstrate the potential application of middle entropy PSINT thin films in modern tunable devices.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Ceramics
Shihui Yu, Chunmei Zhang, Muying Wu, Helei Dong, Zheng Sun, Lingxia Li
Summary: The lead-free BMN1.5-BMN2 thin film, deposited by RF magnetron sputtering, exhibits very low loss tangent and high dielectric constant. It also shows superior energy storage properties with slim P-E loops, large maximum polarization, high charge storage density, high energy storage density, and energy conversion efficiency. Moreover, it provides new ideas for the design of lead-free linear dielectrics with ultrahigh energy storage density, making it a promising candidate for electrostatic energy storage capacitors.
CERAMICS INTERNATIONAL
(2021)
Article
Chemistry, Physical
Hongyan Xu, Mohammad Karbalaei Akbari, Siyan Wang, Shuhang Chen, Eugene Kats, Francis Verpoort, Jie Hu, Serge Zhuiykov
Summary: Thin MoO3 films were fabricated using atomic layer deposition technique, and their crystalline phase stabilization and oxygen vacancies enhancement were observed after annealing. The films exhibited memristive and opto-synaptic functionalities under infrared light illumination, which could simplify circuits in advanced opto-electronic systems and neuro-optoelectronic instruments.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Inorganic & Nuclear
Liuxue Xu, Shuanghao Wu, Kun Zhu, Baijie Song, Xiaofeng Zhou, Hao Yan, Bo Shen, Jiwei Zhai
Summary: The lead-free thin films BNT-xSBT deposited on Pt/Ti/SiO2/Si substrates by the sol-gel method exhibit excellent piezoelectric properties and flexible dielectric tunability. Mn doping in appropriate amounts significantly reduces leakage current in the films, resulting in an ultra-high inverse piezoelectric coefficient.
INORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Materials Science, Multidisciplinary
Shashi Priya Balmuchu, Somnath Sahu, Pamu Dobbidi
Summary: Highly crystalline and pure phase Bi0.993La0.007FeO3 (BLFO) thin films were successfully grown using pulsed laser deposition. The thin film exhibited a rhombohedral crystal structure with an R3c space group. Analysis confirmed the presence of BLFO phase and composition. X-ray photon spectroscopy revealed the presence of Fe in Fe3+ and Fe2+ states. The film showed high dielectric permittivity and low dielectric loss at room temperature, as well as enhanced magnetization and low leakage current density.
Article
Materials Science, Ceramics
J. Pundareekam Goud, Ajeet Kumar, Mahmoud S. Alkathy, Kongbrailatpam Sandeep, Akhil T. S. Raman, Bibhudatta Sahoo, Jungho Ryu, K. C. James Raju
Summary: Ba0.5Sr0.5TiO3 (BST) thin films with different thicknesses were fabricated on fused silica quartz substrate using pulsed laser deposition (PLD) technique. The thickness of thin films was changed by varying the number of pulses from 2500 to 20,000. X-ray diffraction (XRD) and Raman spectrum were used for phase confirmation, and field emission scanning electron microscopy (FESEM) was used to observe microstructure of BST thin films. The highest microwave tunability of 55.5% was achieved for the BST thin film with a thickness of 300 nm. It was found that too small film thicknesses and too thick films were not suitable for high dielectric tunability due to constraints by the amorphous substrate and approaching bulk grain size, respectively.
CERAMICS INTERNATIONAL
(2023)