Intersubband Transitions in Nonpolar GaN-based Resonant Phonon Depopulation Multiple-Quantum Wells for Terahertz Emissions
Ya-Feng Song1, Xiong-Xiong Kong1, Wei-Bin Tang1, Zhong-Qiang Suo1, Huan Zhang1, Chen-Yang Li1, Qian Jia1, Cai-Xia Xue1, Yan-Wu Lu2, Chao-Pu Yang3
1Department of Physics, College of Electronic Information and Electrical Engineering, Shangluo University, Shangzhou 726000, China
2Department of Physics, Beijing Jiaotong University, Beijing 100044, China
3College of Chemical Engineering and Modern Materials, Shangluo University, Shangzhou 726000, China
We investigate the polarization effect in intersubband transitions in polar and nonpolar GaN-based multiple-quantum well (MQW) quantum cascade (QC) structures for terahertz (THz) emissions by comparisons, and design a nonpolar GaN/Al$_{0.2}$Ga$_{0.8}$N QC structure of 7.27 THz emissions which matches the resonant phonon depopulation condition (92.7 meV) for better population inversion. It shows a lower threshold current density Jth and a higher output power at all temperatures. We also find that the Jth of the nonpolar GaN MQW QC structures increases more slowly than that of the polar ones of the same structrure as temperature increases.
J. Korean Phys. Soc. 2019; 74: 1039-1045  https://doi.org/10.3938/jkps.74.1039
Influence of Bi Excess on the Structural and Morphological Properties of Bi$_{0.5}$K$_{0.5}$TiO$_3$ Synthesized by Using the Hydrothermal Method and Its Nanogenerator Properties
Seon Yong Kim1, Eun Young Kim1, Sang Don Bu1, Jin Kyu Han2, Da Som Song2, Jongsun Lim2, Ki-Seok An2
1Department of Physics and Research Institute of Physics and Chemistry, Chonbuk National University, Jeonju 54896, Korea
2Thin Film Materials Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Korea
We investigated the effects of an excess of bismuth in Bi$_{0.5}$K$_{0.5}$TiO$_3$ (BKT) on its structural and morphological properties. Two types of BKT samples were prepared using bismuth stoichiometry, where one with a Bi:K molar ratio of 1:1 (S-BKT) and the other with a ratio of 1.1:1 with 10 mol% excess of Bi (10% BKT). These samples were prepared using the hydrothermal synthesis method. When the X-ray diffraction (XRD) data for the two samples were compared, the 10% BKT shows a 1.3 times larger than that for the S-BKT sample in the ratio of the secondary phase peak to the BKT (101) peak at approximately 29.3$^\circ$. Morphology analysis showed that both samples had agglomerations with diameters of approximately 200 nm and nanowires with lengths of 1–2 $\mu$m and diameters of 8 nm. The fractions of the total area occupied by agglomerations in the two samples were estimated at approximately 95% for 10% BKT and approximately 45% for S-BKT. These results indicate that an excess of bismuth affects the secondary phase and agglomeration formation. Nanogenerators were prepared by mixing S-BKT, and their output voltages were 1.8 V and their outputs currents were 4 nA.
J. Korean Phys. Soc. 2019; 74: 1027-1031  https://doi.org/10.3938/jkps.74.1027
Most Cited
Cited by
Variations in the Raman Spectrum as a Function of the Number \ofGraphene Layers
J. Korean Phy. Soc. 2009; 55: 1299~1303  https://doi.org/10.3938/jkps.55.1299
Full Text(PDF) [download: 0]
A Gravity Dual of RHIC Collisions
J. Korean Phy. Soc. 2007; 50: 384~397  https://doi.org/10.3938/jkps.50.384
Full Text(PDF) [download: 0]
X-ray Diffraction Patterns of Thermally-reduced Graphenes
J. Korean Phy. Soc. 2010; 57: 1649~1652  https://doi.org/10.3938/jkps.57.1649
Full Text(PDF) [download: 0]
A New Phase at a Finite Quark Density from AdS/CFT
J. Korean Phy. Soc. 2008; 52: 1734~1739  https://doi.org/10.3938/jkps.52.1734
Full Text(PDF) [download: 0]
Al-ZnO Thin Films as Transparent Conductive Oxides : Synthesis, Characterization, and Application Tests
J. Korean Phy. Soc. 2007; 50: 622~625  https://doi.org/10.3938/jkps.50.622
Full Text(PDF) [download: 0]
The Updated Vversion of Chinese Evaluated Nuclear Data Library (CENDL-3.1)
J. Korean Phy. Soc. 2011; 59: 1052~1056  https://doi.org/10.3938/jkps.59.1052
Full Text(PDF) [download: 0]
Annealing Effect on the Electrical and the Optical Characteristics of Undoped ZnO Thin Films Grown on Si Substrates by RF Magnetron Sputtering
J. Korean Phy. Soc. 2007; 51: 1378~1382  https://doi.org/10.3938/jkps.51.1378
Full Text(PDF) [download: 0]
An Explanation of Efficiency Droop in InGaN-based Light Emitting Diodes: Saturated Radiative Recombination Rate at Randomly Distributed In-Rich Active Areas
J. Korean Phy. Soc. 2011; 58: 503~508  https://doi.org/10.3938/jkps.58.503
Full Text(PDF) [download: 0]
Chitosan-Coated Ferrite (Fe3O4) Nanoparticles as a T2 Contrast Agent for Magnetic Resonance Imaging
J. Korean Phy. Soc. 2010; 56: 868~873  https://doi.org/10.3938/jkps.56.868
Full Text(PDF) [download: 0]
The Proton Energy Response of a LYSO Crystal
J. Korean Phy. Soc. 2008; 52: 925~929  https://doi.org/10.3938/jkps.52.925
Full Text(PDF) [download: 0]
Effect of Oxygen on the Optical and the Electrical Properties of Amorphous InGaZnO Thin Films Prepared by RF Magnetron Sputtering
J. Korean Phy. Soc. 2008; 53: 2019~2023  https://doi.org/10.3938/jkps.53.2019
Full Text(PDF) [download: 0]
Results from the IAEA Benchmark of Spallation Models
J. Korean Phy. Soc. 2011; 59: 791~796  https://doi.org/10.3938/jkps.59.791
Full Text(PDF) [download: 0]
The effect of thermal and ultrasonic treatment on formation of graphene oxide nanosheets
J. Korean Phy. Soc. 2010; 56: 1097~1102  https://doi.org/10.3938/jkps.56.1097
Full Text(PDF) [download: 0]
First-Principles Study of the Surface of Wurtzite ZnO and ZnS - Implications for Nanostructure Formation
J. Korean Phy. Soc. 2009; 54: 867~872  https://doi.org/10.3938/jkps.54.867
Full Text(PDF) [download: 0]
Synthesis of Zinc Ferrite and Its Photocatalytic Application under Visible Light
J. Korean Phy. Soc. 2009; 54: 204~208  https://doi.org/10.3938/jkps.54.204
Full Text(PDF) [download: 0]
Status of the JEFF Nuclear Data Library
J. Korean Phy. Soc. 2011; 59: 1057~1062  https://doi.org/10.3938/jkps.59.1057
Full Text(PDF) [download: 0]
Photocatalytic Hydrogen Generation from Water-methanol MixturesUsing Nanocrystalline ZnFe$_2$O$_4$ under Visible Light Irradiation
J. Korean Phy. Soc. 2009; 55: 1472~1477  https://doi.org/10.3938/jkps.55.1472
Full Text(PDF) [download: 0]
Properties of TiO2 Films Prepared for Use in Dye-sensitized Solar Cells by Using the Sol-gel Method at Different Catalyst Concentrations
J. Korean Phy. Soc. 2010; 57: 1049~1053  https://doi.org/10.3938/jkps.57.1049
Full Text(PDF) [download: 0]
  Comparison between SiOC Thin Film by plasma enhance chemical vapor deposition and SiO2 Thin Film by Fourier Transform Infrared Spectroscopy  
J. Korean Phy. Soc. 2010; 56: 1150~1155  https://doi.org/10.3938/jkps.56.1150
Full Text(PDF) [download: 0]
Atomic Layer Deposition of Ruthenium and Ruthenium-oxide ThinFilms by Using a Ru(EtCp)$_{2}$ Precursor and Oxygen Gas
J. Korean Phy. Soc. 2009; 55: 32~37  https://doi.org/10.3938/jkps.55.32
Full Text(PDF) [download: 0]
Go to page for Current Issue
Go to page for Current Issue
  • e-Submission
  • For review & Editor

Indexed/Covered by

  • Scopus