scholarly journals Cation Vacancy in Wide Bandgap III‐Nitrides as Single‐Photon Emitter: A First‐Principles Investigation

2021 ◽  
pp. 2100100
Author(s):  
Hang Zang ◽  
Xiaojuan Sun ◽  
Ke Jiang ◽  
Yang Chen ◽  
Shanli Zhang ◽  
...  
2021 ◽  
Vol 125 (6) ◽  
pp. 1325-1335 ◽  
Author(s):  
Cesar Jara ◽  
Tomáš Rauch ◽  
Silvana Botti ◽  
Miguel A. L. Marques ◽  
Ariel Norambuena ◽  
...  

Author(s):  
Takahiro Kawamura ◽  
Toru Akiyama

Abstract Ga2O3 is a wide bandgap semiconductor and an understanding of its bandgap tunability is required to broaden the potential range of Ga2O3 applications. In this study, the different bandgaps of α-Ga2O3 were calculated by performing first-principles calculations using the pseudopotential self-interaction correction method. The relationships between these bandgaps and the material's hydrostatic, uniaxial, and equibiaxial lattice strains were investigated. The direct and indirect bandgaps of strain-free α-Ga2O3 were 4.89 eV and 4.68 eV, respectively. These bandgap values changed linearly and negatively as a function of the hydrostatic strain. Under the uniaxial and equibiaxial strain conditions, the maximum bandgap appeared under application of a small compressive strain, and the bandgaps decreased symmetrically with increasing compressive and tensile strain around the maximum value.


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2972
Author(s):  
Masaya Ichimura

Magnesium hydroxide (Mg(OH)2) has a wide bandgap of about 5.7 eV and is usually considered an insulator. In this study, the energy levels of impurities introduced into Mg(OH)2 are predicted by first-principles calculations. A supercell of brucite Mg(OH)2 consisting of 135 atoms is used for the calculations, and an impurity atom is introduced either at the substitutional site replacing Mg or the interlayer site. The characteristics of impurity levels are predicted from density-of-states analysis for the charge-neutral cell. According to the results, possible shallow donors are trivalent cations at the substitutional site (e.g., Al and Fe) and cation atoms at the interlayer site (Cu, Ag, Na, and K). On the other hand, an interlayer F atom can be a shallow acceptor. Thus, valence control by impurity doping can turn Mg(OH)2 into a wide-gap semiconductor useful for electronics applications.


2018 ◽  
Vol 9 ◽  
pp. 1085-1094 ◽  
Author(s):  
Kelvin Chung ◽  
Yu H Leung ◽  
Chap H To ◽  
Aleksandra B Djurišić ◽  
Snjezana Tomljenovic-Hanic

Fluorescence properties of crystallographic point defects within different morphologies of titanium dioxide were investigated. For the first time, room-temperature single-photon emission in titanium dioxide optical defects was discovered in thin films and commercial nanoparticles. Three-level defects were identified because the g (2) correlation data featured prominent shoulders around the antibunching dip. Stable and blinking photodynamics were observed for the single-photon emitters. These results reveal a new room-temperature single-photon source within a wide bandgap semiconductor.


2020 ◽  
Vol 34 (06) ◽  
pp. 2050034
Author(s):  
Congcong Zeng ◽  
Ru Zhang ◽  
Liyuan Wu ◽  
Qian Wang ◽  
Xi Chen ◽  
...  

[Formula: see text], a semiconductor with wide bandgap, has attracted wide attention due to its excellent workability in the short-wave region. Here, we reported the mechanical, electronic and optical properties of bulk and monolayer [Formula: see text] by using first-principles calculations. Our results show that both Young’s modulus and Poisson’s ratio of the monolayer [Formula: see text] exhibit anisotropic behaviors. From the bulk to the monolayer structure, the direct bandgap increases from 2.496 eV to 3.030 eV. Compared to the bulk structure, the monolayer [Formula: see text] exhibits the small average effective mass and significant anisotropy in optical absorption, indicating potential optoelectronic applications.


PhotoniX ◽  
2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Lemin Jia ◽  
Wei Zheng ◽  
Feng Huang

Abstract High-performance vacuum-ultraviolet (VUV) photodetectors are of great significance to space science, radiation monitoring, electronic industry and basic science. Due to the absolute advantages in VUV selective response and radiation resistance, ultra-wide bandgap semiconductors such as diamond, BN and AlN attract wide interest from researchers, and thus the researches on VUV photodetectors based on these emerging semiconductor materials have made considerable progress in the past 20 years. This paper takes ultra-wide bandgap semiconductor filterless VUV photodetectors with different working mechanisms as the object and gives a systematic review in the aspects of figures of merit, performance evaluation methods and research progress. These miniaturized and easily-integrated photodetectors with low power consumption are expected to achieve efficient VUV dynamic imaging and single photon detection in the future.


AIP Advances ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 105202 ◽  
Author(s):  
Xin Tan ◽  
Tiebang Liu ◽  
Xuejie Liu ◽  
Yuan Ren ◽  
Shiyang Sun ◽  
...  

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