scholarly journals Polarization-dependent excitons and plasmon activity in nodal-line semimetal ZrSiS

Author(s):  
Juan J. Meléndez ◽  
A. Cantarero

The optical properties of ZrSiS arise from intense excitonic activity, with different character and spatial extension depending on the polarization of the incident light. The system also exhibits plasmonic activity, while the plasmons are unstable and decay into electron–hole pairs.

1998 ◽  
Vol 536 ◽  
Author(s):  
H. Porteanu ◽  
A. Glozman ◽  
E. Lifshitz ◽  
A. Eychmüller ◽  
H. Weller

AbstractCdS/HgS/CdS nanoparticles consist of a CdS core, epitaxially covered by one or two monolayers of HgS and additional cladding layers of CdS. The present paper describes our efforts to identify the influence of CdS/HgS/CdS interfaces on the localization of the photogenerated carriers deduced from the magneto-optical properties of the materials. These were investigated by the utilization of optically detected magnetic resonance (ODMR) and double-beam photoluminescence spectroscopy. A photoluminescence (PL) spectrum of the studied material, consists of a dominant exciton located at the HgS layer, and additional non-excitonic band, presumably corresponding to the recombination of trapped carriers at the interface. The latter band can be attenuated using an additional red excitation. The ODMR measurements show the existence of two kinds of electron-hole recombination. These electron-hole pairs maybe trapped either at a twin packing of a CdS/HgS interface, or at an edge dislocation of an epitaxial HgS or a CdS cladding layer.


RSC Advances ◽  
2021 ◽  
Vol 11 (35) ◽  
pp. 21824-21831
Author(s):  
X. Q. Deng ◽  
R. Q. Sheng ◽  
Q. Jing

The CBM (VBM) of the heterostructure is mainly contributed by the BAs (arsenene), which will favor the separation of photogenerated electron–hole pairs.


2014 ◽  
Vol 924 ◽  
pp. 260-268 ◽  
Author(s):  
Hao Chen ◽  
Lan Fang Yao ◽  
Song Lin Yang ◽  
Ya Qin Wang ◽  
Xing Liang ◽  
...  

The crystal structures, band structures, density of states, charge density, overlap population and optical properties of pure anatase TiO2 and Pr-doped anatase TiO2 were studied by using the plane-wave pseudopotential method based on the first-principles. After Pr doping, the valence band and the conduction band moved down and became dense, energy gap became narrow and a impurity band which consists of Pr 4f states appeared. And the dipole moment got improved, which is good for the separate of the electron-hole pairs. These effectively overcome two huge shortcomings of TiO2. Besides, Pr-doped anatase TiO2 produced more carriers which have good transport properties and the absorption spectra of Pr-O bond appear in the region that the wavelength is longer. The calculation results of optical properties show that the absorption edge occured red shift, which means the photocatalytic activity of anatase TiO2 got remarkable improved during visible-light region. This conforms to the previous analysis. So the photocatalytic activity of anatase TiO2 got remarkable improved after Pr doping.


2012 ◽  
Vol 554-556 ◽  
pp. 502-506 ◽  
Author(s):  
Li Wei Wang ◽  
Terry A. Egerton

Chromium doped rutile TiO2was synthesized by either co-precipitation or impregnation (surface-doping) and characterized by XRD and reflectance spectroscopy. Chromium addition did not change the TiO2structure nor did the structure of the co-precipitated products differ from that of the impregnated samples. However, chromium doping moved the absorption of both sets of products into the visible and significantly affected the TiO2photocatalytic activity for isopropanol (IPA) oxidation. At high chromium concentrations the photoactivity of the co-precipitated samples was reduced by a larger amount than that of the impregnated samples; this was attributed to a higher concentration of Cr3+ions in the rutile lattice. Unexpectedly, increased photoactivity was measured for low Cr levels of surface-doped rutile. This may be caused by increased electron-trapping, at surface Cr6+ions, and correspondingly reduced, electron-hole recombination.


1993 ◽  
Vol 17 (2) ◽  
pp. 157-160
Author(s):  
N. Kawai ◽  
Z. Hirano ◽  
E. Komuro ◽  
T. Namikawa ◽  
Y. Yamazaki

2022 ◽  
Author(s):  
Atefeh Fazel Najafabadi ◽  
Baptiste Auguié

The optical properties of nanoparticle clusters vary with the spatial arrangement of the constituent particles, but also the overall orientation of the cluster with respect to the incident light. This...


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ryosuke Watanabe ◽  
Yohei Eguchi ◽  
Takuya Yamada ◽  
Yoji Saito

Antireflection coating (ARC) prepared by a wet process is beneficial for low cost fabrication of photovoltaic cells. In this study, we investigated optical properties and morphologies of spin-coated TiO2ARCs on alkaline textured single-crystalline silicon wafers. Reflectance spectra of the spin-coated ARCs on alkaline textured silicon wafers exhibit no interferences and low reflectance values in the entire visible range. We modeled the structures of the spin-coated films for ray tracing numerical calculation and compared numerically calculated reflectance spectra with the experimental results. This is the first report to clarify the novel optical properties experimentally and theoretically. Optical properties of the spin-coated ARCs without interference are due to the fractional nonuniformity of the thickness of the spin-coated ARCs that cancels out the interference of the incident light.


1974 ◽  
Vol 33 (13) ◽  
pp. 771-774 ◽  
Author(s):  
J. M. Worlock ◽  
T. C. Damen ◽  
K. L. Shaklee ◽  
J. P. Gordon

2019 ◽  
Vol 6 (1) ◽  
pp. 1900860 ◽  
Author(s):  
Weiqing Zhou ◽  
Alexander N. Rudenko ◽  
Shengjun Yuan

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