Temperature dependence of the band gap of high optical quality CdS:Dy thin films based on exciton spectra

2018 ◽  
Vol 5 (12) ◽  
pp. 125902 ◽  
Author(s):  
Yu P Gnatenko ◽  
P M Bukivskij ◽  
M S Furier ◽  
A P Bukivskii ◽  
A S Opanasyuk
2018 ◽  
Vol 197 ◽  
pp. 343-348 ◽  
Author(s):  
Yu.S. Yeromenko ◽  
Yu.P. Gnatenko ◽  
A.S. Opanasyuk ◽  
D.I. Kurbatov ◽  
P.M. Bukivskij ◽  
...  

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4326 ◽  
Author(s):  
Andrea Chiappini ◽  
Laura Pasquardini ◽  
Somayeh Nodehi ◽  
Cristina Armellini ◽  
Nicola Bazzanella ◽  
...  

In this paper, we described a versatile two steps approach for the realization of silica inverse opals functionalized with DNA-aptamers labelled with Cy3 fluorophore. The co-assembly method was successfully employed for the realization of high quality inverse silica opal, whilst the inverse network was functionalized via epoxy chemistry. Morphological and optical assessment revealed the presence of large ordered domains with a transmission band gap depth of 32%, after the functionalization procedure. Finite Difference Time-Domain (FDTD) simulations confirmed the high optical quality of the inverse opal realized. Photoluminescence measurements evidenced the effective immobilization of DNA-aptamer molecules labelled with Cy3 throughout the entire sample thickness. This assumption was verified by the inhibition of the fluorescence of Cy3 fluorophore tailoring the position of the photonic band gap of the inverse opal. The modification of the fluorescence could be justified by a variation in the density of states (DOS) calculated by the Plane Wave Expansion (PWE) method. Finally, the development of the aforementioned approach could be seen as proof of the concept experiment, suggesting that this type of system may act as a suitable platform for the realization of fluorescence-based bio-sensors.


2018 ◽  
Vol 63 (1) ◽  
pp. 33 ◽  
Author(s):  
O. G. Trubaieva ◽  
A. I. Lalayants ◽  
M. A. Chaika

ZnSxSe1−x bulk crystals were grown by the Bridgman–Stockbarger method. The transmittance of different samples in the range from 67% to 56% at la = 1100 nm (for 4-mm samples) indicates a high optical quality of the crystals. No new states were revealed at the sulfur incorporation, and the band gap depends on the composition. The optical band gap of ZnSxSe1−x bulk crystals varies from 2.59 to 2.78 eV for direct transitions and from 2.49 to 2.70 eV for indirect transitions.


2006 ◽  
Vol 6 (1) ◽  
pp. 103-108 ◽  
Author(s):  
K. Ramamoorthy ◽  
C. Sanjeeviraja ◽  
M. Jayachandran ◽  
K. Sankaranarayanan ◽  
Pankaj Misra ◽  
...  

1998 ◽  
Author(s):  
D. Ghica ◽  
Mariuca Gartner ◽  
F. Ciobanu ◽  
V. Nelea ◽  
C. Martin ◽  
...  

2013 ◽  
Vol 11 (7) ◽  
pp. 1163-1171
Author(s):  
Judita Šukytė ◽  
Remigijus Ivanauskas

AbstractThe preparative conditions were optimized to get chalcogens layers on the polymer — polyamide PA surface by sorption at room temperature using sodium telluropentathionate, Na2TeS4O6. Further interaction of chalcogenized dielectric with copper’s (I/II) salt solution leads to the formation of mixed CuxSy-CuxTey layers. Optical, electrical and surface characteristics of the layers are highly controlled by the deposition parameters. The stoichiometry of these layers was established by UV-Visible and AA spectrometry. Optical absorption (transmittance) experiments show the samples are of high optical quality. The band gaps of thin films were obtained from their optical absorption spectra, which were found in the range of 1.44–2.97 eV. XRD was used in combination with AFM to characterize chalcogenides layers’ structural features. XRD analysis confirmed the formation of mixed copper chalcogenides’ layers in the surface of PA with binary phases such as Cu2Te, Cu3.18Te2, copper telluride, Cu2.72Te2, vulcanite, CuTe, anilite, Cu7S4 and copper sulfide, Cu1.8S. The crystallite sizes of thin films calculated by the Scherer formula were found to be in the range of 3.07–13.53 nm for CuxSy crystallites and 4.06–20.79 nm for CuxTey crystallites. At room temperature an electrical resistance of CuxSy-CuxTey layers varies from 3.0×103 kΩ□−1 to 1.0 kΩ□−1.


1992 ◽  
Vol 271 ◽  
Author(s):  
Mark A. Harmer ◽  
Mark G. Roelofs

ABSTRACTIn this paper we describe a novel route for the formation of thin films of potassium titanyl phosphate (KTiOPO4 KTP) via a sol-gel route. The ability to form films of high optical quality depends upon the precursor chemistry developed. Formation of stoichiometric films is especially challenging in three component systems and a number of precursors have been investigated. The basic chemistry, processing and resulting microstructure will be described. Transparent, dense and continuous films have been prepared with grain sizes typically of 0.3μm or less depending upon the processing conditions. Some textured growth patterns are observed although the films are essentially polycrystalline. Using the prism coupling technique the films have been found to exhibit waveguiding.


2010 ◽  
Vol 20 (36) ◽  
pp. 7676 ◽  
Author(s):  
Aude Demessence ◽  
Cédric Boissière ◽  
David Grosso ◽  
Patricia Horcajada ◽  
Christian Serre ◽  
...  

2012 ◽  
Vol 111 (7) ◽  
pp. 073511 ◽  
Author(s):  
R. C. Rai ◽  
M. Guminiak ◽  
S. Wilser ◽  
B. Cai ◽  
M. L. Nakarmi

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