Optical Properties of Alq3/TiO2 BDR Structure Processed by Spin Coating Technique

MRS Advances ◽  
2019 ◽  
Vol 4 (11-12) ◽  
pp. 661-666
Author(s):  
L. Ajith DeSilva ◽  
Sarahn Nazaret ◽  
A. G. U. Perera ◽  
T. M. W. J. Bandara
Keyword(s):  
Thin Films ◽  
Titanium Dioxide ◽  
Optical Properties ◽  
Band Gap ◽  
Spin Coating ◽  
Light Emission ◽  
Wide Band ◽  
Bragg Reflector ◽  
Distributed Bragg Reflector ◽  
Pl Quenching

ABSTRACTOne-dimensional hybrid Distributed Bragg Reflector (DBR) is constructed using Tris (8-hydroxy) quinoline aluminum (Alq3) molecules and Titanium dioxide (TiO2) nanoparticles via spin coating process. Light emission from thin films of low molecular weight organic semiconductor of Alq3 is dominated by excitons. This material has been widely used as a superior emitter for organic light emitting diodes. Titanium dioxide (TiO2) is an inorganic semiconductor with a high band gap. Photoluminescence (PL) of thin films of Alq3 showed a broad PL peak at 530 nm. In DBR structures, PL quenching is observed but there is no shift in the PL peak of the Alq3. The PL quenching is tentatively attributed to energy transfer via sensitization to wide band gap TiO2 layers. A simple excitonic model is suggested to explain the observation. Fabrication process and optical properties of the structure are presented.

scholarly journals Optical Properties of Wide Band Gap Indium Sulphide Thin Films Obtained by Physical Vapor Deposition

2001 ◽  
Vol 184 (1) ◽  
pp. 179-186 ◽  
Author(s):  
N. Barreau ◽  
S. Marsillac ◽  
J.C. Bern�de ◽  
T. Ben Nasrallah ◽  
S. Belgacem
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Wide Band ◽  
Wide Band Gap ◽  
Indium Sulphide

Morphological and Optical Properties of Different Mg Percentage of ZnO/Mg Thin Films Prepared by Sol-Gel Spin-Coating and Immersion Method

2015 ◽  
Vol 1107 ◽  
pp. 637-642 ◽  
Author(s):  
Aadila Aziz ◽  
R. Mohamed ◽  
A.N. Afaah ◽  
N.A.M. Asib ◽  
M. Rusop ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Spin Coating ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Immersion Method ◽  
Weight Percentage ◽  
Tauc Plot ◽  
Vis Spectroscopy

We have successfully demonstrated ZnO/Mg thin films on Mg seeded-template by using sol-gel spin-coating and immersion technique. By increasing weight percentage of Mg, zinc particles become agglomerate and displayed flower formed as displayed in FESEM characterization. It was observed that the morphology of the zinc particles on Mg seeded-template change from inconsistently distribution for 1 and 3 % into cluster flower-like of zinc particles for 5 and 7 % weight percentage of Mg. The optical properties of the ZnO/Mg thin films were examined by UV-Vis spectroscopy and the Tauc plot methods was used to estimate the optical band gap. The study reveals that, 7 % weight percentage of Mg was recorded as the highest transmittance which is more than 60 % in visible wavelength compared to others. With the rise weight percentage of Mg, the transmittance of the thin films was increased except for 5 %. This gradually downgraded to below 60 % of transmission most probably due to the grain size that becomes bigger. The optical band gap can be tuned by using different Mg percentage to the ZnO/Mg thin films.

scholarly journals The Effect of the Deposition Method on the Structural and Optical Properties of ZnS Thin Films

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1064
Author(s):  
Iosif-Daniel Simandan ◽  
Florinel Sava ◽  
Angel-Theodor Buruiana ◽  
Ion Burducea ◽  
Nicu Becherescu ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Rutherford Backscattering Spectrometry ◽  
Wide Band ◽  
Deposition Method ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Wide Band Gap ◽  
X Ray

ZnS is a wide band gap material which was proposed as a possible candidate to replace CdS as a buffer layer in solar cells. However, the structural and optical properties are influenced by the deposition method. ZnS thin films were prepared using magnetron sputtering (MS), pulsed laser deposition (PLD), and a combined deposition technique that uses the same bulk target for sputtering and PLD at the same time, named MSPLD. The compositional, structural, and optical properties of the as-deposited and annealed films were inferred from Rutherford backscattering spectrometry, X-ray diffraction, X-ray reflectometry, Raman spectroscopy, and spectroscopic ellipsometry. PLD leads to the best stoichiometric transfer from target to substrate, MS makes fully amorphous films, whereas MSPLD facilitates obtaining the densest films. The study reveals that the band gap is only slightly influenced by the deposition method, or by annealing, which is encouraging for photovoltaic applications. However, sulphur vacancies contribute to lowering the bandgap and therefore should be controlled. Moreover, the results add valuable information towards the understanding of ZnS polymorphism. The combined MSPLD method offers several advantages such as an increased deposition rate and the possibility to tune the optical properties of the obtained thin films.

STRUCTURAL, OPTICAL PROPERTIES AND PHOTOCATALYTIC ACTIVITY OF NANOCRYSTALLINE TiO2 THIN FILMS DEPOSITED BY SOL-GEL SPIN COATING

2019 ◽  
Vol 7 (1) ◽  
pp. 28
Author(s):  
KOMARAIAH DURGAM ◽  
RADHA EPPA ◽  
REDDY M. V. RAMANA ◽  
KUMAR J. SIVA ◽  
R. SAYANNA ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Photocatalytic Activity ◽  
Spin Coating ◽  
Sol Gel ◽  
Tio2 Thin Films ◽  
Nanocrystalline Tio2

Wide Band-Gap Kesterite Thin Films for Photovoltaic Applications

2018 ◽  
Author(s):  
Raquel Caballero ◽  
Leonor de la Cueva ◽  
Andrea Ruiz-Perona ◽  
Yudenia Sánchez ◽  
Markus Neuschitzer ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Wide Band ◽  
Wide Band Gap ◽  
Photovoltaic Applications

Sol-gel growth of Ni doped CdS on glass substrates: effect of spin coating speed and dopant concentration

2020 ◽  
Vol 10 ◽  
Author(s):  
Atefeh Nazari Setayesh ◽  
Hassan Sedghi
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spin Coating ◽  
Optical Band Gap ◽  
Dopant Concentration ◽  
Rotation Speed ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Glass Substrates

Background: In this work, CdS thin films were synthesized by sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, 5 wt.%) were investigated. The optical properties of thin films such as refraction index, extinction coefficient, dielectric constant and optical band gap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration has influenced the optical properties of thin films. By decreasing rotation speed of the substrate which results in films with more thicknesses, more optical interferences were appeared in the results. Conclusion: The samples doped with Ni comparing to pure ones have had more optical band gap energy.

Deposition time dependent study of structural and optical properties of PbS thin films grown by CBD method

2020 ◽  
Vol 13 ◽  
Author(s):  
Minakshi Chaudhary ◽  
Yogesh Hase ◽  
Ashwini Punde ◽  
Pratibha Shinde ◽  
Ashish Waghmare ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Deposition Time ◽  
Secondary Growth ◽  
Cost Effective ◽  
Xrd Analysis ◽  
Structural Morphology ◽  
Glass Substrates ◽  
Cbd Method

: Thin films of PbS were prepared onto glass substrates by using a simple and cost effective CBD method. Influence of deposition time on structural, morphology and optical properties have been investigated systematically. The XRD analysis revealed that PbS films are polycrystalline with preferred orientation in (200) direction. Enhancement in crystallinity and PbS crystallite size has been observed with increase in deposition time. Formation of single phase PbS thin films has been further confirmed by Raman spectroscopy. The surface morphology analysis revealed the formation of prismatic and pebble-like PbS particles and with increase in deposition time these PbS particles are separated from each other without secondary growth. The data obtained from the EDX spectra shows the formation of high-quality but slightly sulfur rich PbS thin films over the entire range of deposition time studied. All films show increase in absorption with increase in deposition time and a strong absorption in the visible and sub-band gap regime of NIR range of the spectrum with red shift in band edge. The optical band gap shows decreasing trend, as deposition time increases but it is higher than the band gap of bulk PbS.

Stretching-Driven Crystal Anisotropy and Optical Modulations of Flexible Wide Band Gap Inorganic Thin Films

2019 ◽  
Vol 11 (44) ◽  
pp. 41516-41522
Author(s):  
Hong Je Choi ◽  
Woosun Jang ◽  
Young Eun Kim ◽  
Aloysius Soon ◽  
Yong Soo Cho
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Wide Band ◽  
Wide Band Gap ◽  
Crystal Anisotropy ◽  
Inorganic Thin Films
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