Nanostructured pyronin Y thin films as a new organic semiconductor: Linear/nonlinear optics, band gap and dielectric properties

2017 ◽  
Vol 513 ◽  
pp. 95-102 ◽  
Author(s):  
H.Y. Zahran ◽  
I.S. Yahia ◽  
F.H. Alamri
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Nonlinear Optics ◽  
Band Gap ◽  
Organic Semiconductor

Microstructure, dielectric properties and optical band gap control on the photoluminescence behavior of Ba[Zr0.25Ti0.75]O3 thin films

2008 ◽  
Vol 49 (1) ◽  
pp. 35-46 ◽  
Author(s):  
L. S. Cavalcante ◽  
J. C. Sczancoski ◽  
F. S. De Vicente ◽  
M. T. Frabbro ◽  
M. Siu Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Band Gap ◽  
Optical Band Gap ◽  
Gap Control ◽  
Photoluminescence Behavior

Preparation and Characterization of a Novel Organic Semiconductor Indacenedithiophene Derivative and the Corresponding Langmuir-Blodgett Thin Films

2019 ◽  
Vol 19 (11) ◽  
pp. 7244-7250 ◽  
Author(s):  
Violeta Alvarez-Venicio ◽  
Rafael O. Arcos-Ramos ◽  
José Alfonso Hernández-Rojas ◽  
Jaime Octavio Guerra-Pulido ◽  
Vladimir A. Basiuk ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Organic Semiconductor ◽  
Density Functional ◽  
Stokes Shift ◽  
Langmuir Monolayers ◽  
Emission Spectra ◽  
Morphological Properties ◽  
Homogeneous Distribution ◽  
Langmuir Blodgett

The synthesis of a novel indacenedithiophene derivative (IDT-DPA) is described, which exhibits semiconducting behavior. Its properties were measured by means of UV-visible and fluorescence spectroscopies using toluene as solvent. An extinction molar coefficient of 2.05×104 M−1 cm−1 and a Stokes shift of 50 nm were obtained. A theoretical study was performed using the density functional theory, from which HOMO–LUMO band gap of 1.711 eV was calculated. IDT-DPA was deposited on the water-air interface to form Langmuir monolayers. π-A curves and hysteresis were measured showing reversibility behavior. The monolayers were transferred to glass substrates as Langmuir-Blodgett thin films. Their morphological properties were characterized by using scanning electron and atomic force microscopy, which showed that the films tend to form clusters with a homogeneous distribution. Absorption and emission spectra of the films were measured, from which the optical band gap and Stocks shift were derived. Based on the electronic properties and light emission spectra of IDT-DPA, this compound can be proposed for the applications in organic lightemitting diodes and other organic semiconductor devices.

The Effects of the Annealing Conditions on the Dielectric Properties of the Sol-Gel Derived MgNb2O6 Thin Films

2014 ◽  
Vol 90 ◽  
pp. 7-11
Author(s):  
Yi Da Ho ◽  
Kung Rong Chen ◽  
Cheng Liang Huang
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Integrated Circuits ◽  
Band Gap ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Visible Range ◽  
Annealing Conditions ◽  
Ito Glass

MgNb2O6, a well-known ceramic material with columbite crystal structure, has attracted much attention in microwave integrated circuits and optical applications due to its superior properties, such as its high dielectric constant and an optical band gap. In this work, transparent amorphous-MgNb2O6thin films were fabricated on ITO/glass substrates using the sol-gel method. The average optical transmission percentage in the visible range (λ=400–800 nm) is over 80% for all MgNb2O6/ITO/glass samples, while the optical band gap is estimated at ~4 eV. On the other hand, the dielectric properties of the MgNb2O6thin films were very sensitive to the annealing conditions. In this study, the dielectric constant of the films was calculated to be higher than 30 under a 100 kHz AC electric field. The effects of the annealing temperature and atmosphere on the dielectric properties of the MgNb2O6thin films were investigated.

Stability Investigation in the Optical Properties of Thermally Evaporated Ge5Se95-x Znx Thin Films

2015 ◽  
Vol 7 (3) ◽  
pp. 1923-1930
Author(s):  
Austine Amukayia Mulama ◽  
Julius Mwakondo Mwabora ◽  
Andrew Odhiambo Oduor ◽  
Cosmas Mulwa Muiva ◽  
Boniface Muthoka ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Optical Band Gap ◽  
Thermal Evaporation ◽  
Optical Transition ◽  
Bulk Material ◽  
Band Gap Energy ◽  
Optical Absorbance ◽  
Gap Energy ◽  
Constituent Elements

 Selenium-based chalcogenides are useful in telecommunication devices like infrared optics and threshold switching devices. The investigated system of Ge5Se95-xZnx (0.0 ≤ x ≤ 4 at.%) has been prepared from high purity constituent elements. Thin films from the bulk material were deposited by vacuum thermal evaporation. Optical absorbance measurements have been performed on the as-deposited thin films using transmission spectra. The allowed optical transition was found to be indirect and the corresponding band gap energy determined. The variation of optical band gap energy with the average coordination number has also been investigated based on the chemical bonding between the constituents and the rigidity behaviour of the system’s network.

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

Nonlinear Optics in Thin Films

1989 ◽  
Author(s):  
G. I. Stegeman ◽  
C. T. Seaton
Keyword(s):  
Thin Films ◽  
Nonlinear Optics
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