scholarly journals Reducing the Energy Band Gap of Cobalt Hydroxide Nanosheets with Silver Atoms and Enhancing Their Electrical Conductivity with Silver Nanoparticles

ACS Omega ◽  
2021 ◽  
Author(s):  
Montakan Suksomboon ◽  
Ketsuda Kongsawatvoragul ◽  
Salatan Duangdangchote ◽  
Montree Sawangphruk
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
A. A. Faremi ◽  
S. S. Oluyamo ◽  
O. Olubosede ◽  
I. O. Olusola ◽  
M. A. Adekoya ◽  
...  

Abstract In this paper, energy band gaps and electrical conductivity based on aluminum selenide (Al2Se3) thin films are synthesized electrochemically using cathodic deposition technique, with graphite and carbon as cathode and anode, respectively. Synthesis is done at 353 K from an aqueous solution of analytical grade selenium dioxide (SeO2), and aluminum chloride (AlCl2·7H2O). Junctions-based Al2Se3 thin films from a controlled medium of pH 2.0 are deposited on fluorine-doped tin oxide (FTO) substrate using potential voltages varying from 1,000 mV to 1,400 mV and 3 minutes −15 minutes respectively. The films were characterized for optical properties and electrical conductivity using UV-vis and photoelectrochemical cells (PEC) spectroscopy. The PEC reveals a transition in the conduction of the films from p-type to n-type as the potential voltage varies. The energy band gap reduces from 3.2 eV to 2.9 eV with an increase in voltage and 3.3 eV to 2.7 eV with increase in time. These variations indicate successful fabrication of junction-based Al2Se3 thin films with noticeable transition in the conductivity type and energy band gap of the materials. Consequently, the fabricated Al2Se3 can find useful applications in optoelectronic devices.


2016 ◽  
Vol 846 ◽  
pp. 620-625 ◽  
Author(s):  
Hamizah Nadia Alias@Yusof ◽  
Hasiah Salleh ◽  
Mohd Ikmar Nizam Mohamad Isa

Conjugated polymers have been widely used for electronic purpose applications due to their numerous advantages. This has led many researches to pay their major attention in studying on characteristics of conjugated polymer thin films. The purpose of this study was to investigate the effect of undoped conjugated polymer thin films on their optical and electrical properties. Poly(3-thiophene acetic acid), Polypyrrole and Polythiophene thin film was fabricated on ITO glass substrate by using EIS. Film thickness, energy band gap and electrical conductivity of thin films were characterized by using profilometer, ultraviolet-visible spectrometer and four point probe method respectively. The thickness of each thin film varied between 50.534 nm to 97.03 nm. The result has shown that thicker film has lower energy band gap compared to the thinner one. However the electrical conductivity showed an opposite behavior.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Shujahadeen B. Aziz ◽  
Soran M. Mamand ◽  
Salah R. Saed ◽  
Ranjdar M. Abdullah ◽  
Sarkawt A. Hussein

Silver nanoparticles within a host polymer of chitosan were synthesized by using in situ method. Ultraviolet-visible spectroscopy was then carried out for the prepared chitosan : silver triflate (CS : AgTf) samples, showing a surface plasmonic resonance (SPR) peak at 420 nm. To prepare polymer composites with reduced energy band gap, different amounts of alumina nanoparticles were incorporated into the CS : AgTf solution. In the present work, the results showed that the reduced silver nanoparticles and their adsorption on wide band gap alumina (Al2O3) particles are an excellent approach for the preparation of polymer composites with small optical band gaps. The optical dielectric loss parameter has been used to determine the band gap experimentally. The physics behind the optical dielectric loss were interpreted from the viewpoint of quantum mechanics. From the quantum-mechanics viewpoint, optical dielectric loss was also found to be a complex equation and required lengthy numerical computation. From the TEM investigation, the adsorption of silver nanoparticles on alumina has been observed. The optical micrograph images showed white spots (silver specks) with different sizes on the surface of the films. The second semicircle in impedance Cole-Cole plots was found and attributed to the silver particles.


Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1512
Author(s):  
Changho Seo ◽  
Seongsoo Cho ◽  
Je Huan Koo
Keyword(s):  
Band Gap ◽  

We investigate why normal electrons in superconductors have no resistance. Under the same conditions, the band gap is reduced to zero as well, but normal electrons at superconducting states are condensed into this virtual energy band gap.


2008 ◽  
Vol 3 ◽  
pp. 97-102 ◽  
Author(s):  
Dinu Patidar ◽  
K.S. Rathore ◽  
N.S. Saxena ◽  
Kananbala Sharma ◽  
T.P. Sharma

The CdS nanoparticles of different sizes are synthesized by a simple chemical method. Here, CdS nanoparticles are grown through the reaction of solution of different concentration of CdCl2 with H2S. X-ray diffraction pattern confirms nano nature of CdS and has been used to determine the size of particle. Optical absorption spectroscopy is used to measure the energy band gap of these nanomaterials by using Tauc relation. Energy band gap ranging between 3.12 eV to 2.47 eV have been obtained for the samples containing the nanoparticles in the range of 2.3 to 6.0 nm size. A correlation between the band gap and size of the nanoparticles is also established.


2020 ◽  
pp. 111059
Author(s):  
B. Thapa ◽  
P.K. Patra ◽  
Sandeep Puri ◽  
K. Neupane ◽  
A. Shankar

Sign in / Sign up

Export Citation Format

Share Document