Blueshift in optical band gap in nanocrystalline Zn1−xCaxO films deposited by sol-gel method

2009 ◽  
Vol 95 (3) ◽  
pp. 031901 ◽  
Author(s):  
Kamakhya Prakash Misra ◽  
R. K. Shukla ◽  
Atul Srivastava ◽  
Anchal Srivastava
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method

scholarly journals Synthesis, characterization and optical band gap of Pirochromite (MgCr2O4) Nanoparticles by Stearic Acid Sol-Gel Method

2016 ◽  
pp. 173-180 ◽  
Author(s):  
Ehsan Jafarnejad ◽  
Salah Khanahmadzadeh ◽  
Fatemeh Ghanbary ◽  
Morteza Enhessari
Keyword(s):  
Stearic Acid ◽  
Band Gap ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method

scholarly journals Structural and Optical Properties of ZnO Thin Films Prepared by Molecular Precursor and Sol–Gel Methods

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 132 ◽  
Author(s):  
Theopolina Amakali ◽  
Likius. S. Daniel ◽  
Veikko Uahengo ◽  
Nelson Y. Dzade ◽  
Nora H. de Leeuw
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Zno Thin Films ◽  
Structural And Optical Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Molecular Precursor

Zinc oxide (ZnO) is a versatile and inexpensive semiconductor with a wide direct band gap that has applicability in several scientific and technological fields. In this work, we report the synthesis of ZnO thin films via two simple and low-cost synthesis routes, i.e., the molecular precursor method (MPM) and the sol–gel method, which were deposited successfully on microscope glass substrates. The films were characterized for their structural and optical properties. X-ray diffraction (XRD) characterization showed that the ZnO films were highly c-axis (0 0 2) oriented, which is of interest for piezoelectric applications. The surface roughness derived from atomic force microscopy (AFM) analysis indicates that films prepared via MPM were relatively rough with an average roughness (Ra) of 2.73 nm compared to those prepared via the sol–gel method (Ra = 1.55 nm). Thin films prepared via MPM were more transparent than those prepared via the sol–gel method. The optical band gap of ZnO thin films obtained via the sol–gel method was 3.25 eV, which falls within the range found by other authors. However, there was a broadening of the optical band gap (3.75 eV) in thin films derived from MPM.

Morphology and Optical Studies of (1-x)ZnAl2O4 – xSiO2 Thin Films Prepared by Sol-Gel Method

2014 ◽  
Vol 895 ◽  
pp. 63-68 ◽  
Author(s):  
Mohd Syafiq Zulfakar ◽  
Huda Abdullah ◽  
Wan Nasarudin Wan Jalal ◽  
Sahbudin Shaari ◽  
Zainuddin Zalita
Keyword(s):  
Thin Film ◽  
Particle Size ◽  
Band Gap ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Average Particle Size ◽  
Average Crystallite Size ◽  
Average Particle ◽  
Gel Method ◽  
Sol Gel Method

The effect of morphological structures and optical band gap of (1-x)ZnAl2O4xSiO2samples with compositions ofx= 0.00, 0.05, 0.10 and 0.15 were prepared by sol-gel method. Spin coating technique was used to deposited the (1-x)ZnAl2O4xSiO2as a thin film and to investigate the structural and optical band gap. The produced thin film samples were annealed at 450 °C for 1h. Field emission scanning electron microscope (FESEM) was used to investigate the surface morphology of the samples. The average particle size for (1-x)ZnAl2O4xSiO2is about 331.23 nm. The particle size are tend to increase as the composition of SiO2increased. XRD analysis shows the formation of cubic structure phase and dominant peak has been observed with Miller Indices (311) plane. The average crystallite size,Dwas calculated with average size about 8 13 nm. The optical band gap was calculated for (1-x)ZnAl2O4xSiO2samples and it was found within range of 3.34 to 3.94 eV.

scholarly journals Effects of La Dopant on Nanocluster Size and Optical Band Gap of CdO Films Prepared by Sol-Gel Method

2013 ◽  
Vol 124 (1) ◽  
pp. 125-127 ◽  
Author(s):  
Z.A. Alahmed ◽  
Z. Serbetçi ◽  
F. Yakuphanoglu
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Cdo Films

scholarly journals Bismuth Oxide Prepared by Sol-Gel Method: Variation of Physicochemical Characteristics and Photocatalytic Activity Due to Difference in Calcination Temperature

2020 ◽  
Vol 21 (1) ◽  
pp. 108
Author(s):  
Yayuk Astuti ◽  
Brigita Maria Listyani ◽  
Linda Suyati ◽  
Adi Darmawan
Keyword(s):  
Photocatalytic Activity ◽  
Band Gap ◽  
Calcination Temperature ◽  
Bismuth Oxide ◽  
Sol Gel ◽  
Physicochemical Characteristics ◽  
Band Gap Energy ◽  
Gel Method ◽  
Sol Gel Method ◽  
Body Center Cubic

Research on synthesis of bismuth oxide (Bi2O3) using sol-gel method with varying calcination temperatures at 500, 600, and 700 °C has been done. This study aims to determine the effect of calcination temperature on the characteristics of the obtained products which encompasses crystal structure, surface morphology, band-gap energy, and photocatalytic activity for the decolorization of methyl orange dyes through its kinetic study. Bismuth oxide prepared by sol-gel method was undertaken by dissolving Bi(NO3)3·5H2O and citric acid in HNO3. The mixture was stirred then heated at 100 °C. The gel formed was dried in the oven and then calcined at 500, 600, and 700 °C for 5 h. The obtained products were a pale yellow powder, indicating the formation of bismuth oxide. This is confirmed by the existence of Bi–O and Bi–O–Bi functional groups through FTIR analysis. All three products possess the same mixed crystal structures of α-Bi2O3 (monoclinic) and γ-Bi2O3 (body center cubic), but their morphologies and band gap values are different. The higher the calcination temperature, the larger the particle size and the smaller the band gap value. The accumulative differences in characteristics appoint SG700 to have the highest photocatalytic activity compared to SG600 and SG500 as indicated by its percent degradation value and decolorization rate constant.

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