Effect of Annealing on Optical and Structural Properties of Rutile TiO2 Nanoarrays

2015 ◽  
Vol 34 ◽  
pp. 23-27
Author(s):  
A.H. Mayabadi ◽  
V.S. Waman ◽  
A.M. Funde ◽  
H.M. Pathan ◽  
S.R. Jadkar

One dimensional rutile-TiO2 nanoneedles (NNs) and nanorods (NRs) were grown directly on transparent conductive Fluorine-doped SnO2-coated (FTO) glass substrates using Chemical Bath Deposition (CBD) method. Titanium (III) chloride was used as the precursor, followed by annealing at 200°C. The heat treatment leads to the conversion of TiO2 nanoneedles into nanorods. Optical studies revealed that rutile-TiO2 thin films have a high absorption coefficient and a direct bandgap which decreased slightly (3.14-3.09 eV) by applying heat treatment .The ease of deposition of rutile-TiO2 nanocomposite with different morphologies at low temperature provides a new insight for potential applications in solar cells, sensors, catalysis and separation technology.

2013 ◽  
Vol 24 ◽  
pp. 176-183
Author(s):  
Santosh Mane ◽  
Pandurang Pingale ◽  
Vikram Karande ◽  
Lalasaheb Deshmukh

Cd1-xCoxS (0 x 0.5) thin films have been deposited by liquid phase chemical bath deposition method on glass substrate from a complex liquid phase formed by equimolar volumes of cadmium sulphate, thiourea and cobalt sulphate. For deposition various preparative parameters, such as speed, temperature, pH, and time were optimized and found to be 70 ± 2 rpm, 56 °C, 11±0.2 and 80 min. respectively. The samples were thin, uniform and tightly adherent with colour changing from orange red to dark chocolate as x was varied from 0 to 0.5. The films were characterized to evaluate the surface morphology, composition and optical measurements. The surface morphologies of these films revealed random orientation of the crystallites of elongated rhomboids with sharp and clear edges having leaf like appearance. The grain size is found to be enhanced continuously from x = 0 to x = 0.1 with fine and more clear grain boundaries and decreased for higher x values. Energy Dispersive X-ray analysis suggests that the deposits are Cd rich. The optical studies were performed on these samples in the range of wavelengths between 500 nm to 1300 nm and yield a high absorption coefficient (α 104-105 cm-1) with a direct type of transitions. The estimated band gap decreased from 2.42 eV to 1.94 eV as x was varied from 0 to 0.5.


Author(s):  
Minakshi Chaudhary ◽  
Yogesh Hase ◽  
Ashwini Punde ◽  
Pratibha Shinde ◽  
Ashish Waghmare ◽  
...  

: 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.


Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ki Young Lee ◽  
Kwang Wook Yoo ◽  
Youngsun Choi ◽  
Gunpyo Kim ◽  
Sangmo Cheon ◽  
...  

Abstract The topological properties of photonic microstructures are of great interest because of their experimental feasibility for fundamental study and potential applications. Here, we show that robust guided-mode-resonance states exist in photonic domain-wall structures whenever the complex photonic band structures involve certain topological correlations in general. Using the non-Hermitian photonic analogy of the one-dimensional Dirac equation, we derive essential conditions for photonic Jackiw-Rebbi-state resonances taking advantage of unique spatial confinement and spot-like spectral features which are remarkably robust against random parametric errors. Therefore, the proposed resonance configuration potentially provides a powerful method to create compact and stable photonic resonators for various applications in practice.


Author(s):  
Panagiota Koralli ◽  
Spyridon Tsikalakis ◽  
Maria Goulielmaki ◽  
Stella Arelaki ◽  
Janina Müller ◽  
...  

Conjugated polymer nanoparticles (CPNs) have emerged as a new promising class of cancer theranostic agents due to their desirable optical features, such as high absorption coefficient and photoluminescence quantum yields,...


2021 ◽  
Author(s):  
Qidong Kang ◽  
Fei Yang ◽  
Xinyu Zhang ◽  
Ziyu Hu

Since lead has a very high absorption coefficient μ, that the radiations from within the bulk material do not penetrate the layers. While, the oxygen and water (O2 and H2O)...


Author(s):  
Chen Qian ◽  
Jianjun Li ◽  
Kaiwen Sun ◽  
Chenhui Jiang ◽  
Jialiang Huang ◽  
...  

Antimony selenosulfide, Sb2(S,Se)3, has emerged as a promising light-harvesting material for its high absorption coefficient, suitable bandgap, low-toxic and low-cost constituents. However, the poor stability and high cost of widely...


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