Assessment of tissues' inhomogeneous optical properties by a cost-effective microscope based on LED illumination

Author(s):  
Yinxu Bian ◽  
Qiulan Liu ◽  
Cuifang Kuang ◽  
Haifeng Li
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.


2021 ◽  
Author(s):  
Prabhpreet Singh ◽  
Navdeep Kaur

Bay-functionalization of perylene diimide (PDI) dye provide scope for modulating the optical properties of PDI. Symmetrical functionalization at 1,7-position of bay-region of PDI offered limited scope for tunability of photo...


Nanoscale ◽  
2018 ◽  
Vol 10 (16) ◽  
pp. 7581-7588 ◽  
Author(s):  
Manonmani Mohandoss ◽  
Soujit Sen Gupta ◽  
Ramesh Kumar ◽  
Md Rabiul Islam ◽  
Anirban Som ◽  
...  

This paper describes a labour-efficient and cost-effective strategy to prepare few-layered reduced graphene oxide like sheets from graphite.


Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 578
Author(s):  
Diana M. Mena Romero ◽  
David Victoria Valenzuela ◽  
Cristy L. Azanza Ricardo

Cu 2 ZnSnS 4 (CZTS) is a quaternary semiconductor that has emerged as a promising component in solar absorber materials due to its excellent optical properties such as band-gap energy of ca. 1.5 eV and significant absorption coefficient in the order of 10 4 cm − 1 . Nevertheless, the energy conversion efficiency of CZTS-based devices has not reached the theoretical limits yet, possibly due to the existence of antisite defects (such as Cu Zn or Zn Cu ) and secondary phases. Based on electronic similarities with Zn, Mg has been proposed for Zn substitution in the CZTS structure in the design of alternative semiconductors for thin-film solar cell applications. This work aims to study the properties of the CZTS having Mg incorporated in the structure replacing Zn, with the following stoichiometry: x = 0, 0.25, 0.5, 0.75, and 1 in the formula Cu 2 Zn 1 − x Mg x SnS 4 (CZ-MTS). The semiconductor was prepared by the hot injection method, using oleylamine (OLA) as both surfactant and solvent. The presence and concentration of incorporated Mg allowed the fine-tuning of the CZ-MTS semiconductor’s structural and optical properties. Furthermore, it was observed that the inclusion of Mg in the CZTS structure leads to a better embodiment ratio of the Zn during the synthesis, thus reducing the excess of starting precursors. In summary, CZ-MTS is a promising candidate to fabricate high efficient and cost-effective thin-film solar cells made of earth-abundant elements.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Aumber Abbas ◽  
Tanveer A. Tabish ◽  
Steve J. Bull ◽  
Tuti Mariana Lim ◽  
Anh N. Phan

AbstractGraphene quantum dots (GQDs), a novel type of zero-dimensional fluorescent materials, have gained considerable attention owing to their unique optical properties, size and quantum confinement. However, their high cost and low yield remain open challenges for practical applications. In this work, a low cost, green and renewable biomass resource is utilised for the high yield synthesis of GQDs via microwave treatment. The synthesis approach involves oxidative cutting of short range ordered carbon derived from pyrolysis of biomass waste. The GQDs are successfully synthesised with a high yield of over 84%, the highest value reported to date for biomass derived GQDs. As prepared GQDs are highly hydrophilic and exhibit unique excitation independent photoluminescence emission, attributed to their single-emission fluorescence centre. As prepared GQDs are further modified by simple hydrothermal treatment and exhibit pronounced optical properties with a high quantum yield of 0.23. These modified GQDs are used for the highly selective and sensitive sensing of ferric ions (Fe3+). A sensitive sensor is prepared for the selective detection of Fe3+ ions with a detection limit of as low as 2.5 × 10–6 M. The utilisation of renewable resource along with facile microwave treatment paves the way to sustainable, high yield and cost-effective synthesis of GQDs for practical applications.


2014 ◽  
Vol 16 (37) ◽  
pp. 20127-20137 ◽  
Author(s):  
F. A. La Porta ◽  
J. Andrés ◽  
M. S. Li ◽  
J. R. Sambrano ◽  
J. A. Varela ◽  
...  

We demonstrated phase control, mediated by the presence of tetrabutylammonium hydroxide, in the growth of ZnS crystals by using a cost effective MAS method; a very moderate temperature (140 °C) and a very fast reaction time are sufficient to produce nanostructures with a good degree of crystallinity.


MRS Advances ◽  
2020 ◽  
Vol 5 (21-22) ◽  
pp. 1133-1143 ◽  
Author(s):  
R. Akoba ◽  
G. G. Welegergs ◽  
M. Luleka ◽  
J Sackey ◽  
N Nauman ◽  
...  

ABSTRACTA novel technique providing a cost effective sustainable wet chemical etching method of synthesizing black Moly thin films rapidly has been presented. A top- down method for fabricating MoO3 has been investigated to understand the effect of chemical etchant concentration on the structural, morphological and optical properties of the thin films on Mo substrates. The XRD patterns demonstrated the formation of Tugarinovite MoO2 films on Mo substrate after annealing at 500°C in a vacuum. In this work, we developed nanostructured MoO3 on Mo substrate solar absorber, with a high solar absorptance of over 89%. These results suggest that solar absorbers made from refractory metal oxide nanostructures can be used for solar thermal applications.


2020 ◽  
Vol 8 (5) ◽  
pp. 4609-4613

Meeting the demand of paper and paper product requirement and at the same time decreasing the availability of fibrous raw materials, keeping an eye on cost effectiveness is challenging. Thus, recycling of paper is an alternative. Corrugated box, old newspapers and office waste papers are the sources of raw materials for paper and paper product industries. Deinking is an important step for recycling of old waste writing, printing and newsprint papers. The efficiency of ink separation in the process of waste paper recycling depends on the ink properties, kind of the additives, surfactants used, age of waste papers, the printing techniques and printing conditions. In general, deinking process consumes a large amount of chemicals which makes this method expensive, pollution intensive and even quality is compromised. In this study the effectiveness of surfactants like benzene dodecyl sulphonate, lauryl benzene sulphonate and sodium carbonate for cost effective deinking process by optimizing the chemical doses has been studied. The physical strength and optical properties of the paper after deinking was also explored. The surfactant better for both physical strength properties and optical properties of paper is identified to be the sodium dodecyl benzene sulfonate.


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