Dyeing is a state-of-the-art realm of textile engineering, however, the emphasis on petroleum-based products is now shifting towards green fibers, particularly, green manufacturing processes. In the ...present work, a natural mordant, sumac, was extracted and used alone and in combination with alum (a mineral mordant) in silk fibers dyeing with madder and Reseda green dye to make the green production of Iranian carpet possible. The FT-IR ATR spectra of the washed, mordanted, and mordanted dyed silk fibers revealed bonding between silk fibers and green materials. The color of the silk fibers dyed with madder and Reseda extraction was quantified in terms of CIELab (
L
*,
a
*, and
b
*) and
K/S
values. The effects of different treatments on fastness properties including light, wash, and rubbing fastness were assessed by ISO standard test method.
The coloring behavior of santalin, a natural reddish-brown dye derived from sandalwood, has been investigated in this work for the dyeing of silk fabrics while being heated in MW radiation. Microwave ...(MW) radiation up to 5 min has been employed to isolate colorant (Santalin) from red sandalwood (Ptrecarpus santalinus) in selected medium, and bio-mordants in competing with salts as chemical-mordants have been included. Statistical analysis was made and dyeing variables were selected for getting dark shades though mordants. MW treatment for 3 min. to both extract and fabric was selected and mild dyeing conditions were optimized statistically to get dark shades. On applying chemical mordants, selected amount of salts of Al+3, Fe+2 and T.A. before and after dyeing, has given good results. Comparatively, selected extracts of plant based sources have shown colorfast shades of high strength. The MW radiation has excellent potential to extract dye form plants using optimum medium through less time and energy, and the application of plant extracts along with sustainable salts have developed colorfast shades.
The aim of the present research was to prepare new acid dyes based on naphthalimides. In this respect a series of monoazo acid dyes have been obtained using 4-amino-N-methyl (alternatively ...N-butyl)-1,8-naphthalimide, aniline and p-nitroaniline as diazo components. 2-Naphthol-6-sulfonic acid (Schaeffer’s acid) and 1-naphthol-8-amino-3,6-disulfonic acid (H-acid) were used as coupling components. The spectrophotometric properties of the synthesized dyes were investigated in various solvents and compared with analogues azobenzene dyes. It is found, when acid dyes are applied in various solvents and different pH, additional bathochromically shifted bands of different intensity appear in the electronic spectra. This effect is caused by the occurrence of the equilibrium of azo and hydrazone forms in the dyes. The synthesized acid dyes were applied on wool fabrics in order to consider their dyeing properties, fastnesses and the obtainable color gamut. The synthesized dyes represented that they have the ability of dyeing wool and polyamide fabrics and give red to violet hues with good wash, medium light, and good milling and perspiration fastnesses.
Cosensitization using two organic dyes with supplementary absorption spectra on a photoelectrode is an effective method for improving the photovoltaic properties of dye-sensitized solar cells. Two ...organic dyes based on indigo and thioindigo have been synthesized, purified, and used to sensitize solar cells with spectral response extending across the entire visible region. To improve their photoelectric properties, different molar ratios were investigated, yielding total efficiency of 6.17% at dye 1:dye 2 = 4:6. The effect of the concentration of Cheno antiaggregation agent on the performance of the dye-sensitized solar cells was also considered. The results demonstrate that higher conversion efficiency (
η
= 6.82%) was achieved with 10 × 10
−3
M Cheno. Finally, the performance of cosensitized solar cells was measured at different temperatures between 10°C and 50°C. The results indicated that
J
sc
decreased with increasing temperature, directly affecting the conversion efficiency.
Purpose
The purpose of this paper is to introduce flexible dye-sensitized solar cells (FDSSCs).
Design/methodology/approach
In the third generation solar cells, glass was used as a substrate, which ...due to its high weight and fragility, was not possible to produce continuously. However, in flexible solar cells, flexible substrates are used as new technology. The most important thing may choose a suitable substrate to produce a photovoltaic (PV) device with optimal efficiency.
Findings
Conductive plastics or metallic foils are the two main candidates for glass replacement, each with its advantages and disadvantages. As some high-temperature methods are used to prepare solar cells, metal substrates can be used to prepare PV devices without any problems. In contrast to the advantage of high thermal resistance in metals, metal substrates are dark and do not transmit enough light. In other words, metal substrates have a high loss of photon energy. Like all technologies, PV devices with polymer substrates have technical disadvantages.
Practical implications
In this study, the development of FDSSCs offers improved photovoltaic properties.
Social implications
The most important challenge is the poor thermal stability of polymers compared to glass and metal, which requires special methods to prepare polymer solar cells. The second important point is choosing the suitable components and materials for this purpose.
Originality/value
Dependence of efficiency and performance of the device on the angle of sunlight, high-cost preparation devices components, limitations of functional materials such as organic-mineral sensitizers, lack of close connection between practical achievements and theoretical results and complicated fabrication process and high weight.
Three derivatives of food azo dye were investigated (Dyes 1, 2 and 4) by theoretical and experimental tools. Photophysical properties, based on theoretical estimations, experimental evaluations, ...electrochemical and photoelectrical properties were discussed. The compounds exhibited efficient emission of solid state with maximum fluorescence intensity at the range of 517–646 nm and PLQY (photoluminescence quantum yield) values at the range of 9–17% in non-doped solid state and 13–39% in doped solid state. In this study 90 wt percent of PBD (2-(4-tert-Butylphenyl)-5-(4-biphenylyl)-1,3,4-oxadiazole) have been used as the electron transporting host who derived balanced charge carrier transport for high internal and external efficiency of OLEDs (organic light emitting diodes). Ionization potential for compounds was found to be comparable (5.85 and 6.18 eV) by photoelectron emission spectrometry. According to the fabrication of devices for gaining charge mobility the layers of the dyes showed properties as a bipolar charge transporting with balanced hole and electron mobility and the values reaching to 1.27 × 10−4 cm2/Vs and 1.09 × 10−4 cm2/Vs respectively at high electric fields. Furthermore, OLEDs consist of azo dyes as an emitter layer fabricated by PVD (physical evaporation deposition) method and the maximum values of the best device showed, consist of, the low turn on voltage of 2.69 V and values of brightness, current efficiency, power efficiency, EQE (external quantum efficiency) 16432.40 cd/m2, 8.20 cd/A, 6.95 lm/w, 4.89% respectively.
•Three metals free organic derivatives of food azo dye-based organic light emitting diode (OLED) emitters were considered.•Photoluminescence quantum yield (PLQY) values were at the range of 9–17% in non-doped solid state and 13–39% in doped solid state.•Their ionization potentials were in the range of 5.85–6.18 eV.•Hole and Electron mobility reached to 1.27 × 10−4 cm2/Vs and 1.09 × 10−4 cm2/Vs respectively at high electric fields.•10 %wt of dye 1 (food Yellow, Tartrazine) doped to the PBD (2-(4-tert-Butylphenyl)-5-(4-biphenylyl)-1,3,4-oxadiazole) showed maximum EQE (external quantum efficiency) of 4.89%.•Dye 1 containing COOH as the acceptor group is more capable for using fabrication of OLED and Solar cell, which is related to the stronger electron withdrawing ability than other food azo dyes.
Four novel fluorescent organic dyes DH1, DH2, DH3 and DH4 containing iminodibenzyl were prepared as photosensitizer for dye-sensitized solar cells. The fluorescence dyes and their corresponding ...intermediates were purified and characterized by analytical methods. The results confirmed the corresponding structure fluorescent dyes and their intermediates. The ultraviolet absorption investigation of fluorescent dyes in solution and on photoanode shows that the dyes form J-type aggregation on photoanode substrate. Fluorometric investigation shows fluorescence in the red region for all organic dyes. Redox properties and density functional theory calculation for all synthesized dyes ensured thermodynamically charge transfer from excited state to conduction band photoanode. Photophysical and photovoltaic properties of fluorescent dyes have been studied in dye-sensitized solar cells devices. The results show the rather high conversion efficiency of 4.48, 4.63, 4.95 and 5.09% of each individual dye, respectively.
The output of various donating substituents on the optical behavior of new photosensitizers in the solar cells was investigated. The pure intermediates and dyes were identified via an analytical ...procedure and confirmed the chemical structure. Zinc oxide and titanium dioxide were operated to fabricate the nanocrystalline layer of the solar cells. The UV–Visible spectra of all synthesized dyes on ZnO and TiO2 illustrated blue shift due to the J-aggregation of organic dyes on the semiconductor substrate. To predict the usability of dyes in the structure of the solar cells, two methods, DFT and CV were employed. Finally, the DSSCs devices were prepared based on synthesized dyes and ZnO or TiO2. The highest photocurrent was achieved for individual device-TiO2 sensitized with Dye 2 containing thioindigo and cyanoacrylic acid. The operation of photovoltaic device based on zinc oxide was lower than that of titanium dioxide.
•Six new metal free organic dyes with D-π-A structure were synthesized.•Use of thioindoxyl as well as a stable light fast base.•Two types of TiO2 and ZnO nanopartical were used to prepare of photoanode.•The highest photocurrent was achieved for individual DSSC based on Dye contain thioindigo and cyanoacrylic acid.
Purpose
The purpose of this paper is to study the substituent effect in dye-sensitized solar cells’ (DSSCs) performance. For this end, three new metal organic dyes with DPA structure were ...synthesized. For investigation of the substituent effect, two different anchoring groups, namely, 1,3-dioxo-1Hbenzdeisoquinolin-2(3H)-yl)benzenesulfonamides and 1,8-naphthalimide, were used.
Design/methodology/approach
Three organic dyes based on azo were selected, which contain various electron donor groups. Absorption properties of purified dyes were studied in solution and on photoelectrode (TiO2 and ZnO) substrate. DSSCs were prepared to determine the photovoltaic performance of each photosensitizer.
Findings
The results showed that all organic dyes form J-aggregation on the photoanode substrate. Cyclic voltammetry results for all organic dyes ensured an energetically permissible and thermodynamically favorable charge transfer throughout the continuous cycle of photo-electric conversion. The results illustrate conversion efficiencies of cells based on solution Dyes 1, 2 and 3 and TiO2 as 3.44, 4.71 and 4.82 per cent, respectively. The conversion efficiencies of cells based on solution Dye 1, 2 and 3 and ZnO are 3.21, 4.09 and 4.14 per cent, respectively.
Practical implications
In this study, the development of effect of assembling materials, offering improved photovoltaic properties.
Social implications
Organic dye attracts more and more attention because of its low-cost, facile route synthesis and less-hazardous properties.
Originality/value
To the best of the authors’ knowledge, the effect of anchoring agent and nanostructure on DSSCs performance was investigated for the first time.
Abstract
Due to the increasing effects of greenhouse gases and environmental pollution, the need for new clean energies like solar energy attracts much attention. Although the characteristics and the ...efficiency of green photovoltaic devices have been researched, the colour gamut achievable from those devices has not been studied. This study investigates the colour gamut of low‐cost dye‐sensitised solar cells (DSSCs). To do this, 14 natural dye extracts were obtained from herbal resources including dragon fruit, blueberry, mango, radish, yellow rose, red cabbage, sour pomegranate, beetroot, olive, green cabbage pepper, eggplant, parsley, bramble and cherry, and employed as photosensitiser in solar cells. Then, the colorimetric attributes of the photosensitisers were studied in three‐dimensional (3D)‐colour space, that is, CIELab, CIELCH and CIE1931 chromaticity diagram. Additionally, the convex hull method was employed to determine the colour gamut boundary and the corresponding colour gamut volume. Results showed that the majority of samples benefited from approximately 3°–82° of hue angle in
a
*
b
* diagram of CIELab colour space and showed the yellowish to reddish tint effects. In CIELCH colour order system, cherry and parsley showed the lowest and highest lightness attributes while the chroma property of samples varied from minimum 1.2 for eggplant to maximum 60.2 for the dragon fruit. Moreover, the results of using the convex hull method showed the volume of 7.73 × 10
4
that is bounded by the colour gamut of 3D colour points over the CIELab colour space.
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