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.
The environmental production of handmade carpets considering the application of natural materials; fibers, dyes, and mordants helps us benefit from the advantages of using renewable sources of raw ...materials. Metal salts are frequently employed as mordants to improve the fastness qualities. This article aims to investigate the yellow appearance of handmade carpets achieved by applying biomordants instead of metallic ones through spectral and colorimetric analysis. This method involved using reseda as a natural dye, yellow and black myrobalan as biomordants, and alum as a metallic mordant. After pre-mordanting and dyeing of the wool yarns, the achieved colors, color strengths, and key fastness properties were compared. The findings showed that using biomordants leads to appropriate color strengths and fastness qualities in addition to expanding the color gamut. Gratefully, the outcomes of current research guarantee to achieve the yellow appearance in Iranian handmade carpets through totally the novel eco-friendly procedure.
The chemical structure engineering of photosensitizers has a major role in photovoltaic devices such as dye-sensitized solar cells. Thus, a novel dye system was designed and prepared with contained ...indigo group for increasing light resistance as well as cyanoacrylic acid for improving the interaction. All intermediates and dyes were purified and analyzed using FTIR, HNMR, CHN and UV–Visible. The results showed that all the expected dye chemical structures have been achieved. Two semiconductors namely titanium dioxide and Na-doped titanium dioxide, were coated with the synthesized dye to prepare photoanode. All prepared samples illustrated blue shift in UV–Visible due to H-aggregation of dyes on the semiconductor. The energy level of dyes was investigated by Cyclic Voltammetry technique and DFT calculation. The results confirmed the possibility of using dyes in the structure of dye-sensitized solar cells. All prepared dyes were utilized as photosensitizers in dye-sensitized solar cells. The efficiency of Dye 6 in dye-sensitized solar cells based on titanium dioxide and its Na-doped derivative was 7.17% and 7.56%, respectively. Optical devices based on Na-doped semiconductor showed superior performance to those based on pristine titanium dioxide.
•Six new metal free organic dyes with D-π-A structure were synthesized.•Use of indoxyl 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.
Two novel metal free organic dyes based on thioindigo were prepared and used as sensitizers in dye-sensitized solar cells. The synthesized dyes together with their corresponding intermediates were ...purified and characterized by analytical techniques. Such techniques confirmed the corresponding structures of dyes and their intermediates and the yield of all the stages of dye preparation were calculated to be above 75%. Fluorometric analyses show fluorescence in the red region of the visible spectrum for both dyes. Oxidation potential measurements for both dyes ensured an energetically permissible and thermodynamically favourable charge transfer throughout the continuous cycle of photo-electric conversion. Finally, dye sensitized solar cells were fabricated in order to determine the photovoltaic behaviour and conversion efficiencies of each dye. Such evaluations demonstrate rather high conversion efficiencies of 6.10% and 6.45% for such simple structured dyes 1 and 2, respectively.
•Two novel organic dyes based on thioindigo for DSSCs were synthesized.•Use of thioindoxyl, as the electron donor, as well as a stable light fast base.•Both dyes showed J-type aggregation on nano TiO2.•The dyes shows high PCE (η D1 = 6.10% and η D2 = 6.45%) in standard devices.
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•Two new TADF dyes with D-A-D' structure were designed and synthesized.•The emission color changes under well grinding and stimulation.•Electron and Hole mobilities were measured by ...SCLC and TOF methods, respectively.•The maximum external quantum efficiency of the doped OLEDs was achieved to 13.41%.
In this study, we designed, engineered and investigated two new thermally activated delayed fluorescence (TADF) dyes obtained from D–A–D′ type, consisted of 2-(9H-carbazol-9-yl)-3-(3-methoxy-9H-carbazol-9-yl)-9H-xanthen and 2-(3,6-di-tert-butyl-9H-carbazol-9-yl)-3-(3-methoxy -9H-carbazol-9-yl)-9H-xanthen. In these dyes, xanthen derivative and carbazole derivatives have played important roles as an acceptor and two unsymmetrical donor units. In addition, the photophysical properties of these dyes were evaluated by the UV–VIS absorption, photoluminescence spectroscopy and photoluminescence decay lifetime analysis in solution, initial dye, non-doped and doped solid state (neat–film) at different temperatures and under the vacuum-ambient. Substitution's strong effect of the donor units was impressive; where, the dyes' ionization potential values were achieved as 5.53 and 5.62 eV. The charge mobility measurements of dyes were carried out using two different methods of spacecharge–limited current (SCLC) and time of the flight (TOF). Appropriate extracted results proved dyes' promising application as an emitter layer in organic light emitting diodes (OLEDs), through the photophysical properties, aggregation induced emission enhancement (AIEE) phenomenon, and high intensity of emission spectrum spanning the large part of visible area and good thermal stability. The solution process and physical evaporation deposition (PVD) procedure were tandemly performed in order to coat the layers and fabricate non-doped and doped OLEDs. The low turned on voltage' values of OLEDs were recorded in the range of 4.08 to 5.31 V. Furthermore, the maximum values of brightness, current, power and external quantum efficiency were achieved as 72565 cd/m2, 37.32 cd/A, 20.99 lm/W and 13.41%, respectively.
•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.
Acceptor electron groups play a key role in sensitizer proficiency in the DSSCs. To study this effect, a variety of acceptor electron groups were placed on a common scaffold. In this way, various intermediates and dyes were engineered, synthesized, purified and identified. Titanium dioxide and Na-doped TiO2 were employed to prepare of nanocrystalline layer of the photovoltaic devices. The blue movement was beholden in the UV–Visible test the coated photosensitizers on nanoparticle due to the J-type aggregation. 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 Na-doped TiO2 or TiO2. The photovoltaic device, which contains Dye 2, has the highest Jsc. The operation of photovoltaic device based on titanium dioxide is lower than that of Na-doped TiO2.
Photovoltaic systems, for example, dye-sensitized solar cells (DSSCs), are one of the useful tools for producing renewable and green energy. To develop DSSCs technology, it is necessary to overcome ...obstacles such as the need for expensive compounds. A series of DSSCs were designed and manufactured based on natural dyes extracted from cornelian cherry, black pomegranate, ruby grape, and tangerine peel as photosensitizers. The performance, structure, and interaction of the prepared extracts were evaluated by ultraviolet–visible spectroscopy, cyclic voltammetry, and Fourier transform infrared spectroscopy. Then, the prepared low-cost green dyes were employed in the preparation of DSSCs. A new MoS2/GO hybrid or composite was also employed instead of platinum. The synthesized MoS2/GO hybrid or composite was evaluated by field emission scanning electron microscopy and the results illustrated that the desired compound was synthesized successfully. Finally, DSSCs were prepared using MoS2/GO hybrid or composite and compared with that containing platinum. Under same conditions, the DSSCs with MoS2/GO composite illustrated better efficiency than MoS2/GO hybrid. The co-sensitization of Pt-free DSSC based on natural dyes has been studied for the first time in this work, which provides with expanding photovoltaic absorption range.
•Low-cost natural dyes were used as individual- or co-sensitizers in DSSCs.•MoS2/GO hybrids or composites were prepared using the hydrothermal method.•MoS2/GO hybrids and composites were used to replace Pt counter electrodes in DSSCs.•Photovoltaic performance of MoS2/GO-based DSSCs was investigated and evaluated.•DSSCs using hybrids/composites exhibited up to 95% of the PCE of Pt-based devices.
A series of dye-sensitized solar cells were designed and manufactured based on natural dyes extracted from red grape, red onion peel, radish, sour orange peel, and sambucus ebulus, as ...photosensitizers. The UV–Visible technique was served to determine maximum adsorption of natural extract and pre-dyed photoanode. The Fourier transform infrared analysis was employed to track the presence of functional groups. The cyclic voltammetry method was used to assess the possibility of charge transfer from a dried natural dye to the photoelectrode. The performance of natural-based dye-sensitized solar cells was subsequently determined. Fabricated devices were examined for power conversion efficiency (PCE), individually, in co-sensitized (Co-DSSC) arrangement and in tandem (T-DSSC) with each other. In case of individual device, the highest possible PCE among studied systems was ca. 1.47%, belonged to radish extract. For T-DSSC and Co-DSSC, 1.59 and 2.59% were respectively the highest values of PCE obtained in this work. The use of T-DSSC device has been applied for the first time in this work, which provides with expanding photovoltaic absorption range.
•Natural-based dye sensitizers extracted and applied in fabrication of DSSCs.•Dyes were red grape, red onion peel, radish, sour orange peel, and sambucus ebulus.•Individual, co- and tandem-sensitized configurations are compared for efficiency.•Highest efficiency was due to red grape and radish in co-DSSC device.•Tandem was firstly introduced here and resulted in expanded absorption wavelength.
Nanocomposite consisting of 5 mol% crystalline CuI-doped hydroxyapatite (HA) was prepared for the first time by facile chemical method and calcined at different temperatures such as 300 °C, 500 °C, ...700 °C and 900 °C. In this study, HA played a role as the matrix and CuI was the reinforcement. The effect of calcination temperature on XRD pattern, TEM, SEM, BET, FTIR, luminescence intensity, photoluminescence quantum yield (PLQY), fluorescence lifetime, charge mobility measurements, electronic speckle pattern interferometry and mechanical properties were investigated. The modified Scherrer equation of the composites showed that the size of the particles increased with increasing calcination temperature from 66.64 to 87.20 nm. The photoluminescence intensity of CuI (5 mol%)/HA was quenched at room temperature, while the represented constant decay time for the calcined compound was increased at 700 °C. Furthermore, the CIE coordinates were shown 0.39333, 0.18493 for CuI (5 mol%)/HA calcined at 700 °C. The charge mobility values of the nanocomposites were extracted by space-charge limited current (SCLC) method and the range of effective mobility was from 3.645 × 10−4 to 6.697 × 10−4 cm2V−1s−1. Mechanical properties were fully discussed via ASTM-E9 standard and CuI (5 mol%)/HA calcined at 900 °C was in better range than other compounds, the σyc and hardness values were reported 7.32 Mpa and 40.81 HV respectively. Speckle interferometry was used to demonstrate that there was no large imperfection in the surface of each sample. The components were very sensitive to the calcination temperatures. In other words, the combination of CuI (5 mol%)/HA showed that the replacement of Cu ions with Ca was helpful to improve the photophysical and mechanical properties.
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•Facile synthesis of the CuI (5 mol%)–doped HA was performed.•The effect of calcination temperatures at 300 °C, 500 °C, 700 °C and 900 °C on the photophysical and mechanical properties was investigated.•Most of the properties was increased with increasing calcination temperature at 700 °C.•The effective hole mobility was found by SCLC method and the values recorded in the range from 3.645 × 10−4 to 6.697 × 10−4 cm2V−1s−1.
Agricultural waste is an unwanted material that is not only unmarketable, but also has secondary costs such as environmental pollution. Oleaster, also known as olive Russian fruit, has various uses, ...but it also produces waste such as seeds and peels. Oleaster fruit and all its parts are tannin rich, which can be utilized as natural mordant. Improvement of fastness and color properties of natural dyed fibers is obtained by using mordant. The employing of this mordant is effective in reducing agricultural waste and the production of dyeing chemical waste. Reseda extract was utilized as natural dye to investigate the color characteristics. The study of the phenolic percentage of different components of the Oleaster fruit, including peel, seed, and flesh, showed that each of these materials can be used as natural mordant. The formation of physical bonds in the presence of all kinds of mordant was investigated using the FTIR method, and the results showed that their performance is similar and they are effective in surface treatment of wool. Investigation of color characteristics of the yarns showed that the color strength increases in the presence of mordant. Studying the fastness of yarns dyed with ISO methods showed that the samples have high washing fastness.
