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Here, we synthesized metal-free organic dye (CCPICPB) with two carbazole donor groups and two anchoring groups that exhibit a panchromatic absorption in the near-infrared range of up to 750 nm. To study the photophysical properties of synthesized CCPICPB dye, the UV–Vis and cyclic voltammetric experiments were studied and the obtained results were validated with theoretical simulation studies. After that, the solvothermal approach is used to synthesize pristine anatase and calcium (Ca)-doped TiO2 microspheres with a smooth morphology. These microstructures are examined in depth using XRD, electron microscopy and electrochemical analysis methods. On TiO2 and Ca-doped TiO2 photoanode materials, we first evaluated the performance of CCPICPB dye. Upon our optimized experimental condition, the 3% Ca-TiO2 photoanode-based device exhibits an efficiency of 4.04%, which is greater than that of the pristine TiO2 photoanode-based device (2.93%). Because of the quicker electron transport in the Ca-TiO2 film, the short-circuit current density and efficiency of DSSCs were improved. Moreover, when the CCPICPB dye was used as a co-sensitizer with the common Ru(II) dye (Z907), interestingly it showed the highest efficiency (6.11%) when compared with Z907 alone (5.12%). This improved efficiency of the co-sensitized device resulted from greater VOC conjugated with improved JSC. The JSC was improved because CCPICB dye could compensate for the photocurrent loss caused by redox electrolyte while the VOC was improved because electron recombination was inhibited under the co-sensitization conditions. [ABSTRACT FROM AUTHOR]

We synthesized POBA dye and studied its performance as a sensitizer and co-sensitizer. In addition, we present a simple method for producing Ni-doped TiO2 with various molar concentrations for use as a photoanode in a DSSC. Further, poly(vinylidene fluoride)/polyethylene glycol (PVDF-PEG) gel polymer electrolytes (GPEs) having different concentrations of 1-n-hexyl-3-methylimidazolium iodide were prepared and optimized for usage in DSSCs. We initially tested the performance of POBA dye on TiO2 and Ni-doped TiO2 photoanode materials. Among the POBA sensitized devices, 4% Ni–TiO2 showed a high efficiency of 1.85%. Then, we sensitized Z907 dye on the 4% Ni–TiO2 photoanode, followed by sensitizing it with POBA, which compensated the absorption defect of the Z907 dye as well as filling the gap between the standard dye molecules. This approach enhances and broadens the absorption spectrum of the dyes by molecular filling, compensates for the lack of absorption of Z907, and reduces the recombination of charges. The Z907-based DSSC showed 4.52% efficiency, and after co-sensitization, the DSSC showed an increase in efficiency (5.77%). These findings show that co-sensitizers can cover the naked spectrum in the ultraviolet-visible region, fill the empty space on Ni–TiO2, and reduce recombination reactions. The main motive of this research is to enhance the photo-ability of sensitizers and metal-free co-sensitizers in a Ni–TiO2 photoanode and blend gel polymer electrolyte-based DSSCs. [ABSTRACT FROM AUTHOR]

Summary: To investigate the photovoltaic capabilities as a sensitizer and co‐sensitizer for dye‐sensitized solar cells (DSSCs), a new metal‐free organic dye (CDIB) was synthesized. In addition, different concentrations of 1‐n‐hexyl‐3‐methylimidazolium iodide ionic liquid (IL) doped poly(vinylidene fluoride‐hexafluoropropylene) gel polymer electrolytes are prepared and the high conductive electrolyte is used to fabricate the devices. The device having CDIB sensitizer and IL‐15% electrolyte showed an efficiency of 1.86%. Further, the effect of CDIB co‐sensitization on Z907 is examined. Consequently, the power conversion efficiency of DSSC with co‐sensitized dye is raised by 23.29%, from 4.55 to 5.61%, when compared to DSSCs with individual dyes. This improvement is mostly due to an increase in a short‐circuit current density and open‐circuit voltage. Highlights: Co‐sensitization is being used to enhance the performance of DSSCs.Poly(vinylidene fluoride‐hexafluoropropylene)‐based gel polymer electrolytes doped with different amounts of 1‐n‐hexyl‐3‐methylimidazolium iodide were prepared for improving the conductivity of electrolyte.A co‐sensitized DSSC has an efficiency of 5.61%.With co‐sensitization, both VOC and JSC increased significantly. [ABSTRACT FROM AUTHOR]

The existing energy situation demands not only the huge energy in a short time but also clean energy. In this regard, an integrated photo-supercapacitor device has been fabricated in which photoelectric conversion and energy storage are achieved simultaneously. A novel carbazole-based dye is synthesized and characterized for photosensitizer. The silver-doped titanium dioxide (Ag-TiO2) is synthesized, and it is used as photoanode material. Different concentrations of tetrabutylammonium iodide (TBAI)-doped polyvinyl alcohol–polyvinylpyrrolidone (PVA-PVP) blend polymer electrolytes are prepared, and their conductivity and dielectric properties were studied. Reduced graphene oxide (r-GO) is synthesized by a one-pot synthesis method and confirmed using Raman spectroscopy for counter electrode material in dye-sensitized solar cell (DSSC) and supercapacitor electrodes. The DSSC having 4% Ag-TiO2–based photoanode showed the highest efficiency of 1.06% (among r-GO counter electrodes) and 2.37% (among platinum counter electrodes). The supercapacitor before integration and after integration exhibits specific capacitance of 1.72 Fg−1 and 1.327 Fg−1, respectively. [ABSTRACT FROM AUTHOR]

Summary: In the present context of increasing population, renewable and sustainable energy alternatives are very much essential to satisfy the necessities of the world. To satisfy this growing demand, scientists are prioritizing the production of cost‐effective and high‐performance clean energy appliances. Dye‐sensitized solar cells (DSSCs) are one such material that is at the forefront of modern solar cell technologies. Being one of the main components of DSSCs, metal‐free organic dyes play a crucial role in light processing and electron injection. In recent times, carbazole (CZ)‐, triphenylamine (TPA)‐, and phenothiazine (PTZ)‐based derivatives have been identified as suitable alternatives to Ru(II) polypyridyl complexes because they are easy to synthesize and exhibit excellent thermal and electronic properties. This review focuses largely on the latest developments in the use of monoanchored and multianchored CZ, TPA, and PTZ scaffolds for DSSC applications and focuses especially on the correlation between molecular design and photovoltaic performance. The physical properties of devices can be adjusted through the sensitizer's strategic design that helps to improve the performance of the devices. We tabulated the photovoltaic parameters corresponding to all dyes presented in this review. Also, applications of additives are presented after the systematic review on CZ‐, TPA‐, and PTZ‐based dyes. [ABSTRACT FROM AUTHOR]

Due to the outstanding high power conversion efficiency and mechanical robustness, photovoltaic systems have become a perfect alternative to traditional sources of energy. This helps in fulfilling the human demand for renewable, inexpensive and compact electricity sources. The production of highly efficient flexible dye-sensitized solar cells (FDSSCs) has sparked a lot of attention in recent years. These FDSSCs are promising energy sources for battery-free and self-powered electronics, which have application in different sectors, including the Internet of Things. Due to the intermittent and unpredictable nature of solar radiation, photoelectric conversion devices fail to satisfy the criteria of constant power output. Owing to the emergence of rechargeable electric energy storage devices, the integration of FDSSCs and rechargeable electric energy storage systems has become a promising approach in solving this problem. This review focused on the recent developments in terms of the materials used to fabricate FDSSCs along with the working principle, challenges in FDSSCs and improvements made in photoanode, sensitizer, electrolytes and counter electrode materials. In addition, some of the general characterization methods for newly prepared flexible/rigid dye-sensitized solar cell materials and the device are summarized. The evolution of many forms of mainstream flexible integrated photorechargeable energy storage systems, prospects for the development of highly effective, reliable FDSSCs and their integrated devices have also been demonstrated. [Display omitted] • Recent advancements in flexible dye-sensitized solar cell materials are discussed. • Characterization methods for different components and produced devices are explored. • The developments of integrated flexible dye-sensitized solar cells are addressed. • The key outcomes and importance of each material used were highlighted. • Describes promising methods for improving and stabilizing the device efficiency. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells (DSSCs) are an efficient and versatile method of transforming the clean and most plentiful energy resources available. DSSC is translucent to some extent and relatively inexpensive than the traditional solar cell. Thus, it may be a possible source of electricity for the future. But other things need to be focused on before it is considered a viable commercial product. The review discusses these facets and the numerous changes the DSSC has experienced in the recent years. Photoelectric conversion systems struggle to fulfil the specifications of constant power output owing to the erratic and unstable characteristics of the solar radiation. With the evolution of rechargeable electric energy storage systems (ESSs), the integration of a DSSC and ESSs has developed into a promising approach to solve this issue. Here, we describe the working principle, recent progress of DSSCs, including photoanodes, sensitizers, electrolytes, and counter electrodes, and the use of DSSCs in energy storage, targeting DSSC and supercapacitor (SC) integrated devices. The future prospects for highly effective, reliable DSSC and DSSC-SC development have also been highlighted. [Display omitted] • Recent progress in dye sensitized solar cell materials are reviewed. • Developments of photo-supercapacitors are reviewed. • Highlighted main outcomes and significance of each material used. • Describes promising ways to stabilize and improvise the performance of the device. [ABSTRACT FROM AUTHOR]

In this study, a propeller-type molecule with a pyridine core (D) was designed and synthesized. Photophysical and electrochemical studies, along with theoretical DFT simulations, indicated that the molecule has suitable light absorption properties and frontier molecular orbital levels for usage as a sensitizer in dye-sensitized solar cells (DSSCs). Meanwhile, the standard dye Z-907 was chosen to investigate the effect of the synthesized molecule as co-adsorbent dye on DSSCs. Intriguingly, when compared to the D and Z907 -based devices, the performance of the co-sensitized Z907 + D cell exhibited an increase in photocurrent (J SC), photo-voltage (V OC), and, as a result, total efficiency (PCE). [Display omitted] In this study, a propeller-type molecule with a pyridine core (D) was designed and synthesized. Photophysical and electrochemical studies, along with theoretical DFT simulations, indicated that the molecule has suitable light absorption properties and frontier molecular orbital levels for usage as a sensitizer in dye-sensitized solar cells (DSSCs). Meanwhile, the standard dye Z-907 was chosen to investigate the effect of the synthesized molecule as a co-adsorbent dye on DSSCs. Intriguingly, when compared to the D and Z907 -based devices, the performance of the co-sensitized Z907 + D cell exhibited an increase in photocurrent (J SC), photo-voltage (V OC), and, as a result, total power conversion efficiency (PCE). [ABSTRACT FROM AUTHOR]

In the present investigation, ZnO/rGO nanocomposites were prepared using conventional solid-state reaction method. Raman, XRD, FTIR, UV–Vis, PL and FESEM characterization tools were used to analyze the synthesized materials. Raman analysis reveals the formation of rGO with prominent D and G-band peaks. XRD patterns confirm the crystalline and hexagonal wurtzite structure with P 6 3 mc space group of all the samples. Rietveld refinement demonstrates the size variation (33 nm–56 nm) and strain profile. FESEM micrographs of ZnO/rGO composites have established the formation of densely packed hexagonal nano-pebbles. UV–Vis and room temperature PL measurements indicate that the optical properties of ZnO and ZnO/rGO nanocomposites are affected by the rGO concentration. It also confirms a band gap shrinkage during nanocomposite preparation compared to the pure ZnO structure. Urbach energy is found to increase with increase in rGO content and the strength of electron-phonon interaction enhances. It also affects the PL emission in the UV region. FTIR spectra confirm the presence of different functional groups. Present investigation shows that ZnO/rGO materials are potential candidates for design and development of sensors for detecting gases. [Display omitted] • ZnO/rGO nanocomposites were prepared using conventional solid-state reaction method. • XRD, Raman, FTIR, and FESEM measurements confirm the ZnO/rGO nanocomposite formation. • UV-Vis and PL confirm the effect of rGO concentration on optical properties of synthesized ZnO/rGO. • Band gap shrinkage was observed during nanocomposite preparation. • FESEM confirms the formation of hexagonal nano-pebbles of ZnO/rGO composites, which may be useful for sensor applications. [ABSTRACT FROM AUTHOR]

• Screen printing of a 2D graphite/Cu supercapacitor with PVA-PVP polymer electrolyte. • A novel method introduced to deposit the electrolyte on the current collectors using a porous wet paper. • Overcame several disadvantages of conventional solid-state gel electrolytes. • Cyclic Voltammetry at various scan rates showed a specific capacitance of 24.12 F g−1. • Excellent flexibility with a maximum relative resistance change of 4.83% at a bending angle of 180°. A 2D supercapacitor with graphite/copper nanoparticle electrodes and a PVA-PVP polymer electrolyte was screen printed. A novel method to deposit the electrolyte on the current collectors using a porous wet paper has been described to overcome several disadvantages of conventional solid-state gel electrolytes. SEM imaging showed the ideal size of deep pores in the paper-based medium which assisted the electrolyte in storing charge and facilitated high conductivity and capacitance. Electrochemical analysis via Cyclic Voltammetry at various scan rates showed a specific capacitance of 24.12 F g−1. Cyclic stability and charge-discharge times were studied via galvanostatic charge-discharge cycles. The excellent flexibility of the device has been demonstrated by plotting the absolute and relative resistance change across the Cu electrodes at different bending angles with the maximum relative resistance change shown to be less than 5%. [ABSTRACT FROM AUTHOR]