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The purpose of this paper is to prepare new organic dyes and use them as sensitisers in dye-sensitised solar cells. These dyes were synthesised and purified and then characterised by analytical techniques. Spectrophotometric evaluations of the prepared dyes were carried out in solution and on a nano-anatase TiO₂ substrate to assess the possible changes in the status of the dyes in different environments. Finally, the photovoltaic properties were investigated in dye-sensitised solar cells.

So as to synthesise dyes, N-substituents carbazole were utilised as the fundamental electron donor group and cyanoacrylic acid or acrylic acid as electron acceptor anchoring groups. Purified dyes were dissolved in solution and coated on TiO₂ substrate. Finally, dye-sensitised solar cells were fabricated to determine the photovoltaic behaviour and conversion efficiency of each individual dye.

The results showed that the dyes form j-type aggregates on the nano TiO₂. The oxidation potential of synthesised carbazole dyes is > 0.2 V vs Fc/Fc+; hence, their high performance in dye-sensitised solar cells. Dye 3 exhibited 2.11 per cent of conversion efficiency in comparison to 2.89 per cent for the identical cells with Dye 9 containing cyanoacrylic acid which acted as the best acceptor group.

The novel dyes look as promising as highly light fast, efficient dyes for dye-sensitised solar cells.

Organic dye provides low cost and less hazardous materials for dye-sensitised solar cells.

A series of new organic dyes were synthesised as sensitisers for dye-sensitised solar cells for the first time.

The purpose of this paper is to introduce flexible dye-sensitized solar cells (FDSSCs).

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.

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.

In this study, the development of FDSSCs offers improved photovoltaic properties.

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.

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.

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-1Hbenz[de]isoquinolin-2(3H)-yl)benzenesulfonamides and 1,8-naphthalimide, were used.

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 Z_nO) substrate. DSSCs were prepared to determine the photovoltaic performance of each photosensitizer.

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 Z_nO are 3.21, 4.09 and 4.14 per cent, respectively.

In this study, the development of effect of assembling materials, offering improved photovoltaic properties.

Organic dye attracts more and more attention because of its low-cost, facile route synthesis and less-hazardous properties.

To the best of the authors’ knowledge, the effect of anchoring agent and nanostructure on DSSCs performance was investigated for the first time.

The purpose of this paper is to determine the development and knowledge flows of dye-sensitized solar cells (DSSCs) via the use of patent inventor database. Moreover, this study aims to explore patentees and inventors’ companies to help readers and practitioners to be able to understand the patentees, technology development and activities of knowledge flows from four countries. DSSCs, which are known as one of the key technologies of green energy, have been applied ever more widely to many different industries, and their use has quickly grown with a number of scientific publications and patent applications.

This paper was based on the US patent database collection of third-generation DSSCs in four typical countries such as USA, Japan, Germany and Taiwan to map the knowledge network of DSSC technology via the social network analysis method.

The knowledge network of 132 DSSC patents was explored. Among the four countries, Japan leads, with the main patent number being H01G009. This paper also indicates the knowledge flow situation of Japanese inventors of DSSCs. For example, patented inventors Wariishi and Koji (JP) served the Fuji Photo Film Co., Ltd. (JP) in 2002, and then in 2008, transferred to the Fuji Film Corporation (JP). This means that the knowledge of technology was transferred by people who moved to another company for a new job.

This study is based on US Patent and Trademark Office patent database to do exploration.

This study was expected to provide information for the industry, government and academia, so that they will understand the trajectory of the technology inventor, specialist cultivation and technology development in the DSSC industry.

This study provides useful information for the green energy industry, government and academia to understand the importance of the knowledge flows and future development of DSSC technology of the solar cell industry. Thereby, they can intensify industrial competence and innovation by externally collaborating in this field as well as to increase the industrial competence by reimbursing the funds from government and other research institutes.

The purpose of this paper is to improve the efficiency of dye-sensitized solar cells (DSSCs) which present promising low-cost alternative to the conventional silicon solar cells mainly due to comparatively low manufacturing cost, ease of fabrication and relatively good efficiency. One of the undesirable factor in DSSCs is the electron recombination process that takes place at the transparent conductive oxide/electrolyte interface, on the side of photoelectrode. To reduce this effect in the structure of the solar cell, a TiO₂ blocking layer (BL) by atomic layer deposition (ALD) was deposited.

Scanning electron microscope, Raman and UV-Vis spectroscopy were used to evaluate the influence of BL on the photovoltaic properties. Electrical parameters of manufactured DSSCs with and without BL were characterized by measurements of current-voltage characteristics under standard AM 1.5 radiation.

The TiO₂ BL prevents the physical contact of fluorine-doped tin oxide (FTO) and the electrolyte and leads to increase in the cell’s overall efficiency, from 5.15 to 6.18%. Higher density of the BL, together with larger contact area and improved adherence between the TiO₂ layer and FTO surface provide more electron pathways from TiO₂ to FTO which facilitates electron transfer.

This paper demonstrates that the introduction of a BL into the photovoltaic device structure is an important step in technology of DSSCs to improve its efficiency. Moreover, the ALD is a powerful technique which allows for the highly reproducible growth of pinhole-free thin films with excellent thickness accuracy and conformality at low temperature.

The purpose of this paper is to investigate the chemical, optical and photovoltaic properties of titanium dioxide/reduced graphene oxide (TiO₂/rGO) photoanodes immersed in natural Roselle and synthetic (N719) dyes for dye-sensitized solar cell (DSSC) application.

TiO₂ mixed with rGO were doctor-bladed on fluorine doped tin oxide (FTO) glass substrate. The chemical and optical properties of TiO₂/rGO photoanodes immersed in Roselle and N719 dyes were characterized using Fourier-transformed infrared (FTIR) and ultraviolet–visible (UV–vis) spectroscopies, respectively. The DSSC’s photovoltaic performances were tested using Visiontec Solar I-V tester at standard illumination of AM1.5 and irradiance level of 100 mW/cm².

The presence of anthocyanin dye from Roselle flower was detected at 604 nm and 718 nm. TiO₂/rGO+Roselle dye sample revealed the smallest energy gap of 0.17 eV for ease of electron movement from valence band to conduction band. The TiO₂/rGO-based DSSC fabricated with Roselle dye had a power conversion efficiency, ƞ of 0.743 per cent higher than TiO₂/rGO photoanode sensitized with N719 dye (0.334 per cent). The obtained J-V curves were analyzed by a single-diode model of Lambert W-function and manual optimization to determine the internal electrical parameters of the DSSC. The average and uncertainty values of J_sc and ƞ were evaluated at different R_sh range of 1362 Ω to 32 k Ω.

R_s values were kept constant during optimization work.

New ideality factor of TiO₂/rGO-based DSSC was re-determined around 0.9995.

The purpose of this paper is to study assembling parameters in dye-sensitised solar cells (DSSCs) performance. For this end, 3a,7a-dihydroxy-5ß-cholanic acid (cheno) are selected as anti-aggregation agent and two solutions, namely, tetrabutyl ammonium iodide and (PMII)IL used as electrolyte.

A series of organic dyes were selected using N-substituents carbazole as electron donor group and acrylic acid and cyanoacrylic acid as electron acceptor groups. Absorption properties of purified dyes were studied in solution and on photoelectrode substrate. DSSCs were prepared in the presence of anti-aggregation agent and different electrolyte to determine the photovoltaic performance of each dyes.

The results showed that all organic dyes form J-aggregation on the photoanode substrate in the absence of anti-aggregation agent and the amounts of aggregation were reduced in the presence of anti-aggregation agent. DSSCs were fabricated in the presence of anti-aggregation agent. The photovoltaic properties were improved using tetrabutyl ammonium iodide as electrolyte. The maximum power conversion efficiency was achieved for D12 in the presence of cheno and tetrabutyl ammonium iodide as anti-aggregation agent and electrolyte, respectively.

Organic dye attracts more and more attention due to low cost, facile route synthesis and less hazardous.

The effect of anti-aggregation agent and electrolyte on DSSCs performance was investigated for the first time.

Dye-sensitized solar cells consisting of tandem and hybrid structures are reported. It was proved that these new structures have a potential to harvest light with wide range of wavelength and increase open circuit voltage. In addition, modification of charge separation interfaces with organic molecules and dyes are discussed in terms of trap passivations which bring about high efficiency.

The purpose of this paper is to elucidate the aging effect in dye-sensitized solar cells (DSSCs) sealed with thermoplastic film and to compare it with unsealed DSSCs.

The paper presents the steps of the fabrication of standard DSSC, as well as the DSSC-sealing processes, by using thermoplastic film. Current-voltage characterization was performed to observe the changes in efficiency, fill factor, short circuit current density and open circuit voltage for both unsealed and sealed DSSCs for aging time up to 336 h.

The unsealed DSSC showed significant drop in efficiency from 4.26 to 2.42 per cent within the first 5.5 h of aging time because of the leakage and volatilization of the solvent in the electrolyte. On the other hand, the sealed DSSC exhibited a gradual improvement of efficiency from 4.16 to 4.73 per cent after the first 216 h of aging time. The initial efficiency increment can be ascribed to the improved adsorption of electrolyte into the titanium dioxide film because of the gradual desorption of excess dye from TiO2 with increasing aging time.

This paper demonstrates the importance of the proper sealing process for the long-term operation of DSSC.

Dye-sensitised solar cells (DSSCs) have attracted a great deal of interest. Dye molecules are key materials in DSSCs that produce electrons. This study reports on synthesis of the organic dyes and investigation their performance in DSSCs.

A series of new organic dyes were prepared using double rhodanine as the fundamental electron-acceptor group and aldehydes with varying substituents as the electron-donor groups. These dyes were first purified and then characterised by analytical techniques. DSSCs were fabricated to determine the photovoltaic behaviour and conversion efficiency of each individual dye.

Results demonstrated that all the dyes form j-type aggregates on the nano TiO₂. All dyes in DSSC structure show suitable power conversion efficiency, and Dye 5 due to presence of OCH₃ and OiPr presents maximum conversion efficiency.

In the search for high-efficiency organic dyes for DSSCs, development of new materials offering optimised photochemical stabilities as well as suitable optical and electrical properties is importance.

Organic dyes as photosensitisers are interesting due to low cost, relatively facile dye synthesis and capability of easy molecular tailoring.

A series of new organic metal-free dyes were prepared as sensitisers for DSSCs for the first time.