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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.

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.

Influenced by the constantly changing manufacturing environment, no single dispatching rule (SDR) can consistently obtain better scheduling results than other rules for the dynamic job-shop scheduling problem (DJSP). Although the dynamic SDR selection classifier (DSSC) mined by traditional data-mining-based scheduling method has shown some improvement in comparison to an SDR, the enhancement is not significant since the rule selected by DSSC is still an SDR.

This paper presents a novel data-mining-based scheduling method for the DJSP with machine failure aiming at minimizing the makespan. Firstly, a scheduling priority relation model (SPRM) is constructed to determine the appropriate priority relation between two operations based on the production system state and the difference between their priority values calculated using multiple SDRs. Subsequently, a training sample acquisition mechanism based on the optimal scheduling schemes is proposed to acquire training samples for the SPRM. Furthermore, feature selection and machine learning are conducted using the genetic algorithm and extreme learning machine to mine the SPRM.

Results from numerical experiments demonstrate that the SPRM, mined by the proposed method, not only achieves better scheduling results in most manufacturing environments but also maintains a higher level of stability in diverse manufacturing environments than an SDR and the DSSC.

This paper constructs a SPRM and mines it based on data mining technologies to obtain better results than an SDR and the DSSC in various manufacturing environments.

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 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 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.

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.

This paper aims to provide details of recent energy harvesting developments.

Following an introduction, this paper first considers mechanical and biomechanical energy harvesting developments. It then discusses hybrid harvesting technologies and self-powered sensors and concludes with a brief discussion.

Energy harvesting is the topic of a major research effort and growing commercial activities. Several advanced technologies are being used to develop sophisticated devices to harvest individual or combined energy sources. These developments are expected to play a central role in many emerging sensor markets.

This paper provides technical details of a selection of recently reported energy harvesting developments.