Dye-sensitized Solar Cell Module Research Articles

Demonstration of 12 Years Outdoor Working of Highly Durable Dye-Sensitized Solar Cell Modules Employing Hydrophobic Surface Passivation and Suppression of Biased Distribution of Iodine Ions

Dye-sensitized solar cells (DSCs) outperform conventional silicon solar cells in terms of weight and design flexibility. Therefore, besides standard rooftop installation, DSCs are suitable for new applications, including windows and walls. However, insufficient durability remains a critical issue, and outdoor working over 10 years is yet to be realized. In this study, we developed two approaches to improve the durability. The first involves hydrophobic surface passivation on the TiO2 surfaces by adopting alkylbenzimidazole (CnH2n+1BI) with long alkyl chains instead of the conventional additive (N-methylbenzimidazole) used for high open-circuit voltage in an ionic liquid-based electrolyte. The additive with a suitable alkyl-chain length (N-butylbenzimidazole and N-hexylbenzimidazole) notably improved the resistance against infiltrating water. The second approach refers to the DSC module arrangement. A unique problem of large-sized modules is that the I3– distribution often becomes biased over time, lowering the conversion efficiency. Horizontal module arrangements and/or the strip-shaped single cells in the modules solved this problem. By adopting these two approaches, we have demonstrated that the 10 cm × 11 cm-sized DSC modules have high durability to maintain 75% of their initial performance after the 12 year outdoor working test. This is the longest demonstrated lifetime for DSC modules outdoors.

Modified Poly(Vinyl Alcohol) Based Polymer Electrolyte for Dye Sensitized Solar Cells (DSSCs)

AbstractDue to increasing energy demand day by day, it must be necessary to have an alternate source of energy beside natural resources. Sun is the ultimate source of solar energy. So, from this solar energy, various types of solar cells are fabricated easily which are available in markets but these are somewhat costly. So, there is requirement of a low‐cost alternative to costly crystalline solar cells, which is fulfilled by dye sensitized solar cell (DSSC). Due to many potential properties like good ionic conductivity, thin film forming ability and many more, polymer electrolyte plays a vital role in improving the efficiency of DSSC which cannot be obtained by using volatile liquid electrolytes which are used earlier. The reliance of DSSCs on liquid electrolytes imposes a limit and restriction on the manufacture of DSSC modules. Liquid electrolyte faces many problems like corrosion, leakage, and evaporation. When the photoanode comes into touch with the volatilized redox‐electrolytes solution, the charge distribution at the semiconductor–electrolyte interface changes, resulting in photo corrosion on the photoelectrode. Furthermore, electron recombination at semiconductor–liquid electrolytes interfaces is discovered to cause performance losses. The concept of ionic conductivity observed in polymer materials when complexed with salt is a significant step forward in the development of DSSC devices.In this review, the fabrication of DSSC using polymer electrolyte, specifically PVA based solid polymer electrolyte is discussed. Here solid polymer electrolytes are of special interest due to thin film forming ability and overall good performance. Due to inherent properties like cost‐effectiveness, better tensile strength, and high hydrophilicity, PVA is chosen as a novel applicant for host polymer. The recent advancement of DSSC using modified PVA polymer electrolyte by incorporation of nanosized fillers, plasticizers, polymer blend, by the formation of conducting polymer electrolyte are discussed in detail. The improvement in ionic conductivity and enhanced efficiency of DSSC by using above mentioned factors are also discussed.

Employing Dye-Sensitized Solar Arrays and Synchronous Reluctance Motors to Improve the Total Cost and Energy Efficiency of Solar Water-Pumping Systems

In this work, a proposed high-efficiency and low-cost photovoltaic water-pumping system based on semitransparent dye-sensitized solar cells (DSSCs) is presented. DSSCs are low-cost third-generation photovoltaics that have gained a lot of interest as a promising alternative for silicon solar cells. DSSCs are fabricated at low cost and low temperature and present power conversions with high efficiency, exceeding 14%, thanks to high transparency, a variety of colors, and high efficiency, even in low light conditions. The DSSC modules used in this study were tested under different working conditions, and their characteristics were determined experimentally and simulated theoretically via MATLAB. A complete laboratory infrastructure is constructed to test the proposed photovoltaic water-pumping system based on the DSSC module array. The system contains a synchronous reluctance motor driving a water pump and feeding from the DSSCs via an inverter without DC–DC converters or batteries. The proposed system has many merits, such as high efficiency and low cost. The DSSCs’ maximum available power is obtained via a maximum power point tracking technique (perturb-and-observe). Moreover, a control system for driving the motor via the inverter was also implemented. The maximum torque per ampere strategy is also considered in the proposed control system to drive the motor efficiently using the inverter. Finally, experimental validation of the complete system via laboratory measurements is implemented.

Development of a Self-Sufficient LoRaWAN Sensor Node with Flexible and Glass Dye-Sensitized Solar Cell Modules Harvesting Energy from Diffuse Low-Intensity Solar Radiation

This paper aims to demonstrate the viability of energy harvesting for wide area wireless sensing systems based on dye-sensitized solar cells (DSSCs) under diffuse sunlight conditions, proving the feasibility of deploying autonomous sensor nodes even under unfavorable outdoor scenarios, such as during cloudy days, in the proximity of tall buildings, among the trees in a forest and during winter days in general. A flexible thin-film module and a glass thin-film module, both featuring an area smaller than an A4 sheet of paper, were initially characterized in diffuse solar light. Afterward, the protype sensor nodes were tested in a laboratory in two different working conditions, emulating outdoor sunlight in unfavorable lighting and weather to reconstruct a worst-case scenario. A Li-Po battery was employed as a power reserve for a long-range wide area network (LoRaWAN)-based sensor node that transmitted data every 8 h and every hour. To this end, an RFM95x LoRa module was used, while the node energy management was attained by exploiting a nano-power boost charger buck converter integrated circuit conceived for the nano-power harvesting from the light source and the managing of the battery charge and protection. A positive charge balance was demonstrated by monitoring the battery trend along two series of 6 and 9 days, thus allowing us to affirm that the system’s permanent energy self-sufficiency was guaranteed even in the worst-case lighting and weather scenario.

Review: Low Temperature Sintering of TiO2 for Dye Sensitized Solar Cells (DSSCs) Fabrication on Flexible Substrates

This article discusses the most recent developments in the manufacture of flexible dye-sensitized solar cells (DSSCs), with a focus on the use of flexible plastic substrates instead of rigid glass substrates. The temperature restriction of the substrate in generating TiO2 nanoparticles is a key problem for creating DSSCs on plastic substrates. Ball-milling, acid/water treatments, chemical vapor deposition, and electrophoretic deposition, as well as chemical and mechanical film processing methods such as chemical sintering, hydrothermal treatment, microwave irradiation, and various compression techniques, are all discussed here. It also includes research on novel flexible counter electrode manufacturing processes and recently produced new materials that are particularly beneficial for flexible DSSCs. Finally, the progress and possibilities of large-scale flexible DSSC module fabrication, as well as their endurance, are reviewed.

Bio and non‐bio materials‐based quasi‐solid state electrolytes in DSSC : A review

Dye-sensitized solar cells (DSSCs) are more attractive than silicon solar cells due to their low dependency on light intensity so that they can perform both indoor and outdoor with low-level lightings. DSSC's global revenue exceeded 16 million USD in 2014 for emerging portable charging, solar bags, and wireless keyboards. However, on-grid DSSC modules are still under R&D for massive commercialization to improve their long-term stability and safety issues due to the liquid electrolyte leakage. Therefore, quasi-solid-state electrolytes (QSE) have been proposed as a novel alternative to overcome the limitations stated above since 2001. Here, we deliver a short outline of the QSE properties, which are linked with the performance of DSSC in terms of different types of QSE structures: gel, hydrogel, and aerogel. Furthermore, these QSE structures are classified under bio and non-bio materials. Finally, the impact, outlook, and future prospects of QSE-DSSC are included as a conclusion in this review.

Research Insights and Challenges of Secondary School Energy Education: A Dye-Sensitized Solar Cells Case Study

The research achievements of a university chemistry lab regarding dye-sensitized solar cells (DSSCs) were transformed into a high school hands-on course by simplifying the experimental steps and equipment. Our research methodology was action research. We verified the DSSC course step by step. First, 10 members of a high school science study club helped to revise the course over a school semester. A questionnaire survey revealed that all students agreed that the course increased their understanding of DSSCs and solar cells. Second, 35 students were enrolled in a 10th-grade elective energy course to study the revised DSSC topics for 3 weeks. A five-point Likert scale was used to collect students’ feedback, and students reported looking forward to making their own high-performance DSSC modules (4.60) and stated that being able to make their own solar cell was a great accomplishment (4.49). Third, the course was implemented at a junior high school science camp, and the 37 participating students were all able to complete the hands-on experiment. In the questionnaire survey, the students expressed that they enjoyed learning about scientific principles through a hands-on approach (4.59). Fourth, most of the 12 schoolteachers who voluntarily participated in the DSSC workshop agreed that integrating DSSC activity into school courses would be conducive to multidisciplinary learning. This course could facilitate participants’ self-evaluations in science knowledge, experimental skills, learning motivations, and positive attitudes toward sustainability.

Controlled Photoanode Properties for Large-Area Efficient and Stable Dye-Sensitized Photovoltaic Modules.

Nowadays, a dye-sensitized solar cell (DSSC) attracts attention to its development widely due to its several advantages, such as simple processes, low costs, and flexibility. In this work, we demonstrate the difference in device structures between small size and large size cells (5 cm × 5 cm, 10 cm × 10 cm and 10 cm × 15 cm). The design of the photoanode and dye-sensitized process plays important roles in affecting the cell efficiency and stability. The effects of the TiO2 electrode, using TiCl4(aq) pretreatment and post-treatment processes, are also discussed, whereas, the open-circuit voltage (Voc), short-circuit current density (Jsc), and module efficiency are successfully improved. Furthermore, the effects on module performances by some factors, such as dye solution concentration, dye soaking temperature, and electrolyte injection method are also investigated. We have demonstrated that the output power of a 5 cm × 5 cm DSSC module increases from 86.2 mW to 93.7 mW, and the module efficiency achieves an outstanding performance of 9.79%. Furthermore, enlarging the DSSC modules to two sizes (10 cm × 10 cm and 10 cm × 15 cm) and comparing the performance with different module designs (C-DSSC and S-DSSC) also provides the specific application of polymer sealing and preparing high-efficiency large-area DSSC modules.

Development of Highly Transparent Dye-Sensitized Solar Cell Module

Dye-sensitized solar cell (DSSC) processes transparent, colorful, and flexible architectures that have attracted significant interest in terms of newly emerging see-through photovoltaic windows. In this study, we developed transparent TiO2 and Pt counter electrodes to fabricate DSSC module with high transparency and power conversion efficiency (PCE). The TiO2 nanoparticles having sizes from 14 to 30 nm were prepared by the variation of the TiO2 precursor content and by controlling the synthetic conditions for highly transparent pastes. The transmittance of all TiO2 films were superior to those prepared by commercial pastes with the identical thickness. In addition, we prepared paste of TiO2 blocking layer by controlling the Ti precursor/vehicle. The as-prepared TiO2 blocking layer with screen-printing process exhibited a transmittance of ca. 77.59%, which is superior than those prepared by the conventional spin-coating (74.79%) and dip- coating (71.14%) of the precursors. Furthermore, highly transparent and screen-printable Pt paste for counter electrode was also developed by controlling the Pt precursor. The transmittance of as-prepared Pt counter electrode (75.3%) was higher than the conventional one with spin-coating method (69.3%). Then, DSSC module(Z-type) with the active area of 100.8 cm2 that have Red, Green and Blue colors(N719,N749,SGT-140) showed a PCE of ca. 7.0 %, 5.5%, 4.2% with Isc of 0.1A, 0.08A, 0.1A Voc of 12.3 V, 9.6V, 8.4V FF of 67.8%, 72.2%, 52% and the transmittance reached up to 30%.

Preparation and Characterization of Novel Polymer-Based Gel Electrolyte for Dye-Sensitized Solar Cells Based on poly(vinylidene fluoride-co-hexafluoropropylene) and poly(acrylonitrile-co-butadiene) or poly(dimethylsiloxane) bis(3-aminopropyl) Copolymers.

Polymer gel electrolytes based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(acrylonitrile-co-butadiene) (PAB) or poly(dimethylsiloxane) bis(3-aminopropyl)-terminated (PDES-bAP) copolymers were prepared and investigated in dye-sensitized solar cells (DSSCs). Selected optical and electrochemical properties of all compositions with various ratio from 9:1 to 6:4 were investigated towards DSSC applications. The highest value of power conversion efficiency equal to 5.07% was found for DSSCs containing a PVDF-HPF:PAB (9:1) gel electrolyte. Compositions of electrolytes were additionally tested by electrochemical impedance spectroscopy. The influence of the ratio and type of polymers used as an additive to PVDF-HPF on absorption wavelengths, energy gap, and Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) levels were investigated. Individual components of DSSCs, such as the TiO2 layer and platinum nanoparticles, were imaged by scanning electron microscope. Finally, a DSSC module with six electrically separated solar cells with a 7 × 80 mm2 active area was constructed based on gel electrolytes and tested.

Hierarchically SrTiO3@TiO2@Fe2O3 nanorod heterostructures for enhanced photoelectrochemical water splitting

In this particular work, the fabrication of SrTiO3@TiO2@ Fe2O3 nanorod heterostructure has been demonstrated via hydrothermal growth of SrTiO3 cubic on the rutile TiO2 nanorod as a template and later sensitized with Fe2O3 for photocatalytic solar hydrogen production in a tandem photoelectrochemical cell and dye-sensitized solar cell (DSSC) module. The photocatalytic solar hydrogen production of this heterostructure was optimized by controlling the amount of Sr and Fe on the surface of photocatalyst. The details of the influencing parameters on the physicochemical and photoelectrochemical properties are discussed. It was found that the morphology and quality of the fabricated materials were greatly manipulated by the concentration of Sr and Fe. The optimized 0.025 M SrTiO3@TiO2@ Fe2O3 heterostructure exhibited a higher photoconversion efficiency with a long electron lifetime, low charge transfer resistance and large donor density at the electrode and electrolyte interface. This composite has significantly improved the photocatalytic hydrogen production, yielding 716 μmol/cm2 of maximum accumulative hydrogen. These results show that morphology rendering and manipulation of energy band alignment is crucial in creating efficient heterojunctions for excellent contributions in photocatalytic applications.

A transparent and Pt-free all-carbon nanocomposite counter electrode catalyst for efficient dye sensitized solar cells

Recently, substantial focus has made in the development of cost effective Pt-free dye sensitized solar cells (DSSCs). In this article we report a potential, Pt-free, carbon based nanocomposite as counter electrode catalyst for dye sensitized solar cells. Graphene oxide (GO) was made into reduced graphene oxide (SSrGO) by irradiating with light (Xe source). Suspension of SSrGO in DMF was spray coated onto fluorine doped tin oxide (FTO) coated glass substrate, followed by spray coat of single walled carbon nanohorns (SWCNH) suspension in DMF. SSrGO and SWCNH coated FTO glass substrate was investigated as an effective Pt-free composite counter electrode (CE) for DSSC and also showed the comparable catalytic activity with Pt. The test cell reveals power conversion efficiency (PCE) of 8.27%, whereas the DSSC module exhibited a PCE of 5.18%. By using the fabricated DSSC module, an electric motor (15 mW) was operated both in indoor and outdoor light conditions. The procedures followed in this work pave a way for the easy fabrication of composite CE towards transparent DSSC modules and further the integration of the DSSC module with the standard Si solar cell is of great potential for various real-time application.

Penilaian Kitaran Hayat Sel Suria Terpeka Pewarna di Malaysia

Solar energy is the most abundant nature resources on earth which easily exploitable, clean, long lasting and dependable which make it is desirable to generate electricity compared to other energy resources. However, conventional solar photovoltaic (PV) technologies such as silicon and thin film solar cells may provide significant environmental impacts over their life cycle due to complicated production process of these PV technologies. This make numerous scientists looking forward on the new emerging solar cells including dye sensitized solar cell (DSSC). Thus, the objective of this research is to analyse a comprehensive environmental impact assessment through life cycle assessment (LCA) from cradle-to-gate approach of this technology in Malaysia. Two environmental indicators were evaluated such as cumulative energy demand (CED) that affect the energy payback time (EPBT), and greenhouse gas (GHG) emissions. The results highlight that DSSC module has EPBT of 3.49 years, CED of 1190.29 MJ/m2 and GHG emissions of 262.38 gCO2eq/kWh which were slightly higher compared to other researchers. Higher energy consumption in module fabrication and panel manufacturing process, lower conversion efficiency (ŋ) and solar irradiation (IR), and used of FTO glass substrate were recognized as main contributors to the results.

Fabrication of Dye-Sensitized Solar Cells Using Zinc Oxide Nanorod-Modified Titanium Dioxide Photoanode

This study fabricated a novel dye-sensitized solar cell with ZnO nanorod-modified TiO2 photoanode. Aluminum-doped zinc oxide was sputtered onto a fluorine doped tin oxide glass to generate a seed crystal layer. Hydrothermal synthesis was used to prepare zinc oxide (ZnO) nanorods, which were sprayed with titanium dioxide (TiO2) to form a photoanode. This new structure increased dye absorption in the photoanode. Current situation was determined by ultraviolet-visible spectroscopy. An increase in the ZnO film's ability to absorb dye increased the cell's short circuit current density, raising the photovoltaic conversion efficiency from 3.71% to 4.87%. The dye-sensitized solar cell module was testsed, 2 in series and 2 in parallel, and a stability analysis was performed.

CNT fibres as dual counter-electrode/current-collector in highly efficient and stable dye-sensitized solar cells

This work demonstrates that carbon nanotube (CNT) fiber electrodes consisting of a mesoporous and crystalline network of few-layer CNTs can be used as free-standing, unipolar, and dual counter-electrode (CE)/current-collectors in highly efficient and stable planar dye-sensitized solar cells (DSSCs). After device optimization, particularly in terms of photoanode thickness, the solar energy conversion efficiency reached 8.8%, which is comparable to devices with platinum CE (8.7%). Through study of symmetric cells using electrochemical impedance spectroscopy (EIS) measurements, this work discloses the first clear identification of the different processes involved in the use of CNTf electrodes as CE, namely bulk ion diffusion, ion diffusion inside the mesoporous electrode, and charge transfer at the CNT surface. These results provide clear directors for a further understanding of the fundamental catalytic properties of CNTf fibers towards improving their photoelectrochemical features. Finally, we assemble new device architectures, namely i) a free-standing CNT-CEs (unipolar electrode) device with two photoanodes facing each other to circumvent the lack of transparency of CNTs without losing performance, and ii) large-area solar cells (>10 cm2) with 10 devices interconnected in parallel along 1 m continuous CNTf-CE, featuring efficiencies comparable to the-state-of-the-art carbon-based DSSC modules.

Effect of Reverse Bias on Dye-Sensitized Technology: Lessons for Application in PV-Integrated Textile Fabric Designs Useable in Wajir, Vihiga, Kitui and Kajiado Counties in Kenya

This paper reports on the effect of reverse bias (RB) on dye-sensitized solar cells (DSSCs) that were investigated outdoor in Wajir (1o44’50’’ North, 40o 4’ 8’’ East), Vihiga (35o0’ East, 0o15’ North), Kitui (3o 0’ South, 37o 50’ East) and Kajiado (360o 5’ East, 30o 0’ South) in Kenya. The DSSCs’ J-V characteristics, namely, Voc, Jsc, FF and ?, were studied under varied RB potentials. This was achieved through partial, as well as complete shading of the DSSCs during their operation in the study sites, using a thick piece of black cloth, and measuring the obtaining J-V characteristics. Findings of the study reveal that subjecting the DSSC module that was investigated in Wajir to RB of between 1V and 4V triggered between 25.53% and 23.53% drop in the module’s efficiency (?), followed by its total breakdown thereafter. The modules studied in Vihiga, Kitui and Kajiado exhibited a similar trend, but with variations in ? under the different RB regimes. The DSSCs’ breakdown under RB regimes of over half their voltage ratings could be attributed to the damaging of their dye constituents. These findings are important for context-informed DSSC dye choices, as well as DSSC-integrated designs that appeal to local cultural textile fabrics, like shawls, kanzu (long robes) and light coats that women and men dress in, respectively, in Wajir, and blankets that both men and women wrap around their shoulders in Kajiado, as well as in local architectures. The findings underscore the existence of vast prospects for localized industries that innovate in DSSC-integrated designs for local espousal. They could form foundations for programs that mentor people, especially children and youths at local levels to engage in climate change-mitigating enterprises.

Power performance analysis of a transparent DSSC BIPV window based on 2 year measurement data in a full-scale mock-up

Among transparent solar cells or modules, the DSSC (Dye-sensitized solar cell) has a relatively low production cost compared to silicon-based solar cells and provides a range of colors for building design. On the other hand, its commercialization has been limited by the low power generation efficiency and durability. Few studies have examined the power generation performance of a full scale DSSC module applied to actual buildings. In this study, a long-term performance test was conducted on vertical and inclined DSSC BIPV (Building Integrated Photovoltaic) windows applied to a full-scale mock-up facility to verify the power performance and power characteristics of transparent DSSC BIPV glazing under actual conditions over a 2 year period.The DSSC module was fabricated by the serial connection of nine 2.26Wp transparent DSSC sub-modules. The multi-layered DSSC BIPV glazing, which was composed of a “DSSC module (9mm)” + “air space (12 mm)” + “clear glass (5mm)” was joined to the curtain wall frame of the test cell facility.The unit size of the DSSC BIPV glazing was 0.975 m (W) × 0.965 m (H) and its maximum capacity was 20.34Wp. The size of the test cell facility was 3 m (W) × 3 m (H) × 9 m (D). The building is a container type insulated with 100 mm urethane foam. Four and two DSSC BIPV windows were installed on the vertical south wall and on the 30° sloped roof, respectively. Through the monitoring system, the power performance data of each DSSC BIPV windows and meteorological data were analyzed over a two year period (from 1st Jan. 2015 to 31st Dec. 2016).The 2 year data showed that the average daily power yield for each month of the vertical DSSC BIPV window ranged from 1.75 to 3.93 kWh/kWp·day (average 2.53 kWh/kWp·day), whereas that of the 30° sloped DSSC BIPV window ranged from 2.16 to 5.34 kWh/kWp·day (average 3.60 kWh/kWp·day).The operating power efficiency of the vertical DSSC BIPV window ranged from 2.65 to 4.14% with an average of 3.40%, whereas that of the sloped DSSC BIPV window was in the range of 2.64–3.63% with a mean of 3.01%. The power generation efficiency of the vertical plane BIPV window was higher than the sloped BIPV window. In contrast to the average daily power yield, the power efficiency of the vertical window was higher than that of the sloped window, which may be due to the higher efficiency of the DSSCs under overcast conditions. This is consistent with the power performance of the DSSC BIPV windows according to the sky conditions, which showed an increase in power efficiency with increasing cloud cover or decreasing solar intensity.

Scale-Up of the Electrodeposition of ZnO/Eosin Y Hybrid Thin Films for the Fabrication of Flexible Dye-Sensitized Solar Cell Modules.

The low-temperature fabrication of flexible ZnO photo-anodes for dye-sensitized solar cells (DSSCs) by templated electrochemical deposition of films was performed in an enlarged and technical simplified deposition setup to demonstrate the feasibility of the scale-up of the deposition process. After extraction of eosin Y (EY) from the initially deposited ZnO/EY hybrid films, mesoporous ZnO films with an area of about 40 cm2 were reproducibly obtained on fluorine doped tin oxide (FTO)-glass as well as flexible indium tin oxide (ITO)–polyethylenterephthalate (PET) substrates. With a film thickness of up to 9 µm and a high specific surface area of up to about 77 m2·cm−3 the ZnO films on the flexible substrates show suitable properties for DSSCs. Operative flexible DSSC modules proved the suitability of the ZnO films for use as DSSC photo-anodes. Under a low light intensity of about 0.007 sun these modules achieved decent performance parameters with conversion efficiencies of up to 2.58%. With rising light intensity the performance parameters deteriorated, leading to conversion efficiencies below 1% at light intensities above 0.5 sun. The poor performance of the modules under high light intensities can be attributed to their high series resistances.

Cosensitization of Structurally Simple Porphyrin and Anthracene-Based Dye for Dye-Sensitized Solar Cells.

Since their introduction, dye-sensitized solar cells (DSCs) have achieved huge success at a laboratory level. Recently, research is concentrated to visualize large DSC modules at the commercial platform. In that aspect, we have tested structurally simple porphyrin-based dye SK6 and anthracene-based dye CW10 for DSCs application under simulated 1 sun (AM 1.5G) and indoor light sources. These two dyes can be easily synthesized and yet are efficient with cell performances of ca. 5.42% and ca. 5.75% (without coadsorbent/additive) for SK6 and CW10, respectively, under AM 1.5G illumination. The power conversion efficiency (PCE) of SK6 reported in this work is the highest ever reported; this is achieved by optimizing the adsorption of SK6 on TiO2 photoanode using the most suitable solvent and immersion period. Cosensitization of SK6 with CW10 on TiO2 surface has boosted cell performance further and achieved PCE of ca. 6.31% under AM 1.5G illumination. Charge-transfer properties of individual and cosensitized devices at TiO2/dye/electrolyte interface were examined via electrochemical impedance spectroscopy. To understand the cell performances under ambient light conditions, we soaked individual and cosensitized devices under T5 and light-emitting diode light sources in the range of 300-6000 lx. The PCE of ca. 22.91% under T5 light (6000 lx) with JSC = 0.883 mA cm-2, VOC = 0.646 V, and FF = 0.749 was noted for the cosensitized device, which equals a power output of 426 μW cm-2. These results reveal that DSCs made of structurally simple dyes performed efficiently under both 1 sun (AM 1.5G) and indoor light conditions, which is undoubtedly a significant achievement when it comes to a choice of commercial application.

Performance of 7-cells Dye Sensitized Solar Module in Z-type Series Interconnection

Dye sensitized solar cells (DSSC) is becoming attractive research topic as third generation solar cells technology since it provides clean energy and low cost fabrication. In this study, DSSC was fabricated into module scale, which is important for practical applications. The module was prepared in sandwich structure consisting of TiO2 working electrode and Pt counter electrode on conductive substrate with an area of 100 mm x 100 mm, which was distributed into seven active cells. TiO2 paste was deposited on FTO glass as working electrode with a size of 10 mm x 98 mm per unit cell by screen printing method. Each cell was connected in Z-type series that able to produce high voltage. I − V measurement was applied in two methods consisting of laboratory testing using sun simulator under 500 W/m2 of illumination and outdoor testing using a digital multimeter under direct sunlight. The result shows that DSSC module has photoconversion efficiency of 1.08% and 1.17% for laboratory and outdoor testing, respectively. The module was also tested in three different times to monitor its stability performance.