K.F. Chan; H.N. Lim; N.M. Huang; Ahmad H.
Abstract
This paper reviews the recent development of ruthenium complex sensitizers, organic sensitizers, and co-sensitizers for dye-sensitized solar cell (DSSC) applications. The development of ruthenium sensitizers has progressed from thiocyanate (NCS) ligands containing bipyridyl, terpyridyl, quarterpyridyl, ...
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This paper reviews the recent development of ruthenium complex sensitizers, organic sensitizers, and co-sensitizers for dye-sensitized solar cell (DSSC) applications. The development of ruthenium sensitizers has progressed from thiocyanate (NCS) ligands containing bipyridyl, terpyridyl, quarterpyridyl, and cyclometalated ruthenium sensitizers to NCS-free analogs. The integration of organic moieties and ruthenium complex ancillary ligands into a single structure entity was also achieved in the DSSC industry. The development of organic sensitizers as an alternative to ruthenium-based sensitizers was also discussed according to their functional segment: donor, acceptor, and π-spacer. The modification of donor groups has been focused on introducing ancillary groups to increase the molar extinction coefficient and electron recombination resistance. Anchoring groups other than cyanoacrylic acids have been developed to improve the anchoring ability of organic sensitizers while maintaining their light-harvesting properties. A study was performed on π-spacers modified with different conjugation lengths and conjugated side chains in order to enhance the charge transfer within organic sensitizers. Co-sensitization systems, including metal-metal, metal-organic, and organic-organic systems with stepwise and “cocktail” co-sensitization methods will be discussed in this review.

Sultan A. Al-horaibi; S.T. Gaikwad; Anjali S. Rajbhoj
Abstract
The requirement for energy is ever increasing in the past few years due to the need for the innovation of clean energy and eco-friendly technologies. Symmetric and asymmetric squaraine dyes have received increasing attention and great potential for use as squaraine sensitizers for application in dye-sensitized ...
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The requirement for energy is ever increasing in the past few years due to the need for the innovation of clean energy and eco-friendly technologies. Symmetric and asymmetric squaraine dyes have received increasing attention and great potential for use as squaraine sensitizers for application in dye-sensitized solar cells (DSSC). This review article gives a synopsis of the advancements on squaraine sensitizers in the domain of DSSC and the chance used to enhance their overall energy conversion efficiency. Specifically, the primary factors in charge of the low values of open-circuit voltage (Voc), short-circuit photocurrent (Jsc) and fill factor (FF) are debated in detail. Future orientations in research and expanded absorptions of near infrared region (NIR) by development of organic substances and their applications are suggested from a personal point of view.

Sultan A. Al-horaibi; S.T. Gaikwad; Anjali S. Rajbhoj
Abstract
Squaraine dyes (SQ) have acquired sufficiently great attention as dye-sensitized solar cell (DSSCs) materials. In the present study, we have synthesized and characterized of two novel symmetrical sensitizers dyes for dye-sensitized solar cells which contain electron withdrawing (−COOH) group with ...
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Squaraine dyes (SQ) have acquired sufficiently great attention as dye-sensitized solar cell (DSSCs) materials. In the present study, we have synthesized and characterized of two novel symmetrical sensitizers dyes for dye-sensitized solar cells which contain electron withdrawing (−COOH) group with long alkyl ester chain (SQ1) and another without encoring group (SQ2). We have investigated the structural, electronic, photo-electrochemical, and charge transport properties of two SQ1& SQ2 indole-based squaraine dyes. The ground state geometry has been computed by applying density functional theory (DFT). The excitation energy and the oscillator strength were calculated by using time-dependent (DFT-TD) at DFT/B3LYP/6-31G** level of theory. We have focused and study on the frontier molecular orbitals (HOMO and LUMO), electron injection (ΔG inject ), light harvesting efficiency (LHE), open-circuit voltage (Voc), relative electron injection (ΔGr inject ), and short-circuit current density (Jsc). The effect of-COOH as (acceptor) and -OCH3 (donor) groups on SQ1 and SQ2 were investigated. The factors affecting, ΔG inject , LHE, Voc and Jsc revealed that SQ1 would be more favourable to enhance the performance of DSSCs. The theoretical calculations and absorbance results show that the electron density of LUMO of SQ1 is delocalized in the whole chromophore, leading to strong electronic coupling between SQ1 and TiO2 surface. So, the SQ1 sensitized solar cells exhibit better photovoltaic performance.

Glécia V. S. Luz; Wang. S. Hui; Renata C. Roncoleta; Pedro H. O. Nogueira; Lourdes M. Brasil; Pilar Hidalgo
Abstract
This research aimed to build hybrid solar cells, based on Grätzel method. We used the Polyethylene Terephthalate (PET) polymer as a substrate containing a layer of Indium Tin Oxide (ITO). Films of ZnO nanoparticles (ZnO NPs) synthesized by Pechini Method, and four different dyes were tested: Congo ...
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This research aimed to build hybrid solar cells, based on Grätzel method. We used the Polyethylene Terephthalate (PET) polymer as a substrate containing a layer of Indium Tin Oxide (ITO). Films of ZnO nanoparticles (ZnO NPs) synthesized by Pechini Method, and four different dyes were tested: Congo Red (CR), Bromocresol Green (BG), Acridine Orange (AO) and a Ruthenium Complex (RC). ZnO NPs were analyzed by XRD, which generated peaks corresponding to hexagonal wurtzite crystalline structure. We also conducted analysis by UV–Vis. Spectroscopy and Transmission Electron Microscope (TEM). Rietveld analysis determined the crystal size of 115.23 ± 28.16 nm. The deposition of ZnO and dye thin films were made through spin-coating. The electrical properties of the formed films were characterized with Van der Pawn method. Efficiency in converting light in electricity under an OSRAM 20W light bulb was tested after the devices were built. The smaller sheet resistance results were obtained for material containing: PET/ITO/ZnO/CR and PET/ITO/ZnO/AO. As expected, the best open-circuit voltage (Voc) results reached were 64 and 73 mV to CR and AO, respectively. Therefore, the results demonstrated satisfactory interaction between the ZnO-Dye-Electrolyte layers.

Yashwant Pandit; G. T. Harini; Deepa Landage; Chetan J. Bhongale
Abstract
The formation of mesoscopic titania is done by templated mechanism in which the films are prepared by co-assembly of titania precursor species and complexing agent acetyl acetone (acac) and an amphiphilic structure-directing agent, Pluronic F127 (a triblock copolymer). Thinner films of titania having ...
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The formation of mesoscopic titania is done by templated mechanism in which the films are prepared by co-assembly of titania precursor species and complexing agent acetyl acetone (acac) and an amphiphilic structure-directing agent, Pluronic F127 (a triblock copolymer). Thinner films of titania having well organized mesoscopic structure were prepared by doctor-blading method. These films were characterized by SEM, TEM, XRD, etc. UV-Vis absorption studies showed good dye intake in very thin mesoscopic titania layers. Prototype photovoltaic device fabricated utilizing the mesoscopic titania films showed reasonable power conversion efficiency and fill factor (FF). The device with mesoscopic TiO2 layer with thickness as low as 300 nm gave solar cell efficiency 0.31% and FF of 50.2%. This proves the utility of very thin layer of mesoscopic titania fabricated by doctor-blading technique. Such a thin layer may be useful in perovskite solar cells as well. Application of versatile dye molecules, polymers with suitable anchoring functionality could lead to desired high-performance photovoltaic devices.

Amrik Singh; Devendra Mohan; Dharmavir S. Ahlawat; Sandeep Chopra
Abstract
Indium Tin Oxide (ITO) coated glass acts as a substrate for photoanode of Dye Sensitized Solar Cells (DSSCs). The ITO substrate was irradiated by oxygen ion with different fluence (1x10 11 and 1x10 12 ions/cm 2 ) at 100 MeV energy. The TiO2 films were also subjected with same ion irradiation at 100 MeV ...
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Indium Tin Oxide (ITO) coated glass acts as a substrate for photoanode of Dye Sensitized Solar Cells (DSSCs). The ITO substrate was irradiated by oxygen ion with different fluence (1x10 11 and 1x10 12 ions/cm 2 ) at 100 MeV energy. The TiO2 films were also subjected with same ion irradiation at 100 MeV of energy with fluence of 1x10 11 ions/cm 2 and 5x10 12 ions/cm 2 . At 100 MeV energy of O 7+ ion the electronic and nuclear energy loss for TiO2 film have been measured 7.38x10 -1 KeV/nm and 3.8x10 -4 KeV/nm respectively. However, the electronic and nuclear energy loss of ion irradiation for ITO substrate were 7.4x10 -1 KeV/nm and 4.06x10 -4 KeV/nm respectively. Similarly longitudinal/ lateral straggling of ITO and TiO2 have been found 3.87 μm/2.50 µm and 3.62 µm/1.14 μm respectively. Further, the structural and optical properties of these samples were monitored by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible spectroscopy. It was found that oxygen ion (O 7+ ) irradiation of ITO film has slightly changed the crystallinity and transmission decreases. Furthermore, the particle size of TiO2 thin film has been obtained 80 nm corresponding to (101) plane of XRD pattern. In the case of ITO thin film the crystallite size and band gap changes from 62.35 nm to 53.89 nm and 3.993 eV to 3.971 eV at 1x10 12 ions/cm 2 respectively. Moreover this paper is also reporting that irradiation by swift heavy ion has changed the transmission of the ITO films, and its values decreases as compared to pristine (ITO) which degraded the performance of DSSC. Consequently, a very small value of absorbance is reported for ITO film. However, the absorbance of TiO2 film has found to increase with irradiation of oxygen ion at fluence of 1x10 12 ions/cm 2 and decreased at 5x10 12 ions/cm 2 . It is also confirmed that the absorbance of TiO2 film and TiO2/ITO photoanode increases with irradiation of oxygen ion at fluence of 1x10 12 ions/cm 2 and decreased at 5x10 12 ions/cm 2 . The band gap values of TiO2 thin film were obtained to have a change from 3.37 eV (for pristine) to 3.44 eV at 5x10 12 ions/cm 2 . But the decrease in band gap is also found 3.17 eV at fluence of 1x10 12 ions/cm 2 . However, N719 dye loaded O 7+ (1x10 12 ions/cm 2 ) irradiated TiO2 film show high absorption as compared to other samples. Thus the dose of O 7+ irradiation at fluence 1x10 12 ions/cm 2 may fabricate more efficient DSSC and consequently future prospective of such type of photoanode materials for dye sensitized solar cells seems to be bright.
Chaitanya Bathina; Krishnaiah Mokurala; Prasanth Ravindran; Parag Bhargava; Sudhanshu Mallick
Abstract
Use of Pt and fluorine-doped tin oxide (FTO) substrate together as a counter electrode (CE) significantly increases the fabrication cost of dye-sensitized solar cells (DSSCs). In the present study, we report the cost effective Pt and FTO-free (Cu2ZnSnS4 (CZTS) nanoparticle coated on W substrate) CE for ...
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Use of Pt and fluorine-doped tin oxide (FTO) substrate together as a counter electrode (CE) significantly increases the fabrication cost of dye-sensitized solar cells (DSSCs). In the present study, we report the cost effective Pt and FTO-free (Cu2ZnSnS4 (CZTS) nanoparticle coated on W substrate) CE for ZnO-based DSSCs. Phase purity, the morphology and elemental composition of synthesized ZnO, CZTS nanoparticles and films were confirmed by physical characteristics such as XRD, FEG-TEM, and FEG-SEM respectively. Cyclic voltammetry study confirmed electrochemical catalytic activity of CZTS films. DSSCs fabricated with CZTS film on W and FTO substrate as CE exhibited efficiencies of 2% and 2.8%, respectively. Conventionally used Pt-based CE demonstrated an efficiency of 3.8 %.
Oman Zuas; Harry Budiman; Nuryatini Hamim
Abstract
The ZnO nanoparticles (ZnO NPs) were synthesized by co-precipitating method followed by calcining at 500 o C for 4 h. The characterization data show that the synthesized ZnO NPs were present in hexagonal wurtzite structure and space group P63mc with high purity and good crystalline nature. The synthesized ...
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The ZnO nanoparticles (ZnO NPs) were synthesized by co-precipitating method followed by calcining at 500 o C for 4 h. The characterization data show that the synthesized ZnO NPs were present in hexagonal wurtzite structure and space group P63mc with high purity and good crystalline nature. The synthesized ZnO NPs were tested for decolorization of congo red (CR) dye under microwave irradiation using microwave induced catalytic (MIC) method. The investigation results showed that the microwave induced ZnO NPs process could effectively decolorize the CR dye with the efficiency approaches 90.63% in a short contact time under given condition of 10 mg/l CR dye, 300 watt of microwave power, 3 min of contact time, and 3 g/l of catalyst dosage. Since the microwave-induced catalytic process in this study is noticeable, the microwave technology coupled with ZnO NPs as catalyst may have synergistic effects on the decolorization of CR dye giving high degradation ratio in short reaction time. Therefore, the microwave technology can be used as an alternative option to enhance the catalytic activity of metal nanoparticles dealing with removal of various industrial dyes containing wastewater.