Highly Efficient Dye-sensitized Solar Cells

2011 ◽  
Vol 1327 ◽  
Author(s):  
Liyuan Han ◽  
Ashraful Islam
Keyword(s):  
Solar Cells ◽  
Equivalent Circuit ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Equivalent Circuit Model ◽  
Alkyl Substituent ◽  
Circuit Model ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

ABSTRACTThe present paper discusses the principle of dye-sensitized solar cells (DSCs) in terms of equivalent circuit model and the key issues to improve the device efficiency. Equivalent circuit model is proposed following analysis by electrochemical impedance spectroscopy of the voltage dependence of the internal resistance elements of DSCs. The influence of these elements upon cell performance in areas such as short circuit current density (Jsc), open circuit voltage (Voc), and fill factor (FF) was examined based on the equivalent circuit. Efficient sensitization of nanocrystalline TiO2 film was observed across the whole visible range and into the near-IR region as far as 1000 nm with a new panchromatic substituted β-diketonato Ru(II)-terpyridine dye (HIG1). Introduction of bulky alkyl substituent group in a β-diketonato Ru(II)-terpyridine dye (A3) suppress aggregate formation result in an improved performance of DSCs and the performance is independent of the additive added during the dye adsorption process. The haze factor of TiO2 electrodes is a useful index when fabricating light-confined TiO2 electrodes to improve Jsc. It was demonstrated that blocking of bare TiO2 surface with small molecules is an effective way of suppress interfacial charge recombination at the TiO2-dye/electrolyte interface and of improving shunt resistance and Voc. FF was also improved by reduction of the internal series resistance, which is composed of the following three elements: the redox reaction resistance at the platinum counter electrode, the resistance of carrier transport by ions in the electrolyte, and resistance due to the sheet resistance of the transparent conducting oxide. Finally, the highest efficiency scores of 10.4% and 11.1% (aperture illumination area 1.004cm2 and 0.219cm2, respectively) were confirmed by a public test center.

scholarly journals There Is a Future for N-Heterocyclic Carbene Iron(II) Dyes in Dye-Sensitized Solar Cells: Improving Performance through Changes in the Electrolyte

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4181 ◽  
Author(s):  
Mariia Karpacheva ◽  
Vanessa Wyss ◽  
Catherine E. Housecroft ◽  
Edwin C. Constable
Keyword(s):  
Solar Cells ◽  
Alkyl Chain ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Ion Concentration ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

By systematic tuning of the components of the electrolyte, the performances of dye-sensitized solar cells (DSCs) with an N-heterocyclic carbene iron(II) dye have been significantly improved. The beneficial effects of an increased Li+ ion concentration in the electrolyte lead to photoconversion efficiencies (PCEs) up to 0.66% for fully masked cells (representing 11.8% relative to 100% set for N719) and an external quantum efficiency maximum (EQEmax) up to approximately 25% due to an increased short-circuit current density (JSC). A study of the effects of varying the length of the alkyl chain in 1-alkyl-3-methylimidazolium iodide ionic liquids (ILs) shows that a longer chain results in an increase in JSC with an overall efficiency up to 0.61% (10.9% relative to N719 set at 100%) on going from n-methyl to n-butyl chain, although an n-hexyl chain leads to no further gain in PCE. The results of electrochemical impedance spectroscopy (EIS) support the trends in JSC and open-circuit voltage (VOC) parameters. A change in the counterion from I− to [BF4]− for 1-propyl-3-methylimidazolium iodide ionic liquid leads to DSCs with a remarkably high JSC value for an N-heterocyclic carbene iron(II) dye of 4.90 mA cm−2, but a low VOC of 244 mV. Our investigations have shown that an increased concentration of Li+ in combination with an optimized alkyl chain length in the 1-alkyl-3-methylimidazolium iodide IL in the electrolyte leads to iron(II)-sensitized DSC performances comparable with those of containing some copper(I)-based dyes.

Evaluation of Annealing Effects on TiO2 Nanorod Arrays for Dye-Sensitized Solar Cells by Equivalent Circuit Analysis

2014 ◽  
Vol 609-610 ◽  
pp. 152-158 ◽  
Author(s):  
Mei Rong Sui ◽  
Xiu Quan Gu
Keyword(s):  
Solar Cells ◽  
Equivalent Circuit ◽  
Dye Sensitized Solar Cells ◽  
Equivalent Circuit Model ◽  
Photocurrent Density ◽  
Nanorod Arrays ◽  
Equivalent Circuit Analysis ◽  
Shunt Resistance ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

TiO2 nanorod arrays (NRA) were synthesized via a facile hydrothermal method for preparing the dye-sensitized solar cells (DSSC). It was found that a post-thermal treatment facilitated enhancing the cell efficiency. The cells containing NRs underwent 500 °C annealing exhibited much higher efficiency than those un-sintered ones. Further, the internal resistance analysis was carried out to reveal the mechanism underlying the DSSC performance improvement. Specifically, the equivalent circuit model was employed to derivate the internal resistances, which was consistent with the experimental results. It was found that the sintered cells exhibited a higher series resistance and a lower shunt resistance than the un-sintered ones, suggesting the higher photocurrent density might result from the larger amount of dye loading.

Hybrid Structure of TiO2 Nanofiber and Nanoparticle for Dye-Sensitized Solar Cells

2014 ◽  
Vol 922 ◽  
pp. 356-359
Author(s):  
Ji Sun Kim ◽  
Seong Cheol Shim ◽  
Tae Hwan Hwang ◽  
Won Youl Choi
Keyword(s):  
Solar Cells ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Anatase Phase ◽  
Dye Sensitized Solar Cells ◽  
Hybrid Structure ◽  
Dye Sensitized ◽  
Nanofiber Film ◽  
Sensitized Solar Cells ◽  
Screen Printed

Hybrid structure of TiO2nanofiber and nanoparticle as a photoelectrode was very attractive in dye-sensitized solar cells (DSCs) because TiO2nanoparticle provided a high specific surface area to adsorb the N719 dye and TiO2nanofiber was a direct path to transfer photoelectron from dye to electrode. TiO2nanofiber film was prepared with titanium-tetraisopropoxide (TTIP) and polyvinylpyrrolidone (PVP) based precursor by electro-spinning process. To fabricate the hybrid structure, TiO2nanoparticular paste was screen printed on the TiO2nanofiber film. Electrospun TiO2nanofiber film and screen printed TiO2nanoparticular film were combined in layer by layer method. These films were observed as an anatase phase by X-ray diffraction pattern. Thickness and diameter of TiO2nanofibers were ~5μm and ~400nm, respectively. Thickness and particle size of TiO2particles were ~5μm and ~20nm, respectively. Compared to conventional DSCs, higher short circuit current densities (Jsc) of 6.47 mA/cm2and higher power conversion efficiency of 3.06 % were measured in DSCs having hybrid structure of TiO2nanofiber and nanoparticle. Electrochemical impedance spectroscopy (EIS) was observed to understand an electron transfer and life time.

scholarly journals Study on Carbon Nanocomposite Counterelectrode for Dye-Sensitized Solar Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Yiming Chen ◽  
Haiyan Zhang ◽  
Yuting Chen ◽  
Jiapeng Lin
Keyword(s):  
Solar Cells ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Composite Electrodes ◽  
Dye Sensitized ◽  
Sensitized Solar Cells ◽  
Carbon Nanocomposite ◽  
Nanocomposite Electrodes

Carbon nanocomposite electrodes were prepared by adding carbon nanotubes (CNTs) into carbon black as counterelectrodes of dye-sensitized solar cells(DSSCs). The morphology and structure of carbon nanocomposite electrodes were studied by scanning electron microscopy. The influence of CNTs on the electrochemical performance of carbon nanocomposite electrodes is investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Carbon nano composite electrodes with CNTs exhibit a highly interconnected network structure with high electrical conductivity and good catalytic activity. The influence of different CNTs content in carbon nanocomposite electrodes on the open-circuit voltage, short-circuit current, and filling factor of DSSCs is also investigated. DSSCs with 10% CNTs content exhibit the best photovoltaic performance in our experiments.

Dye-Sensitized Solar Cells Based on Novel Mixed Dyes

2011 ◽  
Vol 383-390 ◽  
pp. 5510-5515
Author(s):  
Tien Tsan Hung
Keyword(s):  
Solar Cells ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Sol Gel ◽  
Dye Sensitized Solar Cells ◽  
Open Circuit ◽  
Membrane Electrode ◽  
Dye Sensitized ◽  
Phthalocyanine Derivative ◽  
Sensitized Solar Cells

Novel phthalocyanine derivative and azo derivative have been synthesized as photosensitizers for the dye-sensitized solar cells (DSSCs). We used sol-gel method to prepare the titanium oxide (TiO2) membrane electrode of the DSSCs. The crystalline phase and surface morphology of TiO2 were characterized by using X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM) to investigate the effects of processing parameters on the films characteristic, microstructure and thickness. The performance of DSSCs was characterized by using electrochemical impedance spectroscopy (EIS) and current-voltage curve analysis. The sensitizing properties of phthalocyanine derivative, azo derivative and mixed dyes were studied, and it was found that the cell consisted of mixed dyes generated the highest power conversion efficiency () of 2.3 %, short circuit photocurrent density (Jsc) of 13.6 mA cm-2, open circuit photovoltage (Voc) of 0.46 V and fill factor (FF) of 0.37 under simulated AM 1.5 irradiation (100 mW cm-2) with a active area of 0.25 cm2.

Composite Polymer Electrolyte for Dye-Sensitized Solar Cells: Role of Multi-Walled Carbon Nanotubes

2010 ◽  
Vol 93-94 ◽  
pp. 31-34 ◽  
Author(s):  
A. Chindaduang ◽  
Pattasuda Duangkaew ◽  
Sirapat Pratontep ◽  
Gamolwan Tumcharern
Keyword(s):  
Solar Cells ◽  
Polymer Electrolyte ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Short Circuit Current ◽  
Composite Polymer Electrolyte ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

We focus on the energy conversion improvement of dye-sensitized solar cells by using poly(ethylene oxide)-multi-walled carbon nanotube (PEO-MWCNT) electrolyte. Compared with the MWCNT-free solar cells, the addition of 0.05 wt.% MWCNTs in the polymer electrolyte results in a dramatic increase of the short-circuit current (Jsc), consequently raising the device performance by approximately 9% under a direct light of the Air Mass 1.5 irradiation at 100 mW cm-2. The role of the conductive carbon materials in the polymer electrolyte have been investigated by means of ionic conductometry, electrochemical impedance spectroscopy and UV-visible spectroscopy. This work demonstrates that MWCNT additives in polymer electrolytes is a convenient yet effective strategy for improving the performance of photovoltaic devices.

scholarly journals Alkali Iodide Deep Eutectic Solvents as Alternative Electrolytes for Dye Sensitized Solar Cells

2021 ◽  
Vol 2 (2) ◽  
pp. 222-236
Author(s):  
Hugo Cruz ◽  
Ana Lucia Pinto ◽  
Noémi Jordão ◽  
Luísa A. Neves ◽  
Luís C. Branco
Keyword(s):  
Solar Cells ◽  
Current Density ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Deep Eutectic Solvents ◽  
Transport Processes ◽  
Experimental Conditions ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

Different alkali deep eutectic solvents (DES), such as LiI:nEG, NaI:nEG, and KI:nEG, have been tested as electrolytes for dye sensitized solar cells (DSSCs). These DSSCs were prepared using pure DES or, alternatively, DES combined with different amounts of iodine (I2). The most important parameters, such as open circuit voltage (VOC), short circuit current density (JSC), fill factor (FF), and the overall conversion efficiency (η), were evaluated. Some DES seem to be promising candidates for DSSC applications, since they present higher VOC (up to 140 mV), similar FF values but less current density values, when compared with a reference electrolyte in the same experimental conditions. Additionally, electrochemical impedance spectroscopy (EIS) has been performed to elucidate the charge transfer and transport processes that occur in DSSCs. The values of different resistance (Ω·cm2) phenomena and recombination/relaxation time (s) for each process have been calculated. The best-performance was obtained for DES-based electrolyte, KI:EG (containing 0.5 mol% I2) showing an efficiency of 2.3%. The efficiency of this DES-based electrolyte is comparable to other literature systems, but the device stability is higher (only after seven months the performance of the device drop to 60%).

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