Improved Performances of Graphite Counter Electrode for Dye-Sensitized Solar Cells by Incorporating Graphene Nanosheets

2012 ◽  
Vol 253-255 ◽  
pp. 689-692 ◽  
Author(s):  
Shun Jian Xu ◽  
Yu Feng Luo ◽  
Wei Zhong ◽  
Xiao Yun Liu ◽  
Zong Hu Xiao ◽  
...  

Graphene nanosheets (GNs) were introduced into graphite counter electrode to construct a graphite/GNs (GGN) counter electrode to enhance the photovoltaic properties of the dye–sensitized solar cells (DSCs). The efficiency of the DSCs with the GGN electrode is 38.4% higher than that of DSCs with graphite electrode. The improved efficiency is attributed to the enhancement in the short circuit photocurrent density and fill factor. The GNs with high conductivity in the GGN electrode are believed to strengthen the contacts among the graphite particles as well as between the carbon film and the substrate, providing enough conductive paths for the transportation of the electrons in the electrode. Therefore, the sheet resistance of the GGN electrode is reduced and the catalytic activity for triiodide ( ) reduction is improved, which are two factors to enhance the efficiency of the cell.

2015 ◽  
Vol 60 (2) ◽  
pp. 1241-1245 ◽  
Author(s):  
Ha-Rim An ◽  
Hyelan An ◽  
Doh-Hyung Riu ◽  
Hyo-Jin Ahn

Abstract We modified the surfaces of F-doped SnO2 thin films using laser patterning to improve the photovoltaic properties of dye-sensitized solar cells. To do so, we varied the laser power density and the distance between laser-patterned lines. First, we investigated three power densities. Higher densities led to higher sheet resistances owing to increases in surface roughnesses. The lowest power density increased surface roughness without electrical degradation. Next, we explored three line spacings at a fixed power density. The films with the narrowest spacing exhibited the highest power conversion efficiency (~7.00%), the highest short-circuit photocurrent density (16.28 mA/cm2), and a good fill factor (58.82%).


2018 ◽  
Vol 382 ◽  
pp. 369-373
Author(s):  
Usana Mahanitipong ◽  
Preeyapat Prompan ◽  
Rukkiat Jitchati

The four thiocyanate free ruthenium(II) complexes; [Ru(N^N)2(C^N)]PF6were synthesized and characterized for dye sensitized solar cells (DSSCs). The results showed that the broad absorptions covered the visible region from metal to ligand charge transfer (MLCT) were obtained with the main peaks at 560, 490 and 400 nm. The materials were studied DSSC performance under standard AM 1.5. Compound PP1 showed the power conversion efficiency (PCE) at 3.10%, with a short-circuit photocurrent density (Jsc) of 7.99 mA cm-2, an open-circuit photovoltage (Voc) of 563 mV and a high fill factor (ff) of 0.690.


Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2922 ◽  
Author(s):  
Zainal Arifin ◽  
Suyitno Suyitno ◽  
Syamsul Hadi ◽  
Bayu Sutanto

In this study, dye-sensitized solar cells (DSSCs) were fabricated using double-layer photoanodes consisting of TiO2 nanoparticles (NPs) and Zn-doped TiO2 hollow fibers (HFs). The TiO2 HFs were prepared by co-axial electrospinning and used as the light-scattering layer in the DSSC. The thickness variations of the TiO2 NP and Zn-doped TiO2 HF photoanode layers affect the performance of the DSSC, especially the short-circuit photocurrent density. The thickness of the TiO2 NP layer significantly affected the absorbance of photons and N719 dye molecules in the double-layer photoanode, while that of the Zn-doped TiO2 HF layer affected the scattering of light, as indicated by the low light transmittance in the photoanode. Conventional DSSCs consist of single-layer photoanodes, and exhibit relatively low efficiency, i.e., 1.293% and 0.89% for TiO2 NP and Zn-doped TiO2 HF, respectively. However, herein, the highest efficiency of the DSSC (3.122%) was achieved with a 15 μm NP-5 μm HF photoanode, for which the short-circuit photocurrent density, open-circuit photovoltage, and fill factor were 15.81 mA/cm2, 0.566 V, and 34.91%, respectively.


2021 ◽  
Vol 1016 ◽  
pp. 863-868
Author(s):  
Tika Erna Putri ◽  
Yuan Hao ◽  
Fadzai Lesley Chawarambwa ◽  
Hyunwoong Seo ◽  
Min Kyu Son ◽  
...  

The losses of solar cells are consisted of electrical losses and optical losses. Optical losses chiefly reduce the short-circuit current. Here we apply bifacial cell approach to increase light absorption and the short-circuit current of dye sensitized solar cells (DSSCs). We have employed activated carbon (AC) as a very low cost counter electrode, an alternative to Pt counter electrode. Addition of dimethyl sulfoxide (DMSO) and titanium carbonitride (TiCN) to AC increase the efficiency of bifacial DSSC at a mirror angle of from 5.10% to and , respectively. These results indicate that AC has the potential to replace Pt as a very low cost counter electrode of bifacial DSSCs. The bifacial DSSC system using double plane mirrors improve PCE to for Pt counter electrode at a mirror angle of , and for AC counter electrode at a mirror angle of , respectively.


RSC Advances ◽  
2014 ◽  
Vol 4 (68) ◽  
pp. 36226-36233 ◽  
Author(s):  
K. Saranya ◽  
N. Sivasankar ◽  
A. Subramania

Graphene nanosheets (GNs) are prepared from natural graphite by a simple ecofriendly microwave-assisted exfoliation technique.


2013 ◽  
Vol 750-752 ◽  
pp. 873-876
Author(s):  
Zong Hu Xiao ◽  
Wei Zhong ◽  
Shun Jian Xu ◽  
Yong Ping Luo

Zinc oxide (ZnO) with various morphologies consisting of nanoparticles with a diameter of approximately 20 nm have been successfully prepared by hydrothermal method from zinc nitrate (Zn (NO3)2)/carbamide (CO(NH2)2) solution. The morphologies and phase structures of the as-prepared ZnO samples were characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD). Results show that the morphologies of the as-prepared ZnO are successively present in broom-like, cabbage-like, chinese cabbage-like, honeycomb-like with the increase of the CO(NH2)2concentration from 0.1 M to 1 M. The photovoltaic performances of dye-sensitized solar cells, based on ZnO with various morphologies as the photoelectrodes, are unobvious. With the morphologies of ZnO evolving, the short circuit photocurrent density (Jsc) increases from 2.35 to 3.72 mA/cm2, the fill factor (FF) increases from 0.400 to 0.570, and the corresponding conversion efficiency (η) varies from 0.520 % to 1.200 %. The lowηmay be due to the formation of the Zn2+/dye polymers.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mengmei Pan ◽  
Hanjun Liu ◽  
Zhongyu Yao ◽  
Xiaoli Zhong

Trace amount Ca-doped TiO2films were synthesized by the hydrothermal method and applied as photoanodes of dye-sensitized solar cells (DSSCs). To prepare Ca-doped TiO2film electrodes, several milliliters of Ca(NO3)2solution was added in TiO2solution during the hydrolysis process. The improvements of DSSCs were confirmed by photocurrent density-voltage (J-V) characteristics, electrochemical impedance spectroscopy (EIS) measurements. Owing to the doping effect of Ca, the Ca-doped TiO2thin film shows power conversion efficiency of 7.45% for 50 ppm Ca-doped TiO2electrode, which is higher than that of the undoped TiO2film (6.78%) and the short-circuit photocurrent density(Jsc)increases from 13.68 to 15.42 mA·cm−2. The energy conversion efficiency and short-circuit current density(Jsc)of DSSCs were increased due to the faster electron transport in the Ca-doped TiO2film. When Ca was incorporated into TiO2films, the electrons transport faster and the charge collection efficiencyηccis higher than that in the undoped TiO2films.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Joe Otsuki ◽  
Yusho Takaguchi ◽  
Daichi Takahashi ◽  
Palanisamy Kalimuthu ◽  
Surya Prakash Singh ◽  
...  

We have prepared a novel piperidine-donor-substituted perylene sensitizer, PK0002, and studied the photovoltaic performance in dye-sensitized solar cells (DSSCs). Physical properties and photovoltaic performance of this new perylene derivative PK0002 are reported and compared with those of unsubstituted perylene sensitizer, PK0003. PK0002, when anchored to nanocrystalline TiO2 films, achieves very efficient sensitization across the whole visible range extending up to 800 nm. The incident photon-to-current conversion efficiency (IPCE) spectrum was consistent with the absorption spectrum and resulted in a high short-circuit photocurrent density (Jsc) of 8.8 mA cm-2. PK0002 showed higher IPCE values than PK0003 in the 520–800 nm region. Under standard AM 1.5 irradiation (100 mW cm-2) and using an electrolyte consisting of 0.6 M dimethylpropyl-imidazolium iodide, 0.05 M I2, 0.1 M LiI, and 0.5 M tert-butylpyridine in acetonitrile, a solar cell containing sensitizer PK0002 yielded a short-circuit photocurrent density of 7.7 mA cm-2, an open-circuit photovoltage of 0.57 V, and a fill factor of 0.70, corresponding to an overall conversion efficiency of 3.1%.


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