Graded Multilayered TiO2 Photoelectrode for Improving the Performance of Dye Solar Cells

2013 ◽  
Vol 756 ◽  
pp. 190-196 ◽  
Author(s):  
Adel Eskandar Samsudin ◽  
Muti Mohamed Norani
Keyword(s):  
Conversion Efficiency ◽  
Electrochemical Impedance ◽  
Bottom Layer ◽  
Multilayered Structure ◽  
Glass Electrode ◽  
Tio2 Electrode ◽  
Solar Simulator ◽  
Dye Solar Cells ◽  
Composite Configuration ◽  
The One

Numerous research have been conducted to improve the efficiency of dye solar cell (DSC) through the study on its components namely the dye, electrolyte, counter electrode and the photoelectrode material. This paper presents the study on the usage of a multilayered structure with different composition of TiO2 nanoparticles/aggregates composites starting with the top layer consisting of purely aggregates and ending with the bottom layer consisting of wholly nanoparticles as the photoelectrode material. The graded composition profile of increasing amount of aggregates at the top of the photoelectrode and increasing amount of nanoparticles at the bottom of the photoelectrode will allow for the enhancement in the optical properties and kinetics of DSC. The layers were screen-printed onto FTO coated glass substrate to form the photoelectrodewith an active area of 1 cm2 and thickness of 12 µm. The N719 dye-coated TiO2 electrode was then assembled into sandwich configuration with platinized conducting glass electrode and injected with iodide/tri-iodide redox couples electrolyte.Kinetics and the underlying transport properties of the assembled DSCs were measured by Electrochemical Impedance Spectroscopy (EIS). The response of the cells towards a spectrum of light frequencies was measured using Incident Photon to Electron Conversion Efficiency (IPCE). Conversion efficiency was measured using a 100 mW/cm2 solar simulator. Highest efficiency was found for the multilayered photoelectrode configuration at 4.58% with 14% improvement over the DSC with pure aggregate.DSCs with the multilayered composite configuration have higher current density, Jscwith an increase of 2.249 mA cm-1 compared to the one with only nanoparticles and only aggregates layer. Multilayer configuration has shown significant improvement in the quantum efficiency by exhibiting higher light absorption especially in the range of 500-550 nm light wavelength by about 12.9%.The increase in the conversion efficiency of DSCs with multilayer configuration is also attributed to the improvement in the electron diffusion as evident by the EIS measurement.

Optimized TiO2 Nanocrystallites Aggregates for Enhanced Efficiency in Dye Solar Cells

2014 ◽  
Vol 917 ◽  
pp. 35-44 ◽  
Author(s):  
Siti Nur Azella Zaine ◽  
Norani Muti Mohamed ◽  
Mohamad Azmi Bustam
Keyword(s):  
Solar Cells ◽  
Light Scattering ◽  
Water Content ◽  
Calcination Temperature ◽  
Conversion Efficiency ◽  
Internal Surface Area ◽  
Solar Simulator ◽  
Vis Spectroscopy ◽  
Dye Solar Cells ◽  
28 Nm

TiO2 aggregates-based dye solar cells (DSCs) have gained an increasing attention due to their enhanced harvesting of light radiance. The capability of this photoelectrode material is attributed to the submicron spherical aggregates that introduce light scattering effect which can generate more electrons whilst high internal surface area for dye chemisorption is provided by nanocrystallites which made up the aggregates. Here, TiO2 aggregates (0.45-0.20 μm) composing of nanocrystallites (10-28 nm) with desired physicochemical properties for enhanced overall light conversion efficiency of DSC were synthesized by varying the water content in the hydrolysis of titanium alkoxide in ethanol and calcination temperature. TiO2 aggregates obtained were characterized using FESEM, XRD and UV-Vis spectroscopy. The assembled DSCs were then evaluated using solar simulator under AM 1.5 (100 mW/cm2) simulated sunlight. With higher water content in the hydrolysis process, the aggregates reduce in size and lose their spherical shapes resulting in lower absorption intensity indicating the occurrence of low light scattering in the TiO2 film. Nanocrystallites were found to have an increasing size of 12 nm to 28 nm with increasing calcination temperature of 400°C to 700°C. Sample of aggregates calcined at 450°C recorded the highest efficiency (~4%). Highest conversion efficiency was observed for DSC that used well-defined spherical TiO2 aggregates composing of nanocrystallites which were synthesized at optimum synthesis parameter which is by using ethanol with low water content (0.9 vol%) followed by calcination at 450°C. Thus, optimized TiO2 nanocrystallites which form spherical aggregate is critical in order to improve light harvesting efficiency of DSCs.

The Effect of Calcinations Temperature on the Performance of TiO2 Aggregates-Based Dye Solar Cells (DSCs)

2011 ◽  
Vol 364 ◽  
pp. 248-253 ◽  
Author(s):  
Nur Azella Zaine Siti ◽  
Muti Mohamed Norani ◽  
Mohamad Azmi Bustam
Keyword(s):  
Conversion Efficiency ◽  
Chemical Properties ◽  
Energy Conversion Efficiency ◽  
Synthesis Process ◽  
Solar Simulator ◽  
Electron Generation ◽  
Physico Chemical ◽  
Vis Spectroscopy ◽  
Dye Solar Cells ◽  
Hydrolysis Of

Development of novel TiO2 nanostructures as the photo-electrode material is one possible solution to control the competition between electron generation and recombination which is the main constraint of obtaining higher conversion efficiency of dye solar cell (DSC). By manipulating the synthesis process, desired TiO2 nanostructure with specific properties can be obtained to enhance solar energy conversion efficiency. In this study, the effect of calcinations temperature towards physico-chemical properties of synthesized TiO2 aggregates and their influence on overall light conversion efficiency of DSC has been investigated. TiO2 aggregates (0.45 µm) composing of nanocrystallites (10-40 nm), were synthesized through hydrolysis of dilute titanium alkoxide in ethanol. The synthesized samples have been characterized using FESEM, XRD and UV-Vis spectroscopy. DSCs were then assembled and evaluated using solar simulator under 100 mW/cm2 illuminations. The size of nanocrystallites was found to increase with increasing calcinations temperature where the 500°C produced the 21 nm sized nanocrystallites, the optimum size for highest absorption of the dye resulting in the highest efficiency. TiO2 aggregates-based DSC demonstrated better performance compared to nanoparticles (P-25)-based DSC. This is attributed to the enhanced scattering introduced by micron-sized aggregates.

scholarly journals Antireflection Improvement and Junction Quality Optimization of Si/PEDOT:PSS Solar Cell with the Introduction of Dopamine@Graphene

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5986
Author(s):  
Tao Chen ◽  
Hao Guo ◽  
Leiming Yu ◽  
Tao Sun ◽  
Anran Chen ◽  
...  
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
High Performance ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrochemical Impedance Spectra ◽  
Solar Cell Performance ◽  
Photovoltaic Conversion ◽  
Photovoltaic Conversion Efficiency

Si/PEDOT: PSS solar cell is an optional photovoltaic device owing to its promising high photovoltaic conversion efficiency (PCE) and economic manufacture process. In this work, dopamine@graphene was firstly introduced between the silicon substrate and PEDOT:PSS film for Si/PEDOT: PSS solar cell. The dopamine@graphene was proved to be effective in improving the PCE, and the influence of mechanical properties of dopamine@graphene on solar cell performance was revealed. When dopamine@graphene was incorporated into the cell preparation, the antireflection ability of the cell was enhanced within the wavelength range of 300~450 and 650~1100 nm. The enhanced antireflection ability would benefit amount of the photon-generated carriers. The electrochemical impedance spectra test revealed that the introduction of dopamine@graphene could facilitate the separation of carriers and improve the junction quality. Thus, the short-circuit current density and fill factor were both promoted, which led to the improved PCE. Meanwhile, the influence of graphene concentration on device performances was also investigated. The photovoltaic conversion efficiency would be promoted from 11.06% to 13.15% when dopamine@graphene solution with concentration 1.5 mg/mL was applied. The achievements of this study showed that the dopamine@graphene composites could be an useful materials for high-performance Si/PEDOT:PSS solar cells.

scholarly journals SiO2Antireflection Coatings Fabricated by Electron-Beam Evaporation for Black Monocrystalline Silicon Solar Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Minghua Li ◽  
Hui Shen ◽  
Lin Zhuang ◽  
Daming Chen ◽  
Xinghua Liang
Keyword(s):  
Electron Beam ◽  
Solar Cells ◽  
Conversion Efficiency ◽  
Single Layer ◽  
Bottom Layer ◽  
Energy Conversion Efficiency ◽  
Electron Beam Evaporation ◽  
Silicon Solar Cells ◽  
Antireflection Coatings ◽  
Efficiency Increase

In this work we prepared double-layer antireflection coatings (DARC) by using the SiO2/SiNx:H heterostructure design. SiO2thin films were deposited by electron-beam evaporation on the conventional solar cell with SiNx:H single-layer antireflection coatings (SARC), while to avoid the coverage of SiO2on the front side busbars, a steel mask was utilized as the shelter. The thickness of the SiNx:H as bottom layer was fixed at 80 nm, and the varied thicknesses of the SiO2as top layer were 105 nm and 122 nm. The results show that the SiO2/SiNx:H DARC have a much lower reflectance and higher external quantum efficiency (EQE) in short wavelengths compared with the SiNx:H SARC. A higher energy conversion efficiency of 17.80% was obtained for solar cells with SiO2(105 nm)/SiNx:H (80 nm) DARC, an absolute conversion efficiency increase of 0.32% compared with the conventional single SiNx:H-coated cells.

scholarly journals Laser contrast and other key parameters enhancing the laser conversion efficiency in ion acceleration regime

2018 ◽  
Vol 167 ◽  
pp. 02002 ◽  
Author(s):  
Lorenzo Torrisi
Keyword(s):  
Electric Field ◽  
Conversion Efficiency ◽  
Laser Light ◽  
Laser Intensity ◽  
Multilayered Structure ◽  
Maximum Energy ◽  
Ion Acceleration ◽  
Surface Geometry ◽  
Laser Parameters ◽  
Target Composition

Measurements of ion acceleration in plasma produced by fs lasers at intensity of the order of 1018 W/cm2 have been performed in different European laboratories. The forward emission in target-normal-sheath-acceleration (TNSA) regime indicated that the maximum energy is a function of the laser parameters, of the irradiation conditions and of the target properties.In particular the laser intensity and contrast play an important role to maximize the ion acceleration enhancing the conversion efficiency. Also the use of suitable prepulses, focal distances and polarized laser light has important roles. Finally the target composition, surface, geometry and multilayered structure, permit to enhance the electric field driving the forward ion acceleration.Experimental measurements will be reported and discussed.

Performance of TiO2 Aggregates-Based Dye Solar Cells

2013 ◽  
Vol 737 ◽  
pp. 137-144 ◽  
Author(s):  
Norani Muti Mohamed ◽  
Siti Nur Azella Zaine
Keyword(s):  
Solar Cells ◽  
Light Scattering ◽  
Water Content ◽  
Calcination Temperature ◽  
Conversion Efficiency ◽  
Light Harvesting ◽  
Dye Solar Cells ◽  
Harvesting Efficiency ◽  
Light Harvesting Efficiency ◽  
20 Nm

TiO2 aggregates-based dye solar cells (DSCs) have gained an increasing interest due to their better light harvesting efficiency as a result of enhanced light scattering effect from the submicron spherical aggregates that can generate more electrons and the high internal surface area for dye chemisorption provided by nanocrystallites which made up the aggregates. Optimized TiO2 aggregates (0.45 µm) composing of nanocrystallites (10-40 nm) with desired physicochemical properties for enhanced overall light conversion efficiency of DSC were synthesized by varying the calcination temperature and water content in the hydrolysis of titanium alkoxide in ethanol. TiO2 aggregates obtained were characterized using FESEM, XRD and UV-Vis spectroscopy. The assembled DSCs were then evaluated using solar simulator under AM 1.5 (100 mW/cm2) simulated sunlight. Nanocrystallites were found to have an increasing size of 12 nm to 36 nm with increasing calcination temperature of 400C to 600C. Sample of aggregates calcined at 500C recorded the highest efficiency (4.456%) as the 20-nm nanocrystallites produced is considered to be the optimum size for dye absorption. With higher water content in the hydrolysis process, the aggregates lose their spherical shapes resulting in lower absorption intensity indicating the occurrence of low light scattering in the TiO2 film. Highest conversion efficiency was observed for DSC that used well-defined spherical TiO2 aggregates composing of 20-nm nanocrystallites which were synthesized using ethanol with low water content (0.9 vol%) followed by calcination at 500C. Thus, optimized TiO2 nanocrystallites which form spherical aggregate is critical in order to improve light harvesting efficiency of DSCs.

scholarly journals Investigation of Temperature and Aging Effects in Nanostructured Dye Solar Cells Studied by Electrochemical Impedance Spectroscopy

2009 ◽  
Vol 2009 ◽  
pp. 1-15 ◽  
Author(s):  
Minna Toivola ◽  
Janne Halme ◽  
Lauri Peltokorpi ◽  
Peter Lund
Keyword(s):  
Solar Cells ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Aging Effects ◽  
Transfer Resistance ◽  
Deterioration Rate ◽  
Dye Solar Cells ◽  
Effects Of Aging

Effects of aging and cyclically varying temperature on the electrical parameters of dye solar cells were analyzed with electrochemical impedance spectroscopy. Photoelectrode total resistance increased as a function of time due to increasing electron transport resistance in theTiO2film. On the other hand, photoelectrode recombination resistance was generally larger, electron lifetimes in theTiO2were film longer, and charge transfer resistance on the counter electrode was smaller after the temperature treatments than before them. These effects correlated with the slower deterioration rate of the temperature-treated cells, in comparison to the reference cells.

Effect of Ge Thin Layer Position on Formation and Property of CZTSSe Thin Films and Solar Cells Prepared by Sputtering Method

2017 ◽  
Vol 895 ◽  
pp. 23-27
Author(s):  
Jin Ze Li ◽  
Hong Lie Shen ◽  
Yu Fang Li ◽  
Wei Wang
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Solar Cell ◽  
Thin Layer ◽  
Conversion Efficiency ◽  
Bottom Layer ◽  
Window Layer ◽  
Structural Morphology ◽  
Ge Doping ◽  
Layer Position

In this work we deposited a Ge thin layer under or upon Cu-Zn-Sn-S precursor by sputtering, followed by selenization process to obtain Ge doped CZTSSe thin films. A comparison of structural, morphology and optoelectrical property on Ge doped CZTSSe thin films with different Ge layer position was studied. It was found that even a little amount of Ge doping could affect the crystallization of CZTSSe grains. The solar cells based on two kinds of precursors both had VOC improvement compared with undoped CZTSSe solar cell. However, due to the inner stress in CZTSSe thin film, cracks appeared between the interface of buffer layer and window layer in CZTSSe solar cell with Ge bottom layer, leading to the decrease of conversion efficiency. With the help of Ge in reducing bulk recombination, CZTSSe solar cell based on Cu-Zn-Sn-S precursor with Ge top layer had a conversion efficiency of 5.38%, in contrast to 3.01% and 4.30% of CZTSSe solar cell with Ge bottom layer and undoped CZTSSe solar cell, respectively.

Titanium Dioxide Nanotubes Decorated with Nanoparticles for Dye Sensitized Solar Cells

2011 ◽  
Vol 1303 ◽  
Author(s):  
Xuan Pan ◽  
Yong Zhao ◽  
Changhong Chen ◽  
Zhaoyang Fan
Keyword(s):  
Titanium Dioxide ◽  
Solar Cells ◽  
Conversion Efficiency ◽  
Electrochemical Impedance ◽  
Dye Sensitized Solar Cells ◽  
Photon Absorption ◽  
Device Performance ◽  
Dye Sensitized ◽  
Dye Loading ◽  
Sensitized Solar Cells

ABSTRACTThe titanium dioxide (TiO2) nanoparticle (NP) structure has higher surface area and dye loading value to increase photon absorption while the nanotube (NT) can suppress the random walk phenomena to enhance carrier collection. In this work, hydrothermal method was utilized to infiltrate the TiO2 nanotube array by TiO2 nanoparticles with the aim of combining the advantages of both nanostructures to improve dye sensitized solar cells (DSSCs) efficiency. Structure morphology, device performance, and electrochemical properties were investigated. SEM observation confirmed that around 10 nm TiO2 nanoparticles uniformly covered the NT wall. TiO2 NT samples at three different lengths: 8 μm, 13 μm and 20 μm, decorated with different amount of nanoparticles were studied to optimize the structure for light absorption and electron transport to achieve high solar conversion efficiency. Electrochemical impedance spectroscopy (EIS) was also employed to investigate the cells’ parameters: electron lifetime (τ), diffusion length (Ln) et al, to gain insight on the device performance. The incident photon conversion efficiency (IPCE) was also reported.

scholarly journals Preparation of Vertically Aligned ZnO/TiO2Core-Shell Composites for Dye-Sensitized Solar Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Lung-Chuan Chen ◽  
Shuei-Feng Tsai ◽  
Jean-Hong Chen ◽  
Gaun-Wen Wang
Keyword(s):  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Indium Tin Oxide ◽  
Electrochemical Impedance ◽  
Power Conversion ◽  
Dye Sensitized Solar Cells ◽  
Dye Adsorption ◽  
Electron Recombination ◽  
Photocurrent Spectroscopy ◽  
Vertically Aligned

Vertically aligned ZnO/TiO2(VA-ZnO/TiO2) core-shell composites deposited on ZnO-seeded indium tin oxide (ITO) glasses have been synthesized by a chemical bath deposition approach for growing one-dimensional ZnO structure followed by a spin procedure for coating TiO2on the surface of ZnO structure. The influences of the cycles of spin coating of TiO2(CSCT) on the properties of VA-ZnO/TiO2and performances of the assembled DSSCs were studied. The power conversion efficiency of the VA-ZnO/TiO2-based DSSC measured under illumination of 100 mW/cm2and AM 1.5 can reach 0.81%, representing 93% improvement when compared with that of the pristine VA-ZnO electrode (0.42%). The intensity-modulated photocurrent spectroscopy (IMPS) and electrochemical impedance spectroscopy (EIS) were applied to study the kinetics and interfacial transfer of the photogenerated electrons. Both the photocurrent and power conversion efficiency correlate well with the steady state electron density. Enlargement in surface area and dye adsorption, suppression of dissolution of Zn2+, diminishment in electron recombination, and fast transfer of injected electrons from excited dyes to TiO2conduction bands arising from coating TiO2on VA-ZnO are regarded as the predominant causes for this improvement.

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