scholarly journals Effect of π-Conjugated Spacer in N-Alkylphenoxazine-Based Sensitizers Containing Double Anchors for Dye-Sensitized Solar Cells

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1304
Author(s):  
Yung-Sheng Yen ◽  
Velu Indumathi

A series of novel double-anchoring dyes for phenoxazine-based organic dyes with two 2-cyanoacetic acid acceptors/anchors, and the inclusion of a 2-ethylhexyl chain at the nitrogen atom of the phenoxazine that is connected with furan, thiophene, and 3-hexylthiophene as a linker, are used as sensitizers for dye-sensitized solar cells. The double-anchoring dye exhibits strong electronic coupling with TiO2, provided that there is an efficient charge injection rate. The result showed that the power conversion efficiency of DP-2 with thiophene linker-based cell reached 3.80% higher than that of DP-1 with furan linker (η = 1.53%) under standard illumination. The photovoltaic properties are further tuned by co-adsorption strategy, which improved power conversion efficiencies slightly. Further molecular theoretical computation and electrochemical impedance spectroscopy analysis of the dyes provide further insight into the molecular geometry and the impact of the different π-conjugated spacers on the photophysical and photovoltaic performance.

2010 ◽  
Vol 1270 ◽  
Author(s):  
Braden Bills ◽  
Mariyappan Shanmugam ◽  
Mahdi Farrokh Baroughi ◽  
David Galipeau

AbstractThe performance of dye-sensitized solar cells (DSSCs) is limited by the back-reaction of photogenerated electrons from the porous titanium oxide (TiO2) nanoparticles back into the electrolyte solution, which occurs almost exclusively through the interface. This and the fact that DSSCs have a very large interfacial area makes their performance greatly dependant on the density and activity of TiO2 surface states. Thus, effectively engineering the TiO2/dye/electrolyte interface to reduce carrier losses is critically important for improving the photovoltaic performance of the solar cell. Atomic layer deposition (ALD), which uses high purity gas precursors that can rapidly diffuse through the porous network, was used to grow a conformal and controllable aluminum oxide (Al2O3) and hafnium oxide (HfO2) ultra thin layer on the TiO2 surface. The effects of this interfacial treatment on the DSSC performance was studied with dark and illuminated current-voltage and electrochemical impedance spectroscopy (EIS) measurements.


Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1645 ◽  
Author(s):  
Seong Il Cho ◽  
Hye Kyeong Sung ◽  
Sang-Ju Lee ◽  
Wook Hyun Kim ◽  
Dae-Hwan Kim ◽  
...  

At an elevated temperature of 90 °C, a chemical bath deposition using an aqueous solution of Zn(NO3)2·6H2O and (CH2)6N4 resulted in the formation of both nanoflowers and microrods of ZnO on F-doped SnO2 glass with a seed layer. The nanoflowers and microrods were sensitized with dyes for application to the photoelectrodes of dye-sensitized solar cells (DSSCs). By extending the growth time of ZnO, the formation of nanoflowers was reduced and the formation of microrods favored. As the growth time was increased from 4 to 6 and then to 8 h, the open circuit voltage (Voc) values of the DSSCs were increased, whilst the short circuit current (Jsc) values varied only slightly. Changes in the dye-loading amount, dark current, and electrochemical impedance were monitored and they revealed that the increase in Voc was found to be due to a retardation of the charge recombination between photoinjected electrons and I3− ions and resulted from a reduction in the surface area of ZnO microrods. A reduced surface area decreased the dye contents adsorbed on the ZnO microrods, and thereby decreased the light harvesting efficiency (LHE). An increase in the electron collection efficiency attributed to the suppressed charge recombination counteracted the decreased LHE, resulting in comparable Jsc values regardless of the growth time.


2021 ◽  
Author(s):  
S. Revathi ◽  
A Pricilla Jeyakumari

Abstract Currently, the TiO2/CdS photoanodes based dye sensitized solar cells (DSSCs) have shown extraordinary developments in the photo conversion efficiency. In this report, pristine TiO2, CdS and various molar ratios of TiO2/CdS photoanodes were prepared by one step microwave irradiation route and followed by doctor blade method. The sheet like morphology of the TiO2 and CdS nanoparticles were clearly evident from the SEM and TEM images. A significant reduction band gap with enhanced light absorption and rapid prevention of electron hole pair was explored by UV-DRS and PL studies. The photocurrent density-voltage (J-V) and electrochemical impedance (EIS) characteristics were analyzed for assembled solar cell. The photo-conversion efficiency of 12.8% was obtained with the configuration TiO2/CdS (200 mg) that represent a 2.5 fold increment compared to bare TiO2 (5.33%) as well as commercial Pt (6.11%). The experimental results are discussed.


2021 ◽  
Vol 2101 (1) ◽  
pp. 012066
Author(s):  
Hao Yang ◽  
Hao Fan ◽  
Junhong Duan

Abstract In this work, Mg-doped SnO2 materials with different molar ratios were synthesized by hydrothermal method. Based on the UV-Vis study, band gap (Eg) of the Mg-doped SnO2 is adjusted from 3.76 eV to 3.65 eV via 3 at% concentrations. Results of photovoltaic measurement for dye-sensitized solar cells (DSCs) based on Mg-doped SnO2 film as photoanode indicate that the doping of Mg ions can improve the open-circuit voltage (V oc) of the DSCs, while the electric current density (J sc) of the DSCs is almost unchanged. The cells were measured at 3 days intervals within 24 days after fabrication. Power conversion efficiency (PCE) of 3 at% Mg-doped SnO2 DSCs increases step by step and achieves 4.38% as the cell is tested after 18 days. Electrochemical impedance spectroscopy (EIS) analysis shows that Mg doping enhances light collection, increased the number of photogenerated electrons and inhibits charge recombination.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Yiming Chen ◽  
Haiyan Zhang ◽  
Yuting Chen ◽  
Jiapeng Lin

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.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Sule Erten-Ela

Triphenylene diamine sensitizer comprising donor, electron conducting, and anchoring group is synthesized for a potential application in dye-sensitized solar cells. Absorption spectrum, electrochemical and photovoltaic properties of triphenylene diamine have been investigated. Two different electrodes are used for dye-sensitized solar cells. The performances of ZnO nanorod electrodes are compared to ZnO : CdO nanocomposite electrode. Also, the theoretical calculations for HOMO and LUMO orbitals are used to estimate the photovoltaic properties of organic sensitizer in the design stage. ZnO : CdO nanocomposite electrode-based dye-sensitized solar cell sensitized with organic sensitizer exhibits higher efficiencies than ZnO nanorod electrode. For a typical device, a solar energy conversion efficiency (η) of 0.80 based on ZnO : CdO nanocomposite is achieved under simulated AM 1.5 solar irradiation (100 mW cm−2) with a short circuit photocurrent density (Jsc) of 3.10 mA/cm2, an open-circuit voltage (Voc) of 480 mV, and a fill factor (FF) of 0.57. These results suggest that the ZnO : CdO nanocomposite system is a good selection and a promising candidate for electrode system in dye-sensitized solar cells.


2014 ◽  
Vol 705 ◽  
pp. 320-323 ◽  
Author(s):  
Jung Eun Nam ◽  
Hyo Jeong Jo ◽  
Dae Ho Son ◽  
Dae Hwan Kim ◽  
Jin Kyu Kang

Anti-reflective (AR) layers play an important role in boosting the amount of light entering a device and reducing reflection losses in a device, thereby enhancing the power conversion efficiency of solar cells. We have coated an AR layer on the surface of a dye-sensitized solar cell device by using an electron beam evaporation system and investigated the effects of the AR layer by measuring photovoltaic performance. The AR layer is found to increases the Jsc and η of the solar cell.


Sign in / Sign up

Export Citation Format

Share Document