Efficiency of Electron Injection in Dye-Sensitized Semiconductor Films

2010 ◽  
Vol 451 ◽  
pp. 79-95 ◽  
Author(s):  
Ryuzi Katoh ◽  
Akihiro Furube
Keyword(s):  
High Performance ◽  
Transient Absorption ◽  
Electron Injection ◽  
Transient Absorption Spectroscopy ◽  
Excitation Wavelength ◽  
Semiconductor Films ◽  
Nanocrystalline Films ◽  
Experimental Conditions ◽  
Nanocrystalline Tio2 ◽  
Dye Sensitized

The efficiency of electron injection (inj) in dye-sensitized nanocrystalline films has been studied by means of transient absorption spectroscopy. We observed inj of nearly unity for N3 dye adsorbed on nanocrystalline TiO2 films (N3/TiO2). We examined the effects of various experimental conditions, such as light intensity, excitation wavelength, and presence of additives (4-tert- butylpyridine, tBP and Li ions), on inj. We also used various semiconductors and sensitizer dyes to study the effect of free energy change (G) on inj. These results give us new insights for developing high-performance solar cell devices.

Effect of excitation wavelength on electron injection efficiency in dye-sensitized nanocrystalline TiO2 and ZrO2 films

2006 ◽  
Vol 9 (5-6) ◽  
pp. 639-644 ◽  
Author(s):  
Ryuzi Katoh ◽  
Akihiro Furube ◽  
Miki Murai ◽  
Yoshiaki Tamaki ◽  
Kohjiro Hara ◽  
...  
Keyword(s):  
Electron Injection ◽  
Excitation Wavelength ◽  
Nanocrystalline Tio2 ◽  
Injection Efficiency ◽  
Dye Sensitized ◽  
Electron Injection Efficiency

scholarly journals Comparison of electron injection and recombination on TiO 2 nanoparticles and ZnO nanorods photosensitized by phthalocyanine

2018 ◽  
Vol 5 (7) ◽  
pp. 180323 ◽  
Author(s):  
K. Virkki ◽  
E. Tervola ◽  
M. Ince ◽  
T. Torres ◽  
N. V. Tkachenko
Keyword(s):  
Zinc Oxide ◽  
Solar Cell ◽  
Transient Absorption ◽  
Zno Nanorods ◽  
Electron Injection ◽  
Primary Electron ◽  
Transient Absorption Spectroscopy ◽  
Dye Sensitized Solar Cell ◽  
Dye Sensitized ◽  
Similar Band

Titanium dioxide (TiO 2 ) and zinc oxide (ZnO) semiconductors have similar band gap positions but TiO 2 performs better as an anode material in dye-sensitized solar cell applications. We compared two electrodes made of TiO 2 nanoparticles and ZnO nanorods sensitized by an aggregation-protected phthalocyanine derivative using ultrafast transient absorption spectroscopy. In agreement with previous studies, the primary electron injection is two times faster on TiO 2 , but contrary to the previous results the charge recombination is slower on ZnO. The latter could be due to morphology differences and the ability of the injected electrons to travel much further from the sensitizer cation in ZnO nanorods.

scholarly journals Comparing Donor- and Acceptor-Originated Exciton Dynamics in Non-Fullerene Acceptor Blend Polymeric Systems

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1770
Author(s):  
Chan Im ◽  
Sang-Woong Kang ◽  
Jeong-Yoon Choi ◽  
Jongdeok An
Keyword(s):  
Flexible Electronics ◽  
Transient Absorption ◽  
Film Formation ◽  
Transient Absorption Spectroscopy ◽  
Excitation Wavelength ◽  
Polymeric Systems ◽  
Donor And Acceptor ◽  
Novel Material ◽  
Spectrally Resolved ◽  
Energy Strategies

Non-fullerene type acceptors (NFA) have gained attention owing to their spectral extension that enables efficient solar energy capturing. For instance, the solely NFA-mediated absorbing region contributes to the photovoltaic power conversion efficiency (PCE) as high as ~30%, in the case of the solar cells comprised of fluorinated materials, PBDB-T-2F and ITIC-4F. This implies that NFAs must be able to serve as electron donors, even though they are conventionally assigned as electron acceptors. Therefore, the pathways of NFA-originated excitons need to be explored by the spectrally resolved photovoltaic characters. Additionally, excitation wavelength dependent transient absorption spectroscopy (TAS) was performed to trace the nature of the NFA-originated excitons and polymeric donor-originated excitons separately. Unique origin-dependent decay behaviors of the blend system were found by successive comparing of those solutions and pristine films which showed a dramatic change upon film formation. With the obtained experimental results, including TAS, a possible model describing origin-dependent decay pathways was suggested in the framework of reaction kinetics. Finally, numerical simulations based on the suggested model were performed to verify the feasibility, achieving reasonable correlation with experimental observables. The results should provide deeper insights in to renewable energy strategies by using novel material classes that are compatible with flexible electronics.

Photoinduced electron transfer dynamics in dye-sensitized ZnO nanowire photoanodes

2018 ◽  
Vol 32 (19) ◽  
pp. 1840049
Author(s):  
Akihiro Furube ◽  
Takahiro Arai ◽  
Masahiro Okazaki ◽  
Shinichiro Yanagiya ◽  
Liang-Yih Chen ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Transient Absorption ◽  
Low Cost ◽  
Transient Absorption Spectroscopy ◽  
Zno Nanowire ◽  
Dye Sensitized ◽  
Femtosecond Transient Absorption ◽  
State Formula ◽  
Flexible Solar Cell

A photoanode using dye-sensitized ZnO nanowire (NW) is a good candidate for low-cost, colorful, light-weight and flexible solar cell material. We have synthesized a ZnO NW anode and a ZnO nanowire–nanoparticle (NWNP) anode, in which ZnO nanoparticles (NPs) are decollated on the surface of NWs. Photo-induced electron transfer dynamics from the excited state of sensitizer dye (D149) to the conduction band of ZnO NW and ZnO NWNP was clarified using femtosecond transient absorption spectroscopy. The decay of the single excited state ([Formula: see text]) of D149 was faster in ZnO NW than that of ZnO NWNP, indicating that NW is more suitable as an efficient electron acceptor.

scholarly journals Trap State and Charge Recombination in Nanocrystalline Passivized Conductive and Photoelectrode Interface of Dye-Sensitized Solar Cell

Coatings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 284 ◽  
Author(s):  
Siti Nur Azella Zaine ◽  
Norani Muti Mohamed ◽  
Mehboob Khatani ◽  
Adel Eskandar Samsudin ◽  
Muhammad Umair Shahid
Keyword(s):  
High Performance ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Open Circuit ◽  
Passivation Layer ◽  
Electron Recombination ◽  
Nanocrystalline Tio2 ◽  
Photovoltaic Properties ◽  
Dye Sensitized ◽  
Overall Performance

The dynamic competition between electron generation and recombination was found to be a bottleneck restricting the development of high-performance dye-sensitized solar cells (DSSCs). Introducing a passivation layer on the surface of the TiO2 photoelectrode material plays a crucial role in separating the charge by preventing the recombination of photogenerated electrons with the oxidized species. This study aims to understand in detail the kinetics of the electron recombination process of a DSSC fabricated with a conductive substrate and photoelectrode film, both passivized with a layer of nanocrystalline TiO2. Interestingly, the coating, which acted as a passivation layer, suppressed the back-electron transfer and improved the overall performance of the integrated DSSC. The passivation layer reduced the exposed site of the fluorine-doped tin oxide (FTO)–electrolyte interface, thereby reducing the dark current phenomenon. In addition, the presence of the passivation layer reduced the rate of electron recombination related to the surface state recombination, as well as the trapping/de-trapping phenomenon. The photovoltaic properties of the nanocrystalline-coated DSSC, such as short-circuit current, open-circuit voltage, and fill factor, showed significant improvement compared to the un-coated photoelectrode film. The overall performance efficiency improved by about 22% compared to the un-coated photoelectrode-based DSSC.

scholarly journals Hole injection dynamics from two structurally related Ru–bipyridine complexes into NiOx is determined by the substitution pattern of the ligands

2015 ◽  
Vol 17 (12) ◽  
pp. 7823-7830 ◽  
Author(s):  
Maximilian Bräutigam ◽  
Joachim Kübel ◽  
Martin Schulz ◽  
Johannes G. Vos ◽  
Benjamin Dietzek
Keyword(s):  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
The Other ◽  
Transient Absorption Spectroscopy ◽  
Hole Injection ◽  
Substitution Pattern ◽  
Dye Sensitized

Two chemically very similar Ru–bipyridine dyes were grafted onto NiOx and the dye-sensitized surfaces were investigated with transient absorption spectroscopy. One facilitates hole injection, the other one does not.

Oxygen diffusion dynamics in organic semiconductor films

2015 ◽  
Vol 3 (39) ◽  
pp. 10079-10084 ◽  
Author(s):  
Safa Shoaee ◽  
James R. Durrant
Keyword(s):  
Excited States ◽  
Absorption Spectroscopy ◽  
Organic Semiconductor ◽  
Oxygen Diffusion ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Semiconductor Films ◽  
Diffusion Dynamics ◽  
Kinetics Of

Transient absorption spectroscopy is commonly used to probe the yield and kinetics of excited states of materials.

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