Optimizing boron nitride nanostructures using femtosecond laser ablation for enhanced material properties

International Journal of Modern Physics B


Formation of WO3/MoS2/rGO composite prepared by integration of pulse laser ablation and hydrothermal method to enhance optical and photocatalytic activity


Superior photocatalytic properties of WO3/GO/Ag nanocomposite produced bylaser ablation andhydrothermal method

Journal of Materials Science: Materials in Electronics


Laser-ablation synthesis of novel tungsten disulfide nanostructures in liquid and their charge transfer dynamics with gold nanoparticles

Photochemical & Photobiological Sciences


Enhanced Photocatalytic Activity of TiO2/Au/TiO2/Au Stacked Nanostructures Synthesized via Sputtering and Subsequent Annealing


Synthesis of naphthalene-fused imidazo[1,2-a]pyridinium salts showing green luminescence with high quantum yields and large Stokes shift

We have synthesized naphthalene-fused imidazo[1,2-a]pyridines by a novel electrophilic iodocyclization of 2-alkynyl-3-arylimidazo[1,2-a]pyridines. Notably, their quaternized salts exhibited green emission with unexpectedly high quantum yields and mega-large Stokes shift and were successfully used for mitochondrial imaging.


Improved photocatalytic activities of TiO2/MoO3/Au nanocomposite prepared by hydrothermal method


Laser ablation synthesis of BiOCl/Ag/WO3 nanocomposite to evaluate its photocatalysis performance


Surface-Enhanced Raman Scattering from Tungsten Disulfide Nanosheets Attached to Gold Nanoparticle Array Substrates


Enhancement of Visible Light Response of TiO2 Photocatalyst by 3D-Deposited Ag Nanowires and Its Charge Separation Mechanism

In 3D-deposited AgNW/TiO2, which is prepared by spray-applying titanium dioxide suspension to deposited silver nanowire sheets, the synergistic effects of increased crossing points of AgNWs to enhance localized surface plasmon resonance excitation and longer-lived electrons in the conduction band of TiO2 generated by plasmon-induced charge transfer have successfully resulted in photocatalytic activity in the visible light range. We have developed photocatalytic sheets in which TiO2 particles are uniformly attached to 3D-deposited AgNWs. Regarding the prepared sheet, it was confirmed that TiO2 was indeed well adhered to the AgNWs, and electron transfer was efficient at the interface. This sheet solves the problem that the response wavelength range of the photocatalytic reaction using TiO2 is only in the ultraviolet region and exhibits sufficient photocatalytic effect in the visible light region. Transient absorption spectroscopy measurements in the diffuse reflectance configuration confirmed that the electrons of AgNWs actually move into the conduction band of TiO2 under visible light and that the interaction is independent of the excitation light intensity, thereby extending the lifetime of the electrons.


Blue Luminescent Boron Complexes Based on N,N-Type Imidazo[1,5-a]pyridine Ligand for Mitochondrial Imaging


Visible light active ternary nanocomposite based on metal-heterojunction for photocatalysis application: A short review


Fabrication of MoO3/rGO/Au composite for increased photocatalytic degradation of methylene blue

International Journal of Modern Physics B


Enhanced electrocatalytic hydrazine oxidation on MoS2-GO nanosheets


Simulation Analysis of the Transient Absorption Spectroscopic Dynamics of Charge Recombination in a Semiconductor Attached with a Gold Nanoparticle Using Initially Variable Coordinates

Optoelectronics, Instrumentation and Data Processing


Photogenerated Carrier Dynamics of Mn2+ Doped CsPbBr3 Assembled with TiO2 Systems: Effect of Mn Doping Content

In recent years, all-inorganic perovskite materials have become an ideal choice for new thin film solar cells due to their excellent photophysical properties and have become a research hotspot. Studying the ultrafast dynamics of photo-generated carriers is of great significance for further improving the performance of such devices. In this work, we focus on the transient dynamic process of CsPbBr3/TiO2 composite systems with different Mn2+ doping contents using femtosecond transient absorption spectroscopy technology. We used singular value decomposition and global fitting to analyze the transient absorption spectra and obtained three components, which are classified as hot carrier cooling, charge transfer, and charge recombination processes, respectively. We found that the doping concentration of Mn2+ has an impact on all three processes. We think that the following two factors are responsible: one is the density of defect states and the other is the bandgap width of perovskite. As the concentration of doped Mn2+ increases, the charge transfer time constant shows a trend of initially increasing, followed by a subsequent decrease, reaching a turning point. This indicates that an appropriate amount of Mn2+ doping can effectively improve the photoelectric performance of solar cell systems. We proposed a possible charge transfer mechanism model and further elucidated the microscopic mechanism of the effect of Mn2+ doping on the interface charge transfer process of the CsPbBr3/TiO2 solar cell system.


Ternary composite WS2/GO/Au synthesized from laser ablation and hydrothermal method for photo- and electro-chemical degradation of methylene blue dye


Monte Carlo Random Walk Simulation of Transient Absorption Kinetics Using Reflectance and Absorption of Electrons at Au/TiO2 nanoparticle boundaries


Development of silver nanocubes created by pulsed laser ablation in liquid


Novel solar-light-driven Z-scheme BiOCl@WS2 nanocomposite photocatalysts for the photocatalytic removal of organic pollutants


Extending the Optical Absorption Limit of Graphitic Carbon Nitride Photocatalysts: A Review


Origin of Enhanced Overall Water Splitting Efficiency in Aluminum-Doped SrTiO3 Photocatalyst


Photocatalytic studies of tin oxide nanostructures produced by different methods


Tungsten suboxide (WO3x) petal-like nanosheets created by laser ablation method


Ultrafast timescale charge carrier dynamics in nanocomposite hematite photoelectrodes

Journal of Photochemistry and Photobiology A: Chemistry


Photoinduced interfacial electron transfer from perovskite quantum dots to molecular acceptors for solar cells


Observation of energy transfer dynamics in a phycocyanin protein crystal by utilizing femtosecond transient absorption microscopy


Observation of carrier dynamics in MoS2 thin layer by femtosecond transient absorption microscopy


Observation of electronic spectra modulation in a CH3NH3PbBr3 crystal by utilizing transient absorption microscopy


Basic aspects of gold nanoparticle photo-functionalization using oxides and 2D materials: Control of light confinement, heat-generation, and charge separation in nanospace

Although the optical properties of localized surface plasmon resonance and the relaxation processes of excited hot electrons in gold nanoparticles (AuNPs) have been well understood, the phenomena that occur when AuNPs relax on solid surfaces of semiconductors or insulators remain largely unknown. Thermal energy diffusion and electron transfer are relatively simple physical processes, but the phenomena they induce are interesting because of a variety of new application developments. In this Perspective, we introduce the fundamental aspects as well as advanced applications of several new physical phenomena induced by AuNPs-based hybrid materials with oxides or 2D materials. Localized heat can induce a great force on the surrounding medium to control mass transport, and plasmon-induced charge transfer reactions are expected to have applications in photocatalysis and solar cells. We also review increasing reports on the development of nano-optical sensors, transistors, and nano-light sources based on precisely controlled device structures utilizing AuNPs.


Photocatalytic performance under visible light of WS2/TiO2/Au synthesized by hydrothermal method


Creation of three dimensional octahedral tin oxide nanostructure produced by laser ablation in liquid


Effect of Phenolic Substituent Position in Boron Complexes of Imidazo[1,5-a]pyridine


Polymorph-Derived Diversification of Crystal Actuation by Photoisomerization and the Photothermal Effect


Unveiling charge dynamics of visible light absorbing oxysulfide for efficient overall water splitting

Oxysulfide semiconductor, YTiOS, has recently discovered its exciting potential for visible-light-induced overall water splitting, and therefore, imperatively requires the probing of unknown fundamental charge loss pathways to engineer the photoactivity enhancement. Herein, transient diffuse reflectance spectroscopy measurements are coupled with theoretical calculations to unveil the nanosecond to microsecond time range dynamics of the photogenerated charge carriers. In early nanosecond range, the pump-fluence-dependent decay dynamics of the absorption signal is originated from the bimolecular recombination of mobile charge carriers, in contrast, the power-law decay kinetics in late microsecond range is dominated by hole detrapping from exponential tail trap states of valence band. A well-calibrated theoretical model estimates various efficiency limiting material parameters like recombination rate constant, n-type doping density and tail-states parameters. Compared to metal oxides, longer effective carrier lifetime ~6 ns is demonstrated. Different design routes are proposed to realize efficiency beyond 10% for commercial solar-to-hydrogen production from oxysulfide photocatalysts.


Two-photon excitable boron complex based on tridentate imidazo[1,5-a]pyridine ligand for heavy- atom-free mitochondria-targeted photodynamic therapy


Liquid exfoliation of graphene oxide nanoribbons using chemical assisted laser ablation

International Journal of Modern Physics B


Laser assisted synthesis of WS2 nanorods by pulsed laser ablation in liquid environment


Preparation of WS2-TiO2-Au using hydrothermal synthesis for photocatalysis under visible light


Photothermally Driven High-Speed Crystal Actuation and Its Simulation

Mechanically responsive crystals have been increasingly explored, mainly based on photoisomerization. However, photoisomerization has some disadvantages for crystal actuation, such as a slow actuation speed, no actuation of thick crystals, and a narrow wavelength range. Here we report photothermally driven fast-bending actuation and simulation of a salicylideneaniline derivative crystal with an -amino substituent in enol form. Under ultraviolet (UV) light irradiation, these thin (<20 μm) crystals bent but the thick (>40 μm) crystals did not due to photoisomerization; in contrast, thick crystals bent very quickly (in several milliseconds) due to the photothermal effect, even by visible light. Finally, 500 Hz high-frequency bending was achieved by pulsed UV laser irradiation. The generated photothermal energy was estimated based on the photodynamics using femtosecond transient absorption. Photothermal bending is caused by a nonsteady temperature gradient in the thickness direction due to the heat conduction of photothermal energy generated near the crystal surface. The temperature gradient was calculated based on the one-dimensional nonsteady heat conduction equation to simulate photothermally driven crystal bending successfully. Most crystals that absorb light have their own photothermal effects. It is expected that the creation and design of actuation of almost all crystals will be possible via the photothermal effect, which cannot be realized by photoisomerization, and the potential and versatility of crystals as actuation materials will expand in the near future.

Journal of the American Chemical Society


Charge separation dynamics in In2Se3/ZnO/Au ternary system for enhanced photocatalytic degradation of methylene blue under visible light

Journal of Photochemistry and Photobiology A: Chemistry


Improvement of Propylene Epoxidation Caused by Silver Plasmon Excitation by UV-LED Irradiation on a Sodium-Modified Silver Catalyst Supported on Strontium Carbonate --- Special Issue: Catalytic Epoxidation Reaction

The effect that UV-LED irradiation exerted on a sodium-modified silver catalyst supported on strontium carbonate (Ag-Na/SrCO3) was examined during an epoxidation of propylene to pro-pylene oxide. Based on our previous study, we used Ag(56)-Na(1)/SrCO3 in this study. The num-bers in parentheses refer to the weight percentage of silver and sodium. Although this catalyst system did not contain typical photocatalysts such as titanium oxide or tungsten oxide, UV-LED irradiation of Ag(56)-Na(1)/SrCO3 resulted in an evident improvement in the selectivity and yield of propylene oxide. Such an advantageous effect of UV-LED irradiation could not be dis-cussed based on the bandgap used in photocatalysts, and, therefore, we proposed a mechanism based on the plasmon excitation of silver, which could be accomplished using the irradiation wavelength of UV-LED to produce electrons. Since the lifespan of these electrons is expected to be short, it is difficult to place them into direct contact with the gas phase of oxygen. Once the generated electrons move to SrCO3, however, the lifespan is improved, which could allow suit-able contact with oxygen in the gas phase to form active oxygen. If the oxygen is active for epoxidation as hydrogen peroxide, this could explain the improvement in activity from UV-LED irradiation.

プロピレンのプロピレンオキシドへのエポキシ化に対して炭酸ストロンチウムに担持されたナトリウム修飾銀触媒(Ag-Na/SrCO3)を用いた場合のUV-LED照射も影響を検討した．既報の結果に基づいて，この研究ではAg(56)-Na(1)/SrCO3を使用した．なお，括弧内の数字は，銀とナトリウムの重量パーセントを示す．この触媒には，酸化チタンや酸化タングステンなどの，一般的な光触媒は含まれていないが，Ag(56)-Na(1)/SrCO3触媒にUV-LEDを照射すると，酸化プロピレンの選択性と収率が明らかに向上した．このようなUV-LED照射の加速な効果は，光触媒の議論で汎用されるバンドギャップではできなかったため，UV-LEDの照射波長により発現する銀のプラズモン励起に基づくメカニズムを提案した．UV-LEDを銀のナノ粒子にい照射してプラズモン電子が生成する．これらの電子の寿命は短いと予想されるため，酸素の気相と直接接触させることは困難である．ただし，生成された電子がSrCO3に移動すると，寿命が長くなり，気相中の酸素と適切に接触して活性酸素を形成できるようになる．酸素が過酸化水素のようなエポキシ化に対して有効な活性酸素である場合，本研究で観測されたUV-LED照射による活性の改善を説明できる．


Plasmon Induced Charge Transfer Mechanism in Gold-TiO2 Nanoparticle Systems: The Size Effect of Gold Nanoparticle


In2Se3 Nanocubes as High Current Density Cold Cathode Materials


Dynamic coupling of optically evolved assembling and swarming of gold nanoparticles with photothermal local phase separation of polymer solution


Oxidative Dehydrogenation of Methane When Using TiO2- or WO3-Doped Sm2O3 in the Presence of Active Oxygen Excited with UV-LED --- Special Issue: Photocatalytic Oxidation/Ozonation Processes

There are active oxygen species that contribute to oxidative coupling or the partial oxidation during the oxidative dehydrogenation of methane when using solid oxide catalysts, and those species have not been definitively identified. In the present study, we clarify which of the active oxygen species affect the oxidative dehydrogenation of methane by employing photo-catalysts such as TiO2 or WO3, which generate active oxygen from UV-LED irradiation conditions under an oxygen flow. These photo-catalysts were studied in combination with Sm2O3, which is a methane oxidation coupling catalyst. For this purpose, we constructed a reaction system that could directly irradiate UV-LED to a solid catalyst via a normal fixed-bed continuous-flow reactor operated at atmospheric pressure. Binary catalysts prepared from TiO2 or WO3 were either supported on or kneaded with Sm2O3 in the present study. UV-LED irradiation clearly improved the partial oxidation from methane to CO and/or slightly improved the oxidative coupling route from me-thane to ethylene when binary catalysts consisting of Sm2O3 and TiO2 are used, while negligible UV-LED effects were detected when using Sm2O3 and WO3. These results indicate that with UV-LED irradiation the active oxygen of O2 from TiO2 certainly contributes to the activation of methane during the oxidative dehydrogenation of methane when using Sm2O3, while the active oxygen of H2O2 from WO3 under the same conditions afforded only negligible effects on the activation of methane.

本研究は，酸素流通下でUV-LED照射すると活性酸素を生成するTiO2やWO3などの光触媒を用いて，どのような活性酸素種がメタンの酸化脱水素に影響を与えるかという点を解決する一環として行われた．常圧固定床流通式反応装置を用い，大気圧下で直接UV-LEDを固体触媒に照射できる反応系を構築した．触媒には，メタン酸化カップリング触媒であるSm2O3とTiO2またはWO3から二元系触媒を選択し，それぞれ担持法および混練法で調製した．Sm2O3とTiO2からなる二元系触媒を使用した場合，UV-LED照射によりメタンからCOへの部分酸化が改善され，メタンからエチレンへの酸化カップリングもわずかに改善された．一方，Sm2O3とWO3からなる二元系触媒を使用した場合，UV-LED効果はほとんどなかった．UV-LED照射により，TiO2からの発生する活性酸素であるO2‒はSm2O3を使用する場合には，メタンの酸化脱水素におけるメタンの活性化に寄与するが，WO3から発生する活性酸素であるH2O2はほとんど効果を示さないと結論づけた．


Charge generation dynamics in hematite photoanodes decorated with gold nanostructures under near infrared excitation

Photochemical water splitting offers a useful solution for efficient energy conversion into hydrogen gas. Hematite has been focused on this purpose as the photoanode due to the advantages of low-cost, chemical stability, and suitable bandgap. The photocatalytic ability, however, is limited by the short-lived carriers and lack of photoresponse in the near infrared (NIR) region. As a solution, combining hematite with a noble metal can enhance the photocatalytic performance toward longer wavelength. Gold nanoparticles indicate characteristic absorption in the visible and NIR regions and photo-induced injection of electrons into the semiconductor. In this study, a hybrid material of hematite photoanodes with gold nanostructures was fabricated and the carrier dynamics under NIR excitation was elucidated by femtosecond transient absorption spectroscopy. The observed strong positive absorption under NIR excitation of Au nanorods (NRs) on the hematite anode indicated an increased electron density in hematite due to electron transfer from AuNRs, demonstrating efficient charge carrier generation in hematite by the decorated gold nanostructure.


FEMTOSECOND TRANSIENT ABSORPTION SPECTROSCOPY OF MAGHEMITE NANOPARTICLES LOADED WITH GOLD NANOPARTICLES


Effects of the solvent during the preparation of MoS2 nanoparticles by laser ablation


PMMA-BN composites incorporated with Au nanoparticle fabricated by laser ablation


Study of Heat Dissipating Material Using Boron Nitride Fabricated by Laser Ablation


Transient Absorption Spectroscopy Reveals Performance-Limiting Factors in a Narrow-Bandgap Oxysulfide La5(Ti0. 99Mg0. 01)2CuS5O6.99 Photocatalyst for H2 Generation


Femtosecond Transient Absorption Spectroscopy of Laser-ablated Graphite and Reduced Graphene Oxide for Optical Switching Behavior


Impact of Orbital Hybridization at Molecule Metal Interface on Carrier Dynamics


Evaluation of carrier lifetime and photocatalytic properties of annealed ZnS/TiO2 nanocomposite


A study on the field emission properties of Bi2Se3 nanostructures prepared by laser ablation


Field effect transistor behavior of Bi2Se3 nanostructure prepared by laser ablation


Effect of nanosecond and femtosecond pulse laser on the formation of WS2 nanostructures and field emission characteristics


Steady-state and time-resolved optical properties of multilayer film of titanium dioxide sandwiched by gold nanoparticles and gold thin film

We proposed metal insulator (MI) and metal insulator metal (MIM) structures of titanium dioxide (TiO2) sandwiched by gold nanoparticles (AuNPs) layer and gold sputtered thin film (only for the MIM film) to couple localized plasmon mode of AuNP with multi reflection mode and/or cavity resonator mode of TiO2. The optical extinctions of MI and MIM with differing TiO2 thickness were studied theoretically by finite element method simulation and experimentally by optical spectrometry. The extinction peaks of MI and MIM shifted by exchanging the surrounding medium from air to TiO2. The interference of TiO2 in MI structure also affected the extinction spectra showing the oscillation along the spectrum of AuNP in TiO2. Then, the extinction degree of MIM was higher than that of MI because of the coupling between cavity resonance mode with localized plasmon mode and interband transition in AuNPs. In addition, the cross section of MI and MIM films were observed by scanning electron microscopy. The surface of thinner film was rough because TiO2 heterogeneously grew from AuNP. The irregular growth of TiO2 might have induced the wide range extinction in 300 2500 nm after Au thin film deposition. The transient absorption spectra using a femtosecond laser were also carried out under the condition of 800 nm for excitation laser and 950 nm for probe laser. The long lived electron (∼1 ns) was observed in thick MIM film as a result of hot electron transfer from the gold nanostructure in the film.

ChemNanoMat : Chemistry of Nanomaterials for Energy, Biology and More


Origin of the overall water splitting activity of Ta3N5 revealed by ultrafast transient absorption spectroscopy


Flow-Induced Transport via Optical Heating of a Single Gold Nanoparticle


Clear and transparent nanocrystals for infrared-responsive carrier transfer

Infrared-light-induced carrier transfer is a key technology for 'invisible' optical devices for information communication systems and energy devices. However, clear and colourless photo-induced carrier transfer has not yet been demonstrated in the field of photochemistry, to the best of our knowledge. Here, we resolve this problem by employing short-wavelength-infrared (1400-4000 nm) localized surface plasmon resonance-induced electron injection from indium tin oxide nanocrystals to transparent metal oxides. The time-resolved infrared measurements visualize the dynamics of the carrier in this invisible system. Selective excitation of localized surface plasmon resonances causes hot electron injection with high efficiency (33%) and long-lived charge separation (~ 2-200 μs). We anticipate our study not only provides a breakthrough for plasmonic carrier transfer systems but may also stimulate the invention of state-of-the-art invisible optical devices.


Revealing the role of the Rh valence state, La doping level and Ru cocatalyst in determining the H2 evolution efficiency in doped SrTiO3 photocatalysts


Photothermal dynamics of micro-glass beads coated with gold nanoparticles in water: fine bubble generation and fluid-induced laser trapping


Photoinduced electron transfer dynamics in dye-sensitized ZnO nanowire photoanodes

International Journal of Modern Physics B


Formation of WS2 nanosheets and its field emission studies


Production of boron nitride nanostructures using nanosecond laser ablation in acetone


Enhancement in field emission of MoS2 nanosheets prepared in water using laser ablation method


Field emission properties of laser ablated multi-walled carbon nanotubes


Electron Transfer Dynamics and Yield from Gold Nanoparticle to Different Semiconductors Induced by Plasmon Band Excitation


Plate-Like Sm2Ti2S2O5 Particles Prepared by a Flux-Assisted One-Step Synthesis for the Evolution of O2 from Aqueous Solutions by Both Photocatalytic and Photoelectrochemical Reactions


Insight into plasmonic hot-electron transfer and plasmon molecular drive: New dimensions in energy conversion and nanofabrication

Localized surface plasmon resonance (LSPR) of plasmonic nanoparticles and nanostructures has attracted wide attention because the nanoparticles exhibit a strong near-field enhancement through interaction with visible light, enabling subwavelength optics and sensing at the single-molecule level. The extremely fast LSPR decays have raised doubts that such nanoparticles have use in photochemistry and energy storage. Recent studies have demonstrated the capability of such plasmonic systems in producing LSPR-induced hot electrons that are useful in energy conversion and storage when combined with electron-accepting semiconductors. Due to the femtosecond timescale, hot-electron transfer is under intense investigation to promote ongoing applications in photovoltaics and photocatalysis. Concurrently, hot-electron decay results in photothermal responses or plasmonic heating. Importantly, this heating has received renewed interest in photothermal manipulation, despite the developments in optical manipulation using optical forces to move and position nanoparticles and molecules guided by plasmonic nanostructures. To realize plasmonic heating-based manipulation, photothermally generated flows, such as thermophoresis, the Marangoni effect and thermal convection, are exploited. Plasmon-enhanced optical tweezers together with plasmon-induced heating show potential as an ultimate bottom-up method for fabricating nanomaterials. We review recent progress in two fascinating areas: solar energy conversion through interfacial electron transfer in gold-semiconductor composite materials and plasmon-induced nanofabrication.


Rational Interpretation of Correlated Kinetics of Mobile and Trapped Charge Carriers: Analysis of Ultrafast Carrier Dynamics in BiVO4


Evidence and mechanism of efficient thermally activated delayed fluorescence promoted by delocalized excited states


Direct Aqueous Dispersion of Carbon Nanotubes Using Nanoparticle-Formed Fullerenes and Self-Assembled Formation of p/n Heterojunctions with Polythiophene


Synthesis, crystal structure, and photophysical properties of 2, 9-disubstituted peropyrene derivatives


Photoelectron detection from transient species in organic semiconducting thin films by dual laser pulse irradiation


Enhancement of Charge Separation and Hydrogen Evolution on Particulate La5Ti2CuS5O7 Photocathodes by Surface Modification

Particulate La5Ti2CuS5O7 (LTC) photocathodes prepared by particle transfer show a positive onset potential of 0.9 V vs RHE for the photocathodic current in photoelectrochemical (PEC) H2 evolution. However, the low photocathodic current imposes a ceiling on the solar-to-hydrogen energy conversion efficiency of PEC cells based on LTC photocathodes. To improve the photocurrent, in this work, the surface of Mg-doped LTC photocathodes was modified with TiO2, Nb2O5, and Ta2O5 by radio frequency reactive magnetron sputtering. The photocurrent of the modified Mg-doped LTC photocathodes was doubled because these oxides formed type-II heterojunctions and extended the lifetimes of photogenerated charge carriers. The enhanced photocathodic current was attributed to hydrogen evolution at a positive potential of +0.7 V vs RHE. This work opens up possibilities for improving PEC hydrogen evolution on particulate photocathodes based on surface oxide modifications and also highlights the importance of the band gap alignment.

The Journal of Physical Chemistry Letters


Charge Generation and Recombination in Diketopyrrolopyrrole Polymer: Fullerene Bulk Heterojunctions Studied by Transient Absorption and Time-Resolved Microwave Conductivity


Rationalizing long-lived photo-excited carriers in photocatalyst (La5Ti2CuS5O7) in terms of one-dimensional carrier transport


Halogenated (F, Cl, Br, or I) Diphenylhexatrienes: Crystal Structures, Fluorescence Spectroscopic Properties, and Quantum Chemical Calculations


Remarkable Dependence of the Final Charge Separation Efficiency on the Donor-Acceptor Interaction in Photoinduced Electron Transfer

The unprecedented dependence of final charge separation efficiency as a function of donor-acceptor interaction in covalently-linked molecules with a rectilinear rigid oligo-p-xylene bridge has been observed. Optimization of the donor-acceptor electronic coupling remarkably inhibits the undesirable rapid decay of the singlet charge-separated state to the ground state, yielding the final long-lived, triplet charge-separated state with circa 100 % efficiency. This finding is extremely useful for the rational design of artificial photosynthesis and organic photovoltaic cells toward efficient solar energy conversion.


Theoretical limit of power conversion efficiency for organic and hybrid halide perovskite photovoltaics


Photoanodic and photocathodic behaviour of La5Ti2CuS5O7 electrodes in the water splitting reaction


Driving Force Dependence of Electron Transfer Kinetics and Yield in Low-Band-Gap Polymer Donor-Acceptor Organic Photovoltaic Blends


In situ picosecond transient diffuse reflectance spectroscopy of opaque TiO2 systems under microwave irradiation and influence of oxygen vacancies on the UV-driven/microwave-assisted TiO2 photocatalysis

Journal of Materials Chemistry. C, Materials for Optical and Electronic Devices


Kinetics of Distance-Dependent Recombination between Geminate Charge Carriers by Diffusion under Coulomb Interaction


Modulation of Electron Injection Dynamics of Ru-Based Dye/TiO2 System in the Presence of Three Different Organic Solvents: Role of Solvent Dipole Moment and Donor Number

In the present work, femtosecond transient absorption spectroscopy (fs-TAS) has been employed to investigate the electron injection efficiency (EIE) both from the singlet and triplet excited states of a well-known ruthenium dye (N719) to the conduction band (CB) of nanostructured TiO(2) in presence of three different organic solvents [γ-butylactone (GBL), 3-methoxypropionitrile (MPN), and dimethylformamide (DMF)] with different donor numbers (DNs) and dipole moments (DMs). The DM and DN of a solvent modulates the CB edge energy of TiO(2), and this effect reflects well in the fs-TAS results, which shows an EIE trend following the order GBL≥MPN≫DMF, that is, highest in GBL and lowest in DMF solvent environments. Fs-TAS results indicate a lower contribution of electron injection from both the singlet and triplet states in DMF, for which the dominant adsorption of DMF molecules on the TiO(2) surface seems to play an important role in the mechanism.


Trapped State Sensitive Kinetics in LaTiO2N Solid Photocatalyst with and without Cocatalyst Loading

In addition to the process of photogeneration of electrons and holes in photocatalyst materials, the competitive process of trapping of these charge carriers by existing defects, which can both enhance the photocatalytic activity by promoting electron-hole separation or can deteriorate the activity by serving as recombination centers, is also very crucial to the overall performance of the photocatalyst. In this work, using femtosecond diffuse reflectance spectroscopy we have provided evidence for the existence of energetically distributed trapped states in visible-light responsive solid photocatalyst powder material LaTiO2N (LTON). We observe trapped state sensitive kinetics in bare-LTON. CoOx cocatalyst loading (2 wt % CoOx-LTON) shows effect on the kinetics only when presence of excess energy (for above bandgap excitation) results in the generation of surface carriers. Thus, the kinetics show appreciable excitation wavelength dependence, and the experimental results obtained for different λexc have been rationalized on this basis. In an earlier work by Domen and co-workers, the optimized CoOx/LTON has been reported to exhibit a high quantum efficiency of 27.1 ± 2.6% at 440 nm, the highest reported for this class of photocatalysts (J. Am. Chem. Soc. 2012, 134, 8348-8351). In the present work, the mechanism is addressed in terms of picosecond charge carrier dynamics.

Journal of the American Chemical Society


Electron injection dynamics in dye-sensitized semiconductor nanocrystalline films


Electron injection efficiency in dye-sensitized solar cells

Journal of Photochemistry and Photobiology C: Photochemistry Reviews


Dye Aggregation Effect on Interfacial Electron-Transfer Dynamics in Zinc Phthalocyanine-Sensitized Solar Cells


Strongest pi-metal orbital coupling in a porphyrin/gold cluster system


Spectroscopic Characterization of Nanohybrids Consisting of Single-walled Carbon Nanotubes and Fullerodendron

Fullerenes Nanotubes and Carbon Nanostructures


Excited-state dynamics in diketopyrrolopyrrole-based copolymer for organic photovoltaics investigated by transient optical spectroscopy


Synthesis of blue luminescent boron complex of 3-(o-hydroxyphenyl)imidazo[1,5-a]pyridine

Proceedings of the LED General Forum 2022 Tokushima


Photodimers of symmetrical tetraaryl[3]cumulenes showing crystallization-induced emission enhancement nature


Role of intermediate state in the excited state dynamics of highly efficient TADF molecules


Revealing the Excitedstate Dynamics of Thermally Activated Delayed Flourescence Molecules by using Transient Absorption Spectrospy

SID Symposium Digest of Technical Papers