Time-resolved fluorescence measurements of graphene oxide in water show multiexponential decay kinetics ranging from 1 ps to 2 ns. Electron-hole recombination the bottom conduction band and nearby localized states wide-range valance is suggested as origin fluorescence. Excitation wavelength dependence was caused by relative intensity changes few emission species. By introducing molecular orbital concept, dominant found originate electronic transitions among/between non-oxidized carbon...

The dynamics of photoexcited lead-free perovskite films, CH3NH3SnI3, were studied using broadband transient absorption and time-resolved fluorescence spectroscopy. Similar to its lead analogue CH3NH3PbI3, we show that free carrier (electrons holes) recombination is also the dominant relaxation pathway in CH3NH3SnI3 films. slow hot time 0.5 ps. Long diffusion lengths for electrons (279 ± 88 nm) holes (193 46 obtained from quenching measurements. We SnF2 doping film effectively increases...

Metal-organic frameworks (MOFs) MIL-88A hexagonal microrods as a new photocatalyst show an active performance for methylene blue (MB) dye decolorization using visible light. MB over the follows first-order kinetics. The addition of H2O2 electron acceptor can markedly enhance photocatalytic decoloration MIL-88A. Moreover, showed very stable activity after four consecutive usages. Owing to advantages light response, low cost and abundance in nature, this MOF would have great potential...

In this work, nanorods of CdS, CdSe, and CdSeS are deposited by chemical vapor deposition on TiO2 nanorod arrays, the photoelectrochemical (PEC) performance heterostructures is studied comprehensively. It found that nanorods-shaped CdS superior to nanoparticles as photosensitizer. The difference in photosensitizing effect among alloy using optical electrochemical techniques. energy levels these heterostructure photoelectrodes constructed based X-ray photoelectron spectroscopy (XPS) diffused...

Hybrid halide perovskites are emerging semiconducting materials, with a diverse set of remarkable optoelectronic properties. Besides the widely studied three-dimensional (3D) perovskites, two-dimensional (2D) show significant potential as photovoltaic (PV) active layers while exhibiting high moisture resistance. Here, we report two series new 2D perovskite solid solutions: (HA)Pb1–xSnxI4 and (BZA)2Pb1–xSnxI4 (x = 1, 0.75, 0.5, 0.25, 0), where HA stands for organic spacer histammonium BZA...

The excited state dynamics of rubrene in solution and the single crystal were studied by femtosecond pump–probe spectroscopy under various excitation conditions. Singlet fission was demonstrated to play a predominant role relaxation contrast solution. Upon 500 nm excitation, triplet excitons form on picosecond time scale via from lowest singlet state. 250 upper states is observed within 200 fs.

Organic–inorganic perovskite photovoltaics are an emerging solar technology. Developing materials and processing techniques that can be implemented in large‐scale manufacturing is extremely important for realizing the potential of commercialization. Here we report a hot‐casting process with controlled Cl − incorporation which enables high stability power‐conversion‐efficiencies (PCEs) 18.2% small area (0.09 cm 2 ) 15.4% large‐area (≈1 single cells. The enhanced performance versus tri‐iodide...

Singlet fission (SF) in polycrystalline thin films of four 3,6-bis(thiophen-2-yl)diketopyrrolopyrrole (TDPP) chromophores with methyl (Me), n-hexyl (C6), triethylene glycol (TEG), and 2-ethylhexyl (EH) substituents at the 2,5-positions is found to involve an intermediate excimer-like state. The different yield distinct intermolecular packing geometries, resulting variable charge transfer (CT) interactions solid. SF from excimer state Me, C6, TEG, EH takes place τSF = 22, 336, 195, 1200 ps,...

Singlet exciton fission (SF) in organic chromophore assemblies results the conversion of one singlet (S1) into two triplet excitons (T1), provided that overall process is exoergic, i.e., E(S1) > 2E(T1). We report on SF thin polycrystalline films terrylene-3,4:11,12-bis(dicarboximide) (TDI) derivatives 1 and 2, which crystallize distinct π-stacked structures. Femtosecond transient absorption spectroscopy (fsTA) reveals a charge-transfer state preceding 190% T1 yield 1, where TDI molecules are...

Abstract The realization of whispering gallery mode (WGM) lasing in polymer fibers is hindered by an appropriate method to dissolve the and gain material. In this work, microfibers fabricated directly drawing from a dye doped solution are exhibited as high quality microlasers microsensors. Multi‐mode even single‐mode observed fiber under optical pumping at room temperature. linewidth narrower than 0.09 nm. mechanism unambiguously verified comprehensive spectroscopic analysis ascribed WGMs....

The thermal decomposition products and kinetics of two typical organic–inorganic halide perovskites, CH3NH3PbI3 (MAPbI3) HC(NH2)2PbI3 (FAPbI3), were investigated via simultaneous thermogravimetric analysis coupled with Fourier transform infrared spectroscopy. NH3 CH3I verified as the major gases MAPbI3. Furthermore, for first time, methane (CH4) was observed a degradation product MAPbI3 at elevated temperatures. In contrast to conventional wisdom, (HCN)3 (trimerized HCN) demonstrated gaseous...

Owing to their ability act as light-harvesting scaffolds, porphyrin-containing metal-organic frameworks (MOFs) are in the forefront of research on application highly ordered molecular materials problems solar-energy conversion. In this work, solvent-assisted linker exchange (SALE) is performed a pillared paddlewheel porphyrin containing MOF thin film collapse 3D framework 2D framework. The change dimensionality confirmed by decrease thickness, magnitude which agreement with crystallographic...

Abstract Light‐emitting diodes (LEDs) based on lead halide perovskites demonstrate outstanding optoelectronic properties and are strong competitors for display lighting applications. While previous perovskite LEDs mainly produced via solution processing, here an all‐vacuum processing method is employed to construct CsPbBr 3 because vacuum exhibits high reliability easy integration with existing OLED facilities mass production. The high‐throughput combinatorial strategies further adopted...

The Cu surface with a dual-scale roughness has been prepared via facile solution-phase etching route by the H2O2/HCl etchants. selective of high-energy {110} facets occurs at an ultralow rate redox reaction. resultant is composed many polyhedral microprotrusions and nanomastoids on microprotrusions, exhibiting binary micro/nanostructures. After hydrophobization, exhibits water contact angle 170° sliding ∼2.8° for 5 μL droplet. combination low energy adsorbed stearic acid accounts...

A simple strategy is developed to prepare eccentrically or homogeneously loaded nanoparticles (NPs) using poly (DL-lactide-co-glycolide) (PLGA) as the encapsulation matrix in presence of different amounts polyvinyl alcohol (PVA) emulsifier. Using 2,3-bis(4-(phenyl(4-(1,2,2-triphenylvinyl)-phenyl)amino)-phenyl)-fumaronitrile (TPETPAFN), a fluorogen with aggregation-induced emission (AIE) characteristics, an example, PLGA NPs show increased fluorescence quantum yields (QYs) compared ones....

Near-infrared (NIR) fluorescence signals are highly desirable to achieve high resolution in biological imaging. To obtain NIR emission with brightness, fluorescent nanoparticles (NPs) synthesized by co-encapsulation of 2,3-bis(4-(phenyl(4-(1,2,2-triphenylvinyl)phenylamino)phenyl)fumaronitrile (TPETPAFN), a luminogen aggregation-induced (AIE) characteristics, and fluorogen silicon 2,3-naphthalocyanine bis(trihexylsilyloxide) (NIR775) using...

Abstract Upconversion rare‐earth nanomaterials (URENs) possess highly efficient near‐infrared (NIR), e.g., 980 nm, laser absorption and unique energy upconversion capabilities. On the other hand, graphene its derivatives, such as oxide (GO), show excellent performance in optical limiting (OL); however, wavelengths of currently used lasers for OL studies mainly focus on either 532 or 1064 nm. To design new‐generation materials working at regions, NIR, a novel nanocomposites, GO–URENs, which...

Large two-photon absorption cross section and high fluorescence quantum yield (QY) of a fluorescent probe is highly desirable to achieve resolution in excited imaging. Taking poly(9,9-dihexylfluorene-alt-2,1,3-benzothiadiazole) (PFBT) as an example, we report one-step approach synthesize PFBT loaded nanoparticles (NPs) with both large QY aqueous media through micelle silica coprotection strategy. The NPs show 1085 GM at 810 nm based on polymer chain concentration emission maximum 545 75%....

We have studied fluorescence in rubrene single crystals by use of up-conversion, anisotropy, and temperature-dependent time-resolved techniques. Thermally activated singlet fission was demonstrated to play an important role the quenching two intrinsic bands, 565 610 nm. At low temperatures, is suppressed while another process, namely energy trapping, becomes pronounced. The 650 nm originates from hole trap states located 0.27 eV above valence band.

Perylene forms three binary compounds with TCNQ. Using a physical vapor transport (PVT) method, mixtures of P1T1 (perylene1–TCNQ1), P2T1 (perylene2–TCNQ1), and P3T1 (perylene3–TCNQ1) crystals can be grown simultaneously. Solution-grown exhibit stoichiometry that depends on the solvent used not initial perylene TCNQ: only single were from toluene, P3T1, benzene. Precipitation–dissolution theory was employed to explain this phenomenon. We found is less soluble than in which resulted its...

Superior optical limiting (OL) characteristics and mechanisms are explored in a novel nanocomposite made from graphene oxide (GO) NaYF4:Yb3+/Er3+ nanoparticles via covalent chemical bonding. Due to the synergistic effect of enhanced nonlinear scattering, two-photon absorption, efficient energy transfer between GO, displays dramatically improved OL effects compared either GO or nanoparticles, making it very promising material for practical devices.

Crystalline selenium (c-Se) is a direct band gap semiconductor and has been developed for detector applications more than 30 years. While most advances have made using vacuum deposition processes, it remains challenge to prepare efficient c-Se devices directly from solution. We demonstrate simple solution process leading uniform high-crystallinity films under ambient conditions. A combination of ethylenediamine (EDA) hydrazine solvents was found be effective in dissolving powder forming...