Despite the excellent optoelectronic properties of halide perovskites, ionic and electronic defects adversely affect stability durability perovskites their devices. These defects, intrinsic or produced by environmental factors such as oxygen, moisture, light, not only cause chemical reactions that disintegrate structure but also induce undesired photoluminescence blinking to perovskite quantum dots nanocrystals. Blinking is caused nonradiative Auger processes in photocharged Herein, we find...

Both the photochemical kinetics and spatial reaction dynamics in single crystals could be rationalized terms of difference cooperativity reactions that relates magnitude conformational change required for reaction.

Self-oscillation of polymer chains in an aqueous solution has been achieved. The ruthenium catalyst for the Belousov−Zhabotinsky reaction was polymerized by using N-isopropylacrylamide and dissolved into containing BZ substrates. Periodical soluble−insoluble changes chain were spontaneously induced reaction. conformational oscillations measured as optical transmittance solution. This is first report that rhythmical reversible are realized under constant homogeneous conditions. transducing...

種々の側鎖構造をもつN-置換アクリルアミド誘導体, N-置換メタクリルアミド誘導体, ならびにN, N-ジ置換アクリルアミド誘導体を合成し, これらを重合させて得られる高分子について, それぞれの一次構造と水に対する溶解特性の関係を比較した. これら高分子は, 側鎖アルキル基の鎖長の増加につれて 「水溶性」 から 「低温で水溶性でかつ高温で水不溶性」, 「水不溶性」 へと変化する. 「低温で水溶性でかつ高温で水不溶性を示す」 高分子の系では, その水溶液を加熱するときは相転移に相当する曇点現象が観測され, その相転移温度はそれぞれの高分子の一次構造に依存することが実証された. このようにして側鎖アルキル基の形状を含めた鎖長の構造を変えることにより, 転移温度が5℃から72℃までの範囲にみられる種々の高分子が得られた, メタクリルアミド系高分子水溶液の転移温度は, アクリルアミド系高分子のそれと比べほぼ規則的に7~15℃高温側に現れることがわかった.

Fluorescence correlation spectroscopy (FCS) was applied to the quantitative evaluation of local heating in small domains <1 μm solutions under laser trapping condition presence a near-infrared (NIR) beam at 1064 nm. On basis translational diffusion coefficient fluorescent molecules obtained by FCS, relationship between temperature rise and incident NIR power, ΔT/ΔP, were determined be 62 ± 6, 49 7, 23 1 deg K/W ethylene glycol, ethanol, water, respectively, while no remarkable increase...

One-color control of colorization/decolorization reactions diarylethene molecules was attained by using nonresonant high-order multiphoton absorption processes with a near-infrared (NIR) femtosecond laser pulse at 1.28 μm 35 fs full width half-maximum (fwhm). The intensity rather weak (<1 nJ/pulse) can induce the simultaneous three-photon leading to colorization, while much weaker induces two-photon resulting in decolorization. spatial patterning concomitant higher-order also demonstrated.

The use of localized surface plasmons (LSPs) for highly sensitive biosensors has already been investigated, and they are currently being applied the optical manipulation small nanoparticles. objective this work was trapping λ-DNA on a metallic nanostructure with femtosecond-pulsed (fs) laser irradiation. Continuous-wave irradiation, which is generally used plasmon excitation, not only increased electromagnetic field intensity but also generated heat around nanostructure, causing DNA to...

Photoswitchable turn-on mode fluorescent molecules have been so far successfully used in super-resolution fluorescence microscopies. Here, we report on photoswitching of 1,2-bis(2-ethyl-6-phenyl-1-benzothiophene-1,1-dioxide-3-yl)perfluorocyclopentene (1) by irradiation with single-wavelength visible (420 nm < λ 470 nm) light, the wavelength which is longer than 0-0 transition open-ring isomer 1a, without UV light excitation. By absorbing very weak hot bands or Urbach tails 1a underwent a...

Gold nanoparticles (Au NPs) efficiently convert incident light into heat under the resonant conditions of localized surface plasmon. Controlling mass transfer through plasmonic heating Au NPs has potential applications such as manipulation and fabrication within a small space. Here, we describe formation stationary microbubbles subsequent fluid convection induced by CW laser in water. Stationary bubbles about 1–20 μm diameter were produced irradiating individual with laser. Spatial profiles...

We demonstrated one-colour control of activation, excitation and deactivation a fluorescent diarylethene derivative by using 532 nm CW laser at weak output power.

A method to fix single gold nanoparticles on glass substrate was demonstrated in solution at room temperature by utilizing focused intense laser beams. nanoparticle of 80 nm optically trapped and manipulated a surface substrate, then fixed it irradiation with ultraviolet (UV) light. Suitable fluence range for the fixation determined be 32–60 mJ/cm2, above which individual were fragmented several smaller fragments 10 40 nm. The mechanism is discussed view pulsed-laser-induced transient elevation.

The photodissociation dynamics of a hexaarylbiimidazole (HABI) derivative with two pyrenyl groups was investigated by time-resolved transient absorption spectroscopy and fluorescence measurements. Transient revealed that took place in the wide time region <100 fs to 10 ns. On other hand, profiles showed dynamic red shift ps. apparent dispersive process attributed increase interaction between moiety excited state ground state, resulting gradual activation energy for crossing attractive...

Local molecular states and biological materials in small spaces ranging from the microscale to nanoscale can be modulated for medical applications using photothermal effect (PTE). However, there have been only a few reports on exploiting collective phenomena of localized surface plasmons (LSPs) increase amount light-induced heat control material generation macroscopic assembled structures. Here, we clarify that microbeads covered with vast number Ag nanoparticles induce large PTE generate...

Optical trapping of flexible polymer chains to a metallic nanostructured surface was explored by microscopic imaging and confocal fluorescence spectroscopy. A fluorescence-labeled poly(N-isopropylacrylamide) targeted, being representative thermo-responsive polymer. Upon resonant plasmonic excitation, it clearly observed that polymers were assembled into the excitation area form molecular assemblies. Simultaneously, from obviously intensified, indicating an increase in number at area. The...

Triphenylboranes planarized with three methylene bridges exhibited dual fluorescence bands around 340 and 400 nm despite their structural constraint. To elucidate the origin, excited state dynamics were experimentally theoretically studied. The measurements of lifetimes transient absorption spectra indicated that triphenylboranes adopt two local minimum structures in lowest-energy singlet (S1) state. TD-DFT potential energy surface S1 possesses at least associated a planar bowl-shaped...

Stepwise two-photon excitations have been attracting much interest because of their lower power thresholds compared with simultaneous processes and some stepwise can be initiated by a weak incoherent excitation light source. Here we apply optical to the photochromic bridged imidazole dimer, whose solution instantly changes color upon UV irradiation quickly reverts initial thermally at room temperature. We synthesized zinc tetraphenylporphyrin (ZnTPP)-substituted wide ranges time-resolved...

Aqueous redox polymerization using a surfactant was studied to prepare submicrometer-sized polyelectrolyte gel particles from monomer solution containing N-isopropylacrylamide (NIPA), N,N'-methylenebisacrylamide (Bis), and acrylic acid (AAc) or 1-vinylimidazole (VI). Sodium dodecylbenzenesulfonate ammonium persulfate were used as the initiator, respectively. The purified via dialysis characterized by photon correlation spectroscopy. Since AAc VI contents of solutions controllable within 0−30...

A highly efficient natural light-harvesting antenna has a ring-like structure consisting of dye molecules whose absorption band changes through selective evolutionary processes driven by external stimuli, i.e., sunlight depending on its territory and thermal fluctuations. Inspired this fact, here, we experimentally theoretically demonstrate the assembling arrangements many silver nanorods with particular shapes orientations onto substrate light-induced force doughnut beams different colours...

A new fluorescent photochromic diarylethene that can be activated by irradiation with 405 nm light was synthesized. The turn-on mode switching of fluorescence visible is favorable for application to biological systems. quantum yield the photogenerated closed-ring isomer as high 0.8 in less or medium polar solvents, and even acetonitrile higher than 0.6.

Photoreactivity in crystal is one of the essential properties for creating photo-functional crystalline materials. This study explores impact dihedral angle aryl groups on photocyclization reactivity...

We have utilized an upconverting nanoparticle (UCNP) with thulium (Tm) ions as emitters and Ytterbium (Yb) sensitizers (TmUCNP) for nanometric photoexcitation of a film conjugated polymer, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV). The TmUCNPs surrounded by thin layer MEH-PPV were photoexcited at 976 nm using continuous-wave (CW) near-infrared laser. NIR light was selectively absorbed the sensitizer TmUCNPs, leading to formation submillisecond-lifetime excited...

We have utilized an upconverting nanoparticle (UCNP) with thulium (Tm) ions as emitters and Ytterbium (Yb) sensitizers (TmUCNP) for nanometric photoexcitation of a film conjugated polymer, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV). The TmUCNPs surrounded by thin layer MEH-PPV were photoexcited at 976 nm using continuous-wave (CW) near-infrared laser. NIR light was selectively absorbed the sensitizer TmUCNPs, leading to formation submillisecond-lifetime excited...