A multiple coupling approach to produce high-performance SERS substrates

In this work, large area gold-nanoparticle-cluster pillar array with a gold mirror as high-performance SERS substrate was facilely fabricated by combined use of nanosphere lithography and self-assembly approach.     

Heterostructure of Ta3N5 nanorods and CaTaO2N nanosheets fabricated using a precursor template to boost water splitting under visible light

Fabrication of heterostructure composed of one-dimensional (1D) and 2D semiconductors has inspired extensive interest in promoting photogenerated charge separation as well as performances of solar fuel production,but it is still challenging for (oxy)nitride photocatalysts due to their uncontrollable ammonia thermal preparative process.In this work,we report a synthesis on heterostructure of Ta₃N₅nanorods and Ca Ta O₂N (CTON) nanosheets (denoted as Ta₃N...     

Fast Li+ migration in LiPON electrolytes doped by multi-valent Fe ions

Achieving superior ionic conductivity of Li PON solid electrolyte films is critical for the solid-state thinfilm batteries with high energy density. Here we describe a method of preparing Li PON with promising ionic migration capability and high work function by systematically tailoring the concentration of Fe ions doping. Fe-doped LiPON exhibits excellent ionic conductivity(1.08 × 10^-5S cm^-1, nearly 10 times higher than the pristine LiPON), low ionic activation energy, and...     

Scalable preparation and direct visualization of cyclic polymers via self-folding cyclization technique

Cyclic polymers exhibit distinct properties compared with their linear counterparts due to the lack of chain ends.However,the scalable synthesis of cyclic polymers remains a major challenge,especially for ring-closure method.Herein,we report a novel strategy for large-scale preparation of cyclic polymers,which relies on the prior self-folding of anthracene-telechelic amphiphilic random copolymers(poly((oligo(ethylene glycol) acrylate)-co-(dodecyl acrylate)),P(OEGA-co-DDA)) into single-chain poly...     

White-light-driven fluorescence switch for super-resolution imaging guided photodynamic and photoacid therapy

Photocaged fluorophores with photoactivatable characteristics presented important applications in imaging the biological structures and processes.Taking advantage of their super-resolution imaging merits to manipulate and visualize anti-cancer treatment is always a goal of modern clinical medicine.Traditional photodynamic therapy(PDT) is a noninvasive treatment but limited in intracellular oxygen content.Type I PDT and photoacid therapy(PAT) are two effective supplements of traditional PDT espec...     

The structure-performance correlation of bulk-heterojunction organic solar cells with multi-length-scale morphology

We build a general multi-length-scale morphology model with mixing phase and pure phase fibril structure, and simulate corresponding organic solar cells performance. Systematical multi-length-scale morphology optimization process by changing the proportion of mixing phase and pure phase in different period width cases shows a clear correlation between period width and device performance that a smaller period width with appropriate proportion of mixing phase and fibril structure is advantageous t...     

A gauge theory for two-band model of Chern insulators and induced topological defects

In this paper a gauge theory is proposed for the two-band model of Chern insulators.Based on the so-calle't Hooft monopole model,a U(1)Maxwell electromagnetic sub-field is constructed from an SU(2)gauge field,from which arise two types of topological defects,monopoles and e2 merons.We focus on the topological number in the Hall conductance σ_xy=e²/hC,where C is the Chern number.It is discovered that in the monopole case C is indeterminate,while in the meron case C takes different values,due to a varying on-site energy m.As a typical example,we apply this method to the square lattice and compute the winding numbers(topological charges)of the defects;the C-evaluations we obtain reproduce the results of the usual literature.Furthermore,based on the gauge theory we propose a new model to obtain the high Chern numbers|C|=2,4.     

Tunable and highly sensitive temperature sensor based on graphene photonic crystal fiber

Optical fiber temperature sensors have been widely employed in enormous areas ranging from electric power industry, medical treatment, ocean dynamics to aerospace. Recently, graphene optical fiber temperature sensors attract tremendous attention for their merits of simple structure and direct power detecting ability. However, these sensors based on transfer techniques still have limitations in the relatively low sensitivity or distortion of the transmission characteristics, due to the unsuitable Fermi level of graphene and the destruction of fiber structure, respectively. Here, we propose a tunable and highly sensitive temperature sensor based on graphene photonic crystal fiber (Gr-PCF) with the non-destructive integration of graphene into the holes of PCF. This hybrid structure promises the intact fiber structure and transmission mode, which efficiently enhances the temperature detection ability of graphene. From our simulation, we find that the temperature sensitivity can be electrically tuned over four orders of magnitude and achieve up to ～ 3.34×10^-3 dB/(cm·℃) when the graphene Fermi level is ～ 35 meV higher than half the incident photon energy. Additionally, this sensitivity can be further improved by ～ 10 times through optimizing the PCF structure (such as the fiber hole diameter) to enhance the light-matter interaction. Our results provide a new way for the design of the highly sensitive temperature sensors and broaden applications in all-fiber optoelectronic devices.     

Visible-light-promoted radical alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester: Synthesis of oxazolines

An efficient photocatalytic alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester has been developed. The transformation is taken advantage of alkyl radicals to attack allylic amide with the assist of inexpensive rose bengal as photocatalyst to prepare a series of alkyl substituted oxazolines in moderate to excellent yields. High regioselectivity, operational safety, mild conditions and excellent substrate generality give this protocol broad application prospects.     

A hybrid organic-inorganic perovskite with robust SHG switching

Owing to the diversity of structure and potential applications in the field of electrics,sensors,and light-emitting diodes,lead halide perovskites have attracted great attention in recent years.Especially those lead halide perovskites with non-centrosymmetric crystal structures usually exhibit nonlinear optical（NLO） characteristics,which may endow them photoelectricity switching functionality.In this work,a lead-based hybrid organic-inorganic perovskite（HOIP） material,trimethyliodomethylammonium...