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[Display omitted] Broadband surface-enhanced Raman scattering (SERS) substrates can achieve strong SERS enhancement at multiple excitation wavelengths, which is highly desirable in diverse fields. Here, a facile and reliable interfacial layer-by-layer self-assembly technique was proposed to construct broadband and sensitive Au@Ag nanorod (NR) monolayer film over nanosphere (MFON) substrate. The Au@Ag NR MFON substrate with ultra-broad spectrum from visible to near-infrared region was achieved by varying the shape of plasmonic nanoparticles, which exhibits excellent SERS activity at different excitation wavelengths. Besides, the size of Au@Ag NRs and polystyrene spheres, and the layer numbers of Au@Ag NR film were altered to optimize the sensitivity of SERS substrates. Notably, the SERS intensity of the optimally designed Au@Ag NR MFON substrate is 25-fold larger than that of Au@Ag NR monolayer film deposition on the plane Si wafer. Furthermore, the optimal Au@Ag NR MFON substrate presents excellent reproducibility and a much wider quantitative detection range, which enables a wide-linear-range analysis of thiram in grape juice by a portable Raman spectrometer. Therefore, we envision that this study opens a new avenue toward the design of ultra-sensitive and broadband SERS platforms with widespread applications. [ABSTRACT FROM AUTHOR]

Antimony selenide (Sb2Se3) is an emerging photovoltaic material. We demonstrate that PbI2 is an effective p-type dopant for Sb2Se3. The Sb2Se3 film was doped by PbI2 by thermal diffusion. Both the hole concentration and conductivity are dramatically increased by doping. We fabricated the Sb2Se3 solar cell using C60 as an electron transport layer by vacuum thermal evaporation. By PbI2 doping, the open-circuit voltage (Voc) is increased from 0.32 to 0.38 V, and the power conversion efficiency is improved from 2.87% to 4.43%. This work provides an effective p-type dopant for Sb2Se3. [ABSTRACT FROM AUTHOR]

Examines a multipolar model for collisional quantum interference (CQI) on rotational energy transfer. Development of the CQI model in a diatom-diatom system; Reference to the time-dependent perturbation theory and multipolar interaction potential; Interrelation between differential and integral interference angles.

The concave star-shaped Au nanocrystals with ten sharp tips endowed them with 12-fold higher SERS enhancements than Au nanospheres. • Au nanocrystals with sharp tips were prepared using pentatwinned Au NSs as seed. • Au nanocrystals provided a broad spectral range from VIS to NI region. • Monolayers of Au nanocrystals displayed strong shape-dependent SERS activity. • Concave nanostars was 12-fold higher SERS enhancement than Au NSs. In this work, various geometries of Au nanocrystals with sharp tips including decahedra, concave star, and spindle were synthesized through Ag underpotential deposition-dominated growth approach based on utilizing a novel type of Au nanoseed (i.e., pentatwinned Au nanospheres). These as-prepared Au nanocrystals exhibited a broad localized surface plasmon resonance (LSPR) tunability from visible to near-infrared region. Furthermore, we fabricated the monolayer film based on Au nanocrystals with different morphologies through liquid/liquid interface self-assembly technique, which displayed strong shape-dependent surface enhanced Raman scatting (SERS) performance. More significantly, concave star-shaped Au nanocrystals with ten sharp tips endowed them with 12-fold higher SERS enhancements than Au nanospheres, which was in line with the simulation results by finite difference time domain (FDTD) method. Our study provides a novel route for fabrication of Au nanocrystals with diversified structures, and the efficient SERS substrates have great prospect for the applications in ultrasensitive chemical and biological sensing. [ABSTRACT FROM AUTHOR]

An effective and simple method for the fabrication of Ag nanosheets (NSs) was developed via citrate-assisted galvanic replacement at room temperature. The effects of reaction time, concentration of AgNO3 and citrate on the morphology and surface-enhanced Raman scattering (SERS) performance of Ag NSs were investigated systematically. The results indicated that citrate played a vital role on preparing uniform Ag NSs, because it could retard the reaction rate and control the direction of Ag growth. Furthermore, citrate was bound weakly toward Ag NSs and easily replaced by probe molecules, which opened a new avenue for the fabrication of clean SERS substrates. In addition, the Ag NSs substrate exhibited a high sensitivity in SERS detection and the analytical enhancement factor was up to 7.93 × 105 with the minimum detected concentration of R6G as low as 10−8 M. Moreover, the color mapping was relatively uniform and the relative standard deviation was below 15%, revealing that the SERS performance of Ag NSs substrate was highly reproducible. Consequently, we believe this citrate-directed galvanic replacement could regulate the morphology and produce clean and highly active SERS substrates, which would be potentially useful for its practical application. [ABSTRACT FROM AUTHOR]