In this article, Ag-encapsulated Au nanorods (Au@Ag NRs) are prepared and introduced into dye-sensitized solar cells (DSSCs). As a unique plasmonic nanostructure, this composite exhibits the superiorities of enhanced light-harvesting as well as restrained charge recombination of DSSCs. Remarkably, the enhanced light absorption of the photoanode can be obtained via the surface plasmon resonance (SPR) effect of the Au@Ag NRs, whereas a broadened absorption in the red and near-infrared (NIR) region ensures the full utilization of the solar energy. Beyond the dominated optical utility, the presence of the Au@Ag NRs promotes the suppression of the charge recombination, further enhancing the photochemical catalysis of DSSCs. An optimized Au@Ag NR modified DSSC is achieved with a power conversion efficiency of 8.43%, which is significantly superior to that of the pure TiO₂ DSSC with a PCE of 5.91%.

Lasing from a planar waveguide with the blend of Polystyrene(PS): Poly-methylmethacrylate(PMMA) doped with tris(8 -hydroxyquinolinato)aluminum(Alq₃) and 4-(dicyanomethylene)-2-tert- butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran(DCJTB) was investigated. Due to phase separation of the blend of PS:PMMA during the solvent evaporation process, a waveguide with granular surface was obtained, which has 2D island-like nanostructures with diameters ranging between 200 and 400 nm and heights at about 25 nm. Pumped by a YAG laser with wavelength of 355nm, a significant random lasing was observed. Compared to the amplified spontaneous radiation (ASE) of planar waveguides with only PMMA or PS doped with Alq3:DCJTB prepared under the same conditions, the lasing threshold of the former is decreased by about 5 times, and the full width at half maximum (FWHM) is reduced to 1.7nm from 12~15 nm. Our experiments show a promising method to achieve lower threshold for organic lasers.

The electric field-modulation of the spontaneous emission (SE) and amplified spontaneous emission (ASE) in organo-lead halide perovskite CH₃NH₃PbI₃ (aliased as MAPbI₃) layer has been investigated. With the increase of the external applied electric field, the electric field-induced quenching of the SE and ASE intensity was observed, accompanying with a blue-shift of the ASE emission peaks, which can be attributed to field-induced ionization of photogenerated excitons in the MAPbI₃ layer. Based on the analysis of quenching factor and the dielectric constant, we estimated an exciton binding energy ∼36 meV at room temperature, which will provide useful insights into the optical-electrical characteristics of MAPbI₃ and pave the way for the future optoelectronic applications.