We demonstrate selectively enhanced emission by controlling the intrachain and interchain excitons of a conjugated polymer through adjusting surface plasmons. Enhanced light emission from the intrachain excitons was observed by coupling the localized surface plasmon resonance with the intrachain band of the conjugated polymer using Ag nanoparticles. Light emission from the interchain excitons was enhanced by exploiting both the increased strength of the interchain dipole due to the image dipole and the coupling between excitons and surface plasmon polaritons (SPPs). As the Ag nanostructures become complete films, light emission from the interchain excitons increased.

A novel blue-emitting LaOCl:Eu²⁺ phosphor has been successfully synthesized using the solid-state reaction. In addition, Ce³⁺ and Tb³⁺ activated LaOCl phosphors have been prepared and compared with the LaOCl:Eu²⁺ phosphor. FE-SEM images clearly indicate that the LaOCl:Eu²⁺ phosphor has a lamellar structure. XRD results and PL measurements for the LaOCl:Eu²⁺ phosphor indicate a preferred orientation along the [001] direction, which results in the blue-emission associated with the spectral characteristics of Eu²⁺. In contrast, the red-emission due to the formation of Eu³⁺ appears in a non-oriented one. These results reveal that Eu²⁺ ions are exclusively stabilized into the (00l) oriented LaOCl crystal lattice because the excitation and emission spectra of the blue-emitting LaOCl:Eu²⁺ phosphor consist of the spectral characteristics of Eu²⁺. The CIE chromaticity index (x = 0.151, y = 0.048) with high color saturation indicates that it is a promising candidate as a blue-emitting phosphor for white-light UV-LEDs.

Although Raman spectroscopy is a major analytical tool in modern chemical experiments, commercial Raman spectrometers remain very pricey for educational and research purposes in individual university laboratories. Thus, this study focused on the structural similarity between the Raman spectrometer and an optical pickup unit (OPU), which is an inexpensive compact optical device used for a part of optical discs. The study investigated whether or not a full set of Raman spectrometer can be developed at a cost of less than 1,000 US$. The OPU-based Raman spectrometer was fabricated using 3D printer-made components, a Raman edge filter, and a laser diode with a wavelength of 520 nm as the light source. A function generator was used as a pulsed power source to analyze the characteristics of the OPU Raman spectrometer according to various frequencies and duty ratios. When using a pulsed DC power supply, the laser wavelength tended to move to a longer wavelength with increases in duty ratios. That is, the higher the frequency at the same duty ratio, the weaker the background light intensity compared with the scattered Raman signal intensity. The findings illustrate that Raman signal strength can be adjusted by adjusting the focal length of the objective lens of the OPU through an external adjustment of an additional DC power. In the Raman spectra of all solid and liquid samples used, the maximum error rate reached approximately 11 cm⁻¹, whereas the maximum intensity deviation reached approximately ± 6%. The cost of the complete OPU Raman spectrometer is less than 1,100 US$ using a function generator as power source and less than 930 US$ using a DC adapter. If the optical density (OD) 6 filter can be replaced with the OD 4 filter, then the costs are expected to decrease to approximately 730 US$.