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Resonant Raman scattering is highly desired for material study. It is experimentally not easy to reach the resonant scattering interaction between an incident photon and a material due to the limited available laser wavelengths. In this study, by employing silver plasmonic nanoparticles deposited on glass substrate and by in situ adjusting the cadmium sulfide (CdS) band gap through heat treatment, resonant Raman scattering condition (laser wavelength of 514.5 nm) was fully achieved in nanocrystalline CdS thin films. The dramatically enhanced Raman scattering allowed us to in situ monitor the phase transition that occurred during the heat treatment and to quantitatively characterize the fraction of the zincblende (cubic) CdS in the main base of wurtzite (hexagonal) CdS. Raman multi-phonon and the corresponding high-order scattering modes were observed due to the much enhanced surface nanoplasmonic electric field. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Surface plasmon (SP) enhancement of photoluminescence (PL) from a green-emitting InGaN/GaN quantum well (QW) using nanoparticles (NPs) made of different metals and their combinations was investigated. The NPs were formed by annealing the metal films in N2 followed by rapid cooling. Four-fold enhancement in PL intensity was achieved using random metal NPs made of Cu on Mg (Cu-Mg) double metal film that was more than two folds of the enhancement observed by AgNPs. Reversing the order of metal film deposition (Mg on Cu) resulted in much lower PL intensity due to significantly different NPs size distribution as the given annealing conditions did not cause homogeneous alloying of the two metals. The results pave the way for the application of NPs of relatively low-cost unconventional metals and their combinations in the SP enhancement of LEDs. [ABSTRACT FROM AUTHOR]

Surface plasmon (SP)-enhanced quantum-well (QW) LEDs have proved their potential in replacing conventional lighting devices for their high-performance capabilities in ultraviolet (UV), blue and green spectral ranges. The SP-enhanced QW-LEDs have applications in light emission enhancement, light polarization, color conversion, and speed modulation. The electric field of the plasmonic mode of a metal couples with the exciton energy of QWs in resonance results in efficiency enhancement to several folds. The strength of the SP–QW coupling is mainly influenced by the type of metal used for SP enhancement, the metal nanostructure geometry, and the penetration depth of the SP fringing field in the p-GaN. The use of an appropriate dielectric interlayer between the metal and the p-GaN allows further control over SP resonance with QW emission wavelength. The penetration depth defines the p-GaN thickness and the QW period number for effective SP–QW coupling. The optimization of these parameters is key to achieve high efficiencies in SP-enhanced QW-LEDs for various applications. This review explains the SP enhancement mechanism and the key challenges facing the SP enhancement of QW-LEDs. The main factors that affect the SP–QW coupling have been explained in detail based on recent reports devoted to this field. [ABSTRACT FROM AUTHOR]