RESUMO
We propose stretchable plasmonic templates of Au and Au/SiO2 nanoparticles (NPs) to improve the luminescence of CsPbBr3 perovskite nanocrystals (PNCs). These templates are highly flexible and consist of polymer-metal NP composites that facilitate the luminescence enhancement by localized surface plasmons (LSPs) due to coupling with metal NP. This template also prevents the degradation of carrier transport properties for perovskite light-emitting diodes by embedding metal NPs in polymer. The luminescence of PNC film on the template with Au NPs decreases by 21% compared to PNC films on the reference (polymer film without metal NPs), while it increases by 54% for the templates with Au/SiO2 NPs. The observed effects are explained by the luminescence enhancement due to coupling to LSPs formed by the Au/SiO2 NPs and by the prevalence of electron tunneling and dumping for Au NPs.
RESUMO
Free-standing GaN light-emitting diode (LED) structure with high crystalline quality was fabricated by combining electrochemical and photoelectrochemical etching followed by regrowth of LED structure and subsequent mechanical detachment from a substrate. The structural quality and composition of the regrown LED film thus produced was similar to standard LED, but the photoluminescence and electroluminescence intensity of the LED structures on the etched template were several times higher than for standard LED. The performance enhancement was attributable to additional light scattering and improved crystalline quality as a result of the combined etching scheme.