Bioinspired patterned photonic junctions for plasmon-enhanced metal photoluminescence and fluorescence: design of optical cavities for near-infrared electronics

Abstract

Photonic junctions with their plasmonic components can outstandingly amplify the light-matter interactions, boost the localized surface plasmon resonance and tightly concentrate the optical electromagnetic fields. The mechanisms of plasmon-enhanced metal photoluminescence (PL) and especially fluorescence (FL) emission enhancement of plasmonic junctions (PJs) in optoelectronic devices are still undisclosed in many aspects. Herewith, various bioinspired designs of colonial PJs are investigated, where the geometrical features of Au nanoantennas are originated from diatoms patterns. Developed PJs are based on few nanometer thick heterostructured metal oxide spacer semiconductors sandwiched between Au antennas. PL and dynamic FL spectroscopy measurements are carried out to investigate and understand the underlying effects behind the tangible increase of absorption of IR-lights (70%), outstanding increase of PL emissions (43 times) and dynamic FL characteristics of optical cavities. Considerable high-level PL emission of dot-like PJs is attributed to the development of horizontal Fabry–Pérot cavities and the higher Purcell factors of fabricated photonic structures. The obtained data suggest that two-dimensional (2D) heterostructured metal oxide spacer constructively improves the photonic characteristics of PJs. Tailoring plasmonic dot-like PJs into functional photodetectors resulted in 27.4 A/W photoresponsivity, 44% external quantum efficiency (EQE) and ultra-fast microsecond photo-response at near-infrared (IR) light illumination (∼800 nm). Findings demonstrate the outstanding plasmonic structures’ capability for further development of novel IR optoelectronics.