Etch‐Less Nanostructures for Photoluminescence Modification From Plasma‐Enhanced Chemical Vapor Deposition‐Grown Silicon Nanocrystals

Guided mode resonances (GMRs) and (quasi) bound states in the continuum (QBICs) are formed in a waveguide covered by thin 1D or 2D photoresist gratings. To investigate the coupling of these modes to embedded light emitters experimentally, such resist nanostructures were fabricated on waveguides containing silicon nanocrystals embedded in an oxide matrix applying large area laser interference lithography (LIL). We measured the impact of GMRs and symmetry protected QBICs supported by simple photoresist gratings on photoluminescence of silicon nanocrystals and its directionality using angle‐resolved photoluminescence (ARPL) measurements, allowing us to map the dispersion of the photonic modes. Sharp emission peaks with experimentally limited quality factors up to 600 were observed. The possibility to create symmetry protected QBICs without the use of plasma etching reduces the occurrence of nonradiative recombination due to surface defects, simplifies overall fabrication, and extends the range of emitters and waveguide materials, which could be employed. The proposed structures could find applications in biological nanosensors at near infrared as well as optical frequencies.