Enhanced Luminescence of Silicon Vacancies in 4H-SiC Nanopillar Arrays

What is it about?

Point defects in silicon carbide (SiC) can act as sources of single photons, which is needed for most quantum applications. We have shown that we can generate silicon vacancies in 4H-SiC by ion implantation. These defects emit light in the near-infrared (~900nm) and we use cathodoluminescence at low temperature (~80K) to study their luminescence. Because most of the emitted light stays trapped inside bulk SiC due to its high refractive index, we etched the material into ordered nanopillar arrays. These nanostructures allow us to enhance the luminescence of the silicon vacancies by up to a factor of four. This demonstrate that we can exalt the brightness from color centers in SiC, without the need for complex optical cavities or resonators.

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Photo by Mitchell Y on Unsplash

Photo by Mitchell Y on Unsplash

Why is it important?

Quantum technologies rely on efficient light sources that can generate and manipulate single photons. Ion implantation allows us to create stable point defects in silicon carbide (SiC), while precisely controlling both their concentration and depth - an essential requirement for scalable quantum devices. However, without efficient light extraction, the integration of these defects into practical devices stays limited. Our results show that fabricating simple nanostructures such as nanopillar arrays can enhance the luminescence of SiC color centers by up to a factor of four. This straightforward and CMOS-compatible way to improve light collection from single photon emitters could represent an important step toward the large-scale production of SiC-based photonic devices.