Enhancement of spontaneous emission in three-dimensional low refractive-index photonic crystals with designed defects

In this work, we demonstrate that low refractive-index three-dimensional photonics crystals with a planar defect, fabricated with the direct laser writing method, can be used to effectively enhance the spontaneous emission (SE) of semiconductor quantum dots (QDs). To achieve this, we develop a controllable and reliable method to integrate quantum dots into the defect-embedded photonic crystals (PCs). Although the overlapping of different direction stop gaps in low refractive-index defect-free three-dimensional photonic crystals imposes a challenge to realize spontaneous emission enhancement at the band edge wavelength, we achieve a 15% enhancement of the spontaneous emission by introducing a tailored planar defect.