Fabrications of twisted moiré photonic crystal and random moiré photonic crystal and their potential applications in light extraction

Abstract

Twisted moiré photonic crystal is an optical analog of twisted graphene or twisted transition metal dichalcogenide bilayers. In this paper, we report the fabrication of twisted moiré photonic crystals and randomized moiré photonic crystals and their use in enhanced extraction of light in LEDs. Fractional diffraction orders from randomized moiré photonic crystals are more uniform than those from moiré photonic crystals. Extraction efficiencies of 76.5%, 77.8% and 79.5% into glass substrate are predicted in simulations of LED patterned with twisted moiré photonic crystals, defect-containing photonic crystals and random moiré photonic crystals, respectively, at 584 nm. Extraction efficiencies of optically pumped LEDs with 2D perovskite (BA)2(MA)n–1PbnI3n+1 of n=3 and (5-(2’-pyridyl)-tetrazolato)(3-CF3-5-(2’-pyridyl)pyrazolato) platinum(II) (PtD) have been measured.

Light Confinement in Twisted Single-Layer 2D+ Moiré Photonic Crystals and Bilayer Moiré Photonic Crystals

“…coupling between dual sublattices lead to a disappearance of the first-order diffraction spots of (1, 0), (0, 1), (−1, 0), and (0, −1) as confirmed by the experiments [48]. Here, we generate two types of patterns.…”

“…It is stronger in the central region than at the edge in Figure 1c. The weak coupling between dual sublattices lead to a disappearance of the first-order diffraction spots of (1, 0), (0, 1), (−1, 0), and (0, −1) as confirmed by the experiments [48].…”

“…The data are not publicly available due to limited ac The validation of simulation results is necessary as in recent applications [56]. The simulated E-field propagation along the same set of sublattices in Figure 5a,b,e corresponds to the disappearance of first-order diffraction spots that have recently been observed in experiments [48]. Next, we should work on the fabrication of single-layer 2D+ moiré PhCs in silicon through the double-conversion process described above [57].…”

“…Moiré PhCs can be twisted bilayers [8,18,20,21,23,24,[26][27][28][29][30][31][32][33][34][35][36][37][38] that can be ideally fabricated by E-beam lithography or a twisted single-layer moiré pattern [19,22,[39][40][41][42][43][44][45][46][47][48], which is formed by laser interference in photorefractive crystals, holographic lithography, or E-beam lithography. The single-layer moiré photonic lattice has been generated in a photorefractive crystal by a shallow modulation of the refractive index induced by two mutually twisted laser interferences.…”