Monolithic high refractive index photonic devices
View Patent ↗Fabricating a high refractive index photonic device includes disposing a polymerizable composition on a first surface of a first substrate and contacting the polymerizable composition with a first surface of a second substrate, thereby spreading the polymerizable composition on the first surface of the first substrate. The polymerizable composition is cured to yield a polymeric structure having a first surface in contact with the first surface of the first substrate, a second surface opposite the first surface of the polymeric structure and in contact with the first surface of the second substrate, and a selected residual layer thickness between the first surface of the polymeric structure and the second surface of the polymeric structure in the range of 10 μm to 1 cm. The polymeric structure is separated from the first substrate and the second substrate to yield a monolithic photonic device having a refractive index of at least 1.6.
1. A method of fabricating a high refractive index photonic device, the method comprising:
heating a first substrate to at least 100° C.;
disposing a polymerizable composition on a first surface of the first substrate after heating the first substrate to at least 100° C.;
contacting the polymerizable composition with a first surface of a second substrate, thereby spreading the polymerizable composition on the first surface of the first substrate;
curing the polymerizable composition to yield a polymeric structure having a first surface in contact with the first surface of the first substrate, a second surface opposite the first surface of the polymeric structure and in contact with the first surface of the second substrate, and a selected residual layer thickness between the first surface of the polymeric structure and the second surface of the polymeric structure in a range of 10 μm to 1 cm; and
separating the polymeric structure from the first substrate and the second substrate to yield a monolithic photonic device,
wherein the refractive index of the monolithic photonic device is at least 1.6, and
further comprising heating the second substrate to a temperature that exceeds the temperature of the first substrate by 25° C. to 50° C. at the time the polymerizable composition is disposed on the first surface of the first substrate.
2. The method of claim 1 , further comprising coating the first surface of the first substrate with a release layer before disposing the polymerizable composition on the first surface of the first substrate.
3. The method of claim 1 , wherein curing the polymerizable composition comprises heating the polymerizable composition to a temperature less than 100° C.
4. The method of claim 1 , wherein the selected residual layer thickness between the first surface of the polymeric structure and the second surface of the polymeric structure is in a range of 250 μm to 500 μm.
5. The method of claim 1 , wherein a transmittance of the monolithic photonic device is greater than 80% between 400 nm and 800 nm.
6. The method of claim 1 , further comprising coating the first surface of the second substrate with a release layer before contacting the polymerizable composition with the first surface of the second substrate.
7. The method of claim 1 , further comprising heating the second substrate to at least 100° C. before contacting the polymerizable composition with the first surface of the second substrate.
8. The method of claim 1 , further comprising partially polymerizing the polymerizable composition before disposing the polymerizable composition on the first surface of the first substrate.
9. The method of claim 1 , wherein the polymerizable composition comprises:
first monomers, each first monomer having at least two vinyl, allyl, or acrylate moieties; and
second monomers, each second monomer having at least two thiol moieties.
10. The method of claim 9 , wherein the polymerizable composition comprises a photoinitiator, a thermal initiator, or both.
11. The method of claim 9 , wherein the polymerizable composition comprises a metal oxide.
12. The method of claim 11 , wherein the metal oxide comprises at least one of titanium oxide, zirconium oxide, and zinc oxide.
13. The method of claim 9 , wherein the polymerizable composition comprises a surfactant.
14. The method of claim 1 , wherein the monolithic photonic device is optically transparent.
15. The method of claim 1 , wherein the polymerizable composition comprises:
20 wt % to 90 wt % of a high viscosity multifunctional component;
5 wt % to 40 wt % of a low viscosity mono- or multifunctional component;
0.2 wt % to 5 wt % of a photoinitiator;
0.2 wt % to 2 wt % of a light stabilizer; and
0.2 wt % to 2 wt % of an antioxidant,
wherein curing the polymerizable composition comprises polymer crosslinking through a single functionality.
16. The method of claim 15 , wherein the polymerizable composition comprises inorganic nanoparticles or molecular level clusters.
17. The method of claim 1 , wherein the polymerizable composition comprises:
20 wt % to 80 wt % of a multifunctional component with a first reactive moiety;
20 wt % to 80 wt % of a multifunctional component with a second reactive moiety;
0.2 wt % to 5 wt % of a photoinitiator;
0.2 wt % to 2 wt % of a light stabilizer; and
0.2 wt % to 2 wt % of an antioxidant,
wherein the first reactive moiety and the second reactive moiety are different, and curing the polymerizable composition comprises polymer crosslinking through cross-reaction through at least the first reactive moiety and the second reactive moiety.
18. The method of claim 17 , wherein the polymerizable composition comprises inorganic nanoparticles having a maximum particle size of 20 nm.
19. The method of claim 1 , wherein the monolithic photonic device is a lens.