Monolithic light concentration by core-shell TiO2 nanostructures templated by monodisperse polymer colloidal monolayers
by Cherry, R.; Muhanga, J. J.; Mehrabi, H.; Conlin, S. K.; Coridan, R. H.
Nanostructured dielectric overlayers can be used to increase light absorption in nanometer-thin films used for various optoelectronic applications. Here, the self-assembly of a close-packed monolayer of polystyrene nanospheres is used to template a core-shell polystyrene-TiO2 light-concentrating monolithic structure. This is enabled by the growth of TiO2 at temperatures below the polystyrene glass-transition temperature via atomic layer deposition. The result is a monolithic, tailorable nanostructured overlayer fabricated by simple chemical methods. The design of this monolith can be tailored to generate significant absorption increases in thin film light absorbers. Finite-difference, time domain simulations are used to explore the design polystyrene-TiO2 core-shell monoliths that maximize light absorption in a 40 nm GaAs-on-Si substrate as a model for a photoconductive antenna THz emitter. An optimized core-shell monolith structure generated a greater than 60-fold increase of light absorption at a single wavelength in the GaAs layer of the simulated model device.
- Journal
- Nanotechnology
- Volume
- 34
- Issue
- 34
- Year
- 2023
- Start Page
- 10
- URL
- https://dx.doi.org/10.1088/1361-6528/acd787
- ISBN/ISSN
- 1361-6528; 0957-4484
- DOI
- 10.1088/1361-6528/acd787