Biomimetic Nanostructure Fabrication to Increase Light Transmission Efficiency in Optoelectronic Devices

We report on enhancing the coupling between an light emitting diode and photodiode pair by fabricating biomimetic sub-wavelength nanostructures on both of the optoelectronic devices. This modification helps to increase the light transmission of each device, which enhances the coupling between the device pairs. The process involves the formation of a self-assembled colloidal crystal of polystyrene nanospheres deposited on a silicon substrate to serve as a mask in reactiveion-etching. The resulting etched nanopattern is transferred from the silicon with polydimethylsiloxane (PDMS) nanoimprint lithography to the surface of an optoelectronic device. The PDMS functions as a mold that imprints the nanostructure pattern on optical adhesive placed on the surface of the device. We demonstrate an increase in photodiode output in optical device pairs consisting of inorganic light emitting diodes and photodiodes with the presence of the biomimetic nanostructures on their surface. The presented results are promising for sensing system applications using pairs of light emitters and detectors.