Ultra-thin Highly Absorbing Medium-based Optical Nanocavity for Photonic and Optoelectronic Devices

Optical cavities, which consist of an optically transparent medium with wavelength-scale thickness, have been widely used in various areas ranging from lasers and sensors to filters. In this talk, I will present our recent accomplishment of angle invariant structural color filters with high-color-purity exploiting the optical cavity featuring strong resonance behaviors in highly absorbing media with the ultra-thin cavity thickness as compared to the wavelength of incident light, which is distinctly different from conventional optical cavity systems. I will also introduce a new multi-functional photovoltaic (PV) scheme integrating novel optical design and electrical design to create colored semitransparent PV cells that can harmoniously incorporate aesthetic functionalities into building envelopes, such as windows, facades, and walls, thus allowing large surfaces of the buildings to be efficiently utilized for light-harvesting. The presented approach could be easily applicable to other wavelength/material systems and thus open door to numerous applications, such as energy-efficient ultra-thin colored display technologies and decorative building-integrated PV.