| Nanophotonic devices based on solid state materials are traditionally achieved through complex solid-state nano-/micro-fabrication methods. In recent years, the rapid advancement of synthesis of nanometric materials in colloidal forms has provided another wealth of materials with unique optoelectronic properties and solution-based fabrication capability. In this dissertation, I develop several types of nanophotonic devices that utilize colloidal semiconductor nanoparticles (i.e. quantum dots) and/or metal nanoparticles (i.e. plasmonic nanoparticles) as building blocks and are processed completely from solution. The demonstrated work includes (1) nanoscale waveguides based on quantum dots which allow optical signal transfer at a well-defined wavelength in flexible routing geometry with reduced loss mechanism and low cross-talk, (2) quantum dot photodetectors integrated with plasmonic nanoparticles which show wavelength dependent responsivity enhancement of up to 3.3 fold, and (3) sensor array based on nanometric gap quantum dot photodetector exhibiting low cross-talk even at sub-wavelength pitch suggesting great potential to significantly improve resolution compared with state of art CMOS imagers. |
