| 초록 |
Colloidal semiconductor and metal nanocrystals (NCs) have been shown to be promising materials for electronic and optoelectronic device applications because of their unique size-dependent properties and solution processability. However, the integration of these materials into devices has been challenging due to a lack of available method to accurately control their fundamental properties as well as the surface and interface chemistry. Here, we study the physics of charge carriers in NC thin films and engineer the inherent properties of NC thin films thorough surface and interface engineering. First, we develop a novel and systematic methods to engineer the surface chemistry and stoichiometry of metal chalcogenide semiconducting NCs to control the charge carrier statistics. We demonstrate that remote doping and surface passivation are efficient ways to achieve high carrier mobility and lifetime in NC thin films and design high performance NC based field effect transistor, circuits, photodetector, and photovoltaic cells. Second, we engineer the interface of metal NCs to investigate and control the fundamental charge transport mechanism as well as their electrothermal and electromechanical properties. We reveal that selective ligand exchange processes enables to achieve tunable temperature coefficient of resistant and gauge factor of NC thin films, which are standard sensitivity of temperature and strain sensor applications, respectively. Solution based and orthogonal fabrication processes are introduced to integrate the various functional NC thin films to realize multi-functional and multi-array sensors into a single devices. Unconventional materials design and strategy provides a pathway for designing NC based wearable sensors and energy harvesting devices. |
