Sub-2 nm platinum nanoparticles growth study and device applications

APPLICATIONS Balavinayagam Ramalingam Dr. Shubhra Gangopadhyay, Dissertation Supervisor ABSTRACT This work describes a tilted-target RF magnetron sputter deposition system to grow nanoparticles in a controlled way. With detailed characterization of ultra-high density (up to 1.1 × 1013 cm−2) and ultra-small size Pt nanoparticles (0.5-2 nm), it explains their growth and crystalline properties on amorphous Al2O3 thin films. It is shown that Pt nanoparticle size and number density can be precisely engineered by varying selected experimental parameters such as target angle, sputtering power, substrate-surface-energy and time of deposition to control the energy of the metal atoms in the deposition flux. Based on rate equation modelling of nanoparticle growth, three distinct growth regimes, namely nucleation dependent, coalescence dependent and agglomeration dependent regimes, were observed. With this control over the growth regime, a myriad of nanoparticle configurations were observed for size dependent applications.