Shape-controlled synthesis of silver nanocrystals by X-ray irradiation for inkjet printing.

A suite of silver (Ag) nanocrystals have been synthesized using a rapid water radiolysis approach via X-ray irradiation. Various shapes including spheroidal, prism, rod, and multifaceted nanoparticles can be produced by varying the initial concentration of polyvinylpyrrolidone (PVP) relative to silver nitrate (AgNO3). UV-visible spectroscopy and transmission electron microscopy (TEM) coupled with selected area electron diffraction (SAED) have been used to characterize these Ag products. At an optimized reagent ratio, a mixture of high-aspect-ratio rods (tunable to ∼50) and spheroidal particles result. Such a mixture is proven to have highly beneficial melting point and dispersive properties suited to inkjet printing of conductive Ag lines. The resistivity of the printed lines decreases to 77.7 µΩ and 33.1 µΩ after heating to 200 and 350 °C.