Core–shell nanotubes to enhance electrical bistability for 2-bit memory

Abstract

We have grown core–shell nanotubes with CNTs in the core and CdS as the shell. The thickness of the shell has been varied by controlling the reaction parameters. In devices based on such core–shell nanotubes, the nanotubes act as carrier-transporting channels to augment charge confinement in the shell. Increasing the density of confined carriers results in enhanced electrical bistability and memory phenomena in CdS. With widely separated low- and high-conducting states, we were able to scale the high-state, so that different high-conducting states could be achieved for multi-level memory applications.