Research Projects

Phase Change Memory Materials are believed to be the future materials for memory storage, replacing flash memory and other non-volatile Random Access Memories (RAM). Chalcogenide alloys such as Ge2sb2Te5, popularly known as GsT, is one of the important class of material compatible with complementary metal-oxide-semiconductor (CMOs) technology and has the potential to be used as a multilevel memory realize the high density data storage. The state of art research in this area are focusing on neuromorphic computing and look for the Ge-sb-Te system as a suitable candidate for selective ignitions mimicking brain actions. This is an Artificial Intelligence based concept and going to replace the future manpower with logical thinking capacity. A detailed study of phase change phenomena would be desirable to get further expertise in this advanced area of computing. As doped GsT samples prefer to go to the stable hexagonal structure rather than the cubic NaCl structure, which can be understood from the changes in vacancy distribution with increasing As. These vacancies on the Ge/sb sub-lattice are essential for fast crystallization and play a crucial role in amorphous to NaCl phase transitions in GsT. The crystallization dynamics in this alloy is very interesting. Though, As is known to be a toxic material, it is being used heavily in the semiconductor industry for solar cells and high-speed optoelectronic devices. The fast crystallization is happening in a timescale of a few nanoseconds. However the crystallization dynamics in such a short time scale could not be understood completely due to the experimental limitations. I-V switching with different pulse rates and related characterizations would enable us to understand fast crystallization dynamics in such devices. such a study would enable the scientific community to understand the realistic nucleation and growth phenomena behind the ultrafast phase transition.