Band structure engineered Germanium-Tin (GeSn) p-channel tunnel transistors

In this work, we perform a detailed materials and device design evaluation for p-channel homo-junction and hetero-junction Tunnel FETs in Ge and GeSn material system. We start with atomistic level materials simulation using first principles density functional theory (DFT) and extend it to device level TCAD simulation. We show clearly the impact of tuning Sn composition to engineer the band structure and control the relative contribution of the direct and phonon assisted indirect band-to-band tunneling to design and demonstrate p-channel Tunnel FET in the Group IV system that are competitive with their III-V compound semiconductor counterparts.