Polytypic Phase Transitions in Metal and Semiconductor Intercalated Bi2Se3

A clever route to achieve a 2D metal-semiconductor heterostructure or 2D semiconductor heterostructure is through intercalation of zero-valent atomic species. With intercalation of zero-valent elements, fundamentally new physical behaviors arise such as charge density waves or tunable phase transitions. In this talk, the pressure, temperature and concentration dependent phase diagrams of zero-valent metal and semiconductor intercalated bismuth selenide are investigated. Polytypic phase transitions associated with superlattice formation along with order-disorder phase transitions are demonstrated. Hexagonal and striped domain formation consistent with two-dimensional ordering of the intercalant and Pokrovksy-Talapov theory is identified as a function of concentration. These studies provide a complete picture of the structural behavior of zero-valent metal and semiconductor- intercalated Bi2Se3.