Charge density wave activated excitons in TiSe2–MoSe2 heterostructures

• DOI: 10.1063/5.0067098
• Publication Date: 2022-01-05T14:43:35Z
• Authors: Jaydeep Joshi; Benedikt Scharf; Igor Mazin; Sergiy Krylyuk; Daniel J. Campbell; Johnpierre Paglione; Albert Davydov; Igor Žutić; Patrick M. Vora
• Keywords: Charge Density Wave; Charge density; Lattice (music)

Layered materials enable the assembly of a new class heterostructures where lattice-matching is no longer requirement. Interfaces in these therefore become fertile ground for unexplored physics as dissimilar phenomena can be coupled via proximity effects. In this article, we identify an unexpected photoluminescence (PL) peak when MoSe2 interacts with TiSe2. A series temperature-dependent and spatially resolved PL measurements reveal that unique to TiSe2–MoSe2 interface, higher energy compared neutral exciton, exhibits exciton-like characteristics. The feature disappears at TiSe2 charge density wave transition, suggesting plays important role formation exciton. We present several plausible scenarios regarding origin individually capture some aspects our observations but cannot fully explain feature. These results represent fresh challenge theoretical community provide fascinating way engineer excitons through interactions waves.