Charge density wave activated excitons in TiSe2–MoSe2 heterostructures

Autor: Jaydeep Joshi, Benedikt Scharf, Igor Mazin, Sergiy Krylyuk, Daniel J. Campbell, Johnpierre Paglione, Albert Davydov, Igor Žutić, Patrick M. Vora
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: APL Materials, Vol 10, Iss 1, Pp 011103-011103-10 (2022)
Druh dokumentu: article
ISSN: 2166-532X
DOI: 10.1063/5.0067098
Popis: Layered materials enable the assembly of a new class of heterostructures where lattice-matching is no longer a requirement. Interfaces in these heterostructures therefore become a 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 of temperature-dependent and spatially resolved PL measurements reveal that this peak is unique to the TiSe2–MoSe2 interface, is higher in energy compared to the neutral exciton, and exhibits exciton-like characteristics. The feature disappears at the TiSe2 charge density wave transition, suggesting that the density wave plays an important role in the formation of this new exciton. We present several plausible scenarios regarding the origin of this peak that individually capture some aspects of our observations but cannot fully explain this feature. These results therefore represent a fresh challenge for the theoretical community and provide a fascinating way to engineer excitons through interactions with charge density waves.
Databáze: Directory of Open Access Journals