- Tytuł:
- Photoluminescence Studies of Excitonic Complexes in Atomically Thin $Mo(S_y Se_{1-y})_2 $ Alloys
- Autorzy:
- Jadczak, J.
- Powiązania:
- https://bibliotekanauki.pl/articles/1398343.pdf
- Data publikacji:
- 2017-08
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
Transition metal dichalcogenides monolayers
exciton
trion
phonon - Opis:
- Transition metal dichalcogenides show new emergent properties at monolayer thickness, notably strong Coulomb and electron-phonon interactions enable new insight into physics of many body effects. Here, we report photoluminescence and reflectivity contrast measurements of excitons (X) and trions (T) and the Raman spectra of phonons in monolayers of $Mo(S_ySe_{1-y})_2$ alloys with sulfur mole content from y=0 up to y=1. Binary MoSe₂ and ternary $Mo(S_ySe_{2-y})$ alloys exhibit contrasting behavior in the temperature evolution of excitons and trions photoluminescence intensity from T=7-295 K. In MoSe₂ a trion dominates photoluminescence spectra at low temperatures but exciton dominates photoluminescence at higher temperature. In contrast, in ternary $Mo(S_ySe_{1-y})_2$ alloys and MoS₂ trions dominate photoluminescence spectra at all measured temperatures, with the trion to exciton photoluminescence intensity ratio increasing with sulfur content. We attribute the strong increase of the trion photoluminescence intensity in $Mo(S_ySe_{1-y})_2$ monolayers with increase of sulfur mole content to the significant increase of the two-dimensional electron gas concentration and also to the strong exciton-trion coupling mediated by an optical phonon. We also demonstrate that increasing sulfur content in $Mo(S_ySe_{1-y})_2$ alloys stabilizes total photoluminescence intensity at high temperature.
- Źródło:
-
Acta Physica Polonica A; 2017, 132, 2; 307-312
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł