Observation of Room-Temperature Dark Exciton Emission in Nanopatch-Decorated Monolayer WSe2 on Metal Substrate

Mahfujur Rahaman, Oleksandr Selyshchev, Yang Pan, Rico Schwartz, Ilya Milekhin, Apoorva Sharma, Georgeta Salvan, Sibylle Gemming, Tobias Korn, Dietrich R.T. Zahn

Результат исследования: Научные публикации в периодических изданияхстатьярецензирование


The presence of strong spin–orbit coupling in the valence band and weak spin-splitting in the conduction band result in the lowest energy exciton in WX2 (X = S, Se) being spin forbidden and optically dark. Because of their long lifetimes, dark excitons are highly attractive for quantum optics and optoelectronic applications. To date, studying dark excitonic emissions is limited to cryogenic temperatures or requires very complex experimental configurations to observe them at room temperature (RT). Here, the radiative decay of dark exciton related emission in WSe2 monolayers is studied using both conventional and tip-enhanced photoluminescence (TEPL) at RT. Monolayer WSe2 flakes are sandwiched between noble metal substrates and polydimethylsiloxane nanopatches providing a strong local electrostatic out-of-plane dipole moment with respect to the 2D plane resulting in the observation of dark excitonic emission at RT. The spatial distribution of this dark exciton related emission is studied by TEPL with a spatial resolution of
Язык оригиналарусский
ЖурналAdvanced Optical Materials
Номер выпуска24
СостояниеОпубликовано - 1 дек. 2021

Ключевые слова

  • WSe 2
  • dark and bright excitons
  • photoluminescence
  • transition metal dichalcogenides
  • valley physics