title: Proposal for dark exciton based chemical sensors.
abstract: The rapidly increasing use of sensors throughout different research disciplines and the demand for more efficient devices with less power consumption depends critically on the emergence of new sensor materials and novel sensor concepts. Atomically thin transition metal dichalcogenides have a huge potential for sensor development within a wide range of applications. Their optimal surface-to-volume ratio combined with strong light-matter interaction results in a high sensitivity to changes in their surroundings. Here, we present a highly efficient sensing mechanism to detect molecules based on dark excitons in these materials. We show that the presence of molecules with a dipole moment transforms dark states into bright excitons, resulting in an additional pronounced peak in easy accessible optical spectra. This effect exhibits a huge potential for sensor applications, since it offers an unambiguous optical fingerprint for the detection of molecules-in contrast to common sensing schemes relying on small peak shifts and intensity changes.
authors.affiliation: Department of Physics, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.|Institut für Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany.
authors.forename: Maja
authors.initials: M
authors.lastname: Feierabend
authors.affiliation: Department of Physics, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.|Institut für Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Berghäuser
authors.affiliation: Institut für Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Knorr
authors.affiliation: Department of Physics, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
authors.forename: Ermin
authors.initials: E
authors.lastname: Malic