Matrix‐induced Linear Stark Effect of Single Dibenzoterrylene Molecules in 2, 3‐Dibromonaphthalene Crystal. Issue 1 (28th November 2018)

• Record Type: Journal Article
• Authors: Moradi, Amin; Ristanović, Zoran; Orrit, Michel; Deperasińska, Irena; Kozankiewicz, Bolesław
• Is Part Of: Chemphyschem. Volume 20:Issue 1(2019)
• Page Start: 55
• Page End: 61
• Publication Date: 2018-11-28
• Subjects: single-molecule spectroscopy -- linear Stark effect -- induced dipole moment -- insertion sites -- density functional calculations; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201800937
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: Absorption and fluorescence from single molecules can be tuned by applying an external electric field – a phenomenon known as the Stark effect. A linear Stark effect is associated to a lack of centrosymmetry of the guest in the host matrix. Centrosymmetric guests can display a linear Stark effect in disordered matrices, but the response of individual guest molecules is often relatively weak and non‐uniform, with a broad distribution of the Stark coefficients. Here we introduce a novel single‐molecule host‐guest system, dibenzoterrylene (DBT) in 2, 3‐dibromonaphthalene (DBN) crystal. Fluorescent DBT molecules show excellent spectral stability with a large linear Stark effect, of the order of 1.5 GHz/kVcm −1, corresponding to an electric dipole moment change of around 2 D. Remarkably, when the electric field is aligned with the a crystal axis, nearly all DBT molecules show either positive or negative Stark shifts with similar absolute values. These results are consistent with quantum chemistry calculations. Those indicate that DBT substitutes three DBN molecules along the a ‐axis, giving rise to eight equivalent embedding sites, related by the three glide planes of the orthorhombic crystal. The static dipole moment of DBT molecules is created by host‐induced breaking of the inversion symmetry. This new host–guest system is promising for applications that require a high sensitivity of fluorescent emitters to electric fields, for example to probe weak electric fields. Abstract : Electrical tuning of single molecules : Tuning narrow optical resonances of single‐molecule quantum emitters requires fluorescent molecules responsive to external electric fields. Dibenzoterrylene (DBT) in 2, 3‐dibromonaphthalene is introduced as a new host‐guest system for single‐molecule spectroscopy. All fluorescent DBT emitters in this molecular crystal show a large and linear Stark effect due to the matrix‐induced breaking of the guest inversion symmetry.