Fig. 1. (a) Sketch of the experimental setup (see text for details). (b) Fluorescence image of single dibenzoterrylene (DBT) molecules embedded in an anthracene (AC) microcrystal obtained through confocal scanning; (c) photoluminescence (PL) time trace and (d) normalized second-order photon correlation function of fluorescence from a DBT molecule. The inset in (d) is the emission spectrum of the same molecule. (e) Atomic force microscope (AFM) topographic image of a part of an AC microcrystal. (f) Left: schematic illustration of the sublimation process of the AC microcrystal; right: cross-sectional plots of the height along the same blue dashed line shown in (e) at different times, which demonstrate the sublimation process.

Fig. 2. (a) Schematic diagram of the sample structure. (b) Measured and simulated back-focal plane (BFP) images of the emission from a single molecule oriented along the b axis of the AC microcrystal. (c)–(f) Measured and fitted PL decay curves from the same DBT molecule at different times. Insets: AFM topographic images of the region of the AC microcrystal where the molecule is located. The red star marks the location of the measured molecule. Scale bar: 500 nm.

Fig. 3. (a) Measured and fitted total decay rates (1/τ) of two different DBT molecules as functions of the AC microcrystal thicknesses. (b) Purcell factor distribution versus emitter dipole position h and the microcrystal thickness H.