Blinking and spectral diffusion are hallmarks of nanoscale light emitters and a challenge for creating stable fluorescent biomarkers or efficient nonclassical light sources. Here, we demonstrate suppression of blinking and spectral diffusion of individual single-wall carbon nanotubes by manipulation of their dielectric environment, resulting in 5-fold enhanced light emission. In addition, it was found that the characteristic slopes of the blinking power laws are largely independent of the dielectric environment in the limit of a large number of switching events. In contrast, the on/off ratio determined from statistical occurrence analysis is found to be improved by 3 orders of magnitude toward the on state, making the on/off ratio an important measure for charge transfer from/into the local dielectric environment of a quantum emitter. Furthermore, our approach is compatible with integration into cavities, in contrast to previous demonstrations of spectral diffusion suppression achieved in free-standing single-wall carbon nanotubes. This opens up possibilities to couple the exciton emission of nonblinking carbon nanotubes to cavity modes to further benefit by the Purcell effect and to enhance the light extraction efficiency, in order to ultimately demonstrate efficient photonic devices.

We fabricated dye sensitized graphene antidot superlattices with the purpose of elucidating the role of the localized edge state density. The fluorescence from deposited dye molecules was found to strongly quench as a function of increasing antidot filling fraction, whereas it was enhanced in unpatterned but electrically backgated samples. This contrasting behavior is strongly indicative of a built-in lateral electric field that accounts for fluorescence quenching as well as p-type doping. These findings are of great interest for light-harvesting applications that require field separation of electron-hole pairs.

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We observe conductivity oscillations with aperiodic spacing to only one side of the tunneling current in a dual-gated graphene field effect transistor with an n-p-n type potential barrier. The spacing and width of these oscillatoins were found to be inconsistent with pure Farbry-Perot-type interferences, but are in quantitative agreement with theoretical predictions that attribute them to resonant tunneling through quasi-bound impurity states. This observation may be understood as another signature of Klein tunneling in graphene heterojunctions and is of importance for future development and modeling of graphene based nanoelectronic devices.

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