Efficient active waveguiding properties of Mo₆nano-cluster-doped polymer nanotubes

Abstract

We investigate 1D nanostructures based on a Mo6@SU8 hybrid nanocomposite in which photoluminescent Mo6 clusters are embedded in the photosensitive SU8 resist. Tens of micrometers long Mo6@SU8-based tubular nanostructures were fabricated by the wetting template method, enabling the control of the inner and outer diameter to about 190 nm and 240 nm respectively, as supported by structural and optical characterizations. The image plane optical study of these nanotubes under optical pumping highlights the efficient waveguiding phenomenon of the red luminescence emitted by the clusters. Moreover, the wave vector distribution in the Fourier plane determined by leakage radiation microscopy gives additional features of the emission and waveguiding. First, the anisotropic red luminescence of the whole system can be attributed to the guided mode along the nanotube. Then, a low-loss propagation behavior is evidenced in the Mo6@SU8-based nanotubes. This result contrasts with the weaker waveguiding signature in the case of UV210-based nanotubes embedding PFO (poly(9,9-di-n-octylfluorenyl-2,7-diyl)). It is attributed to the strong reabsorption phenomenon, owing to overlapping between absorption and emission bands in the semi-conducting conjugated polymer PFO. These results make this Mo6@SU8 original class of nanocomposite a promising candidate as nanosources for submicronic photonic integration.

Supramolecular Anchoring of Octahedral Molybdenum Clusters onto Graphene and Their Synergies in Photocatalytic Water Reduction

“…Their specificity, compared to coordination complexes, is the delocalization of electrons involved in the metal–metal bonds on the whole metallic architecture. Because those are not confined on one metal center, transition-metal clusters display intermediate behavior between atoms and bulk metals and, in particular, show unique magnetic, optical, or catalytic properties. − Yet, octahedral transition-metal cluster compounds based on a molybdenum, tungsten, or rhenium scaffold (Scheme a) are particularly attractive in the design of functional hybrid nanomaterials with potential applications in optoelectronic, − lighting, theranostic, − or photocatalysis ,,, applications. Because molybdenum or tungsten elements are cheap and abundant, cluster-based compounds constitute promising alternatives to costly iridium­(III)-, platinum­(II)-, or rare-earth-containing luminophores or nonenvironmentally friendly lead hybrid perovskites or cadmium-containing quantum dots.…”

Ionic columnar clustomesogens: associations between anionic hexanuclear rhenium clusters and liquid crystalline triphenylene tethered imidazoliums

“…Complexes with 24 cluster valence electrons can be highly phosphorescent in the red-NIR area. [29][30][31][32][33][34][35] Because of their high potential in biology for ROS production, as nanoscintillators or contrast agents, [36][37][38] in optoelectronic [39][40][41] or lighting, 42 many efforts have been devoted these last years to counterpart their ceramic-like behaviour and integrate them in host matrices. [43][44][45][46][47][48][49][50][51][52][53][54] Hence, several strategies have been developed to solubilize the [M 6 Q i 8 X a 6 ] nanionic units in organic media, 55,56 or to integrate them directly in a polymeric or liquid crystalline organic host matrix 23,25,49,57,58 by replacing, via a metathesis reaction, their alkali counter cations by functional organic ones.…”

Self-ordering promoted by the nanoconfinement of poly(3-hexylthiophene) and its nanocomposite with single-walled carbon nanotubes

“…A second mechanism is the viscosity of the polymer, directly related to the annealing temperature. It has been previously shown that a polymer in liquid phase with a high viscosity promotes the formation of nanowires, while a low viscosity promotes the formation of nanotubes [35][36][37]. In our work, a temperature of 250 °C was a good compromise to get the P3HT in the liquid phase but also to avoid the thermal degradation of P3HT which occurs at higher temperatures.…”