Mathias Steiner

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Graphene has extraordinary electronic and optical properties and holds great promise for applications in photonics and optoelectronics. Demonstrations including high-speed photodetectors, optical modulators, plasmonic devices, and ultrafast lasers have now been reported. More advanced device concepts would involve photonic elements such as cavities to(More)
The dynamics of excitons in individual semiconducting single-walled carbon nanotubes was studied using time-resolved photoluminescence (PL) spectroscopy. The PL decay from tubes of the same (n,m) type was found to be monoexponential, however, with lifetimes varying between less than 20 and 200 ps from tube to tube. Competition of nonradiative decay of(More)
The high carrier mobility and thermal conductivity of graphene make it a candidate material for future high-speed electronic devices. Although the thermal behaviour of high-speed devices can limit their performance, the thermal properties of graphene devices remain incompletely understood. Here, we show that spatially resolved thermal radiation from biased(More)
We study the origin of a photocurrent generated in doped multilayer black phosphorus (BP) phototransistors, and find that it is dominated by thermally driven thermoelectric and bolometric processes. The experimentally observed photocurrent polarities are consistent with photothermal processes. The photothermoelectric current can be generated up to a(More)
We studied spatially isolated single-walled carbon nanotubes (SWNTs) immobilized in a quasi-planar optical lambda/2-microresonator using confocal microscopy and spectroscopy. The modified photonic mode density within the resonator is used to selectively enhance or inhibit different Raman transitions of SWNTs. Experimental spectra are presented that exhibit(More)
We investigate experimentally and theoretically the fluorescence emitted by molecular ensembles as well as spatially isolated, single molecules of an organic dye immobilized in a quasi-planar optical microresonator at room temperature. The optically excited dipole emitters couple simultaneously to on-and off-axis cavity resonances of the microresonator. The(More)
The authors studied spatially isolated terrylene molecules immobilized in a quasiplanar optical ␭ / 2-microresonator using confocal microscopy and spectroscopy at variable temperatures. At T = 1.8 K, they observed individual molecules relaxing into microresonator-allowed vibronic levels of their electronic ground state by emission of single fluorescence(More)
^ but chose to equate it with a postulated Gaskiers-related d 13 C excursion from circa 580 Ma (35). Instead, our data indicate that this globally correlated negative d 13 C excursion is not related to any known glaciation (36). The duration of this excursion is unconstrained; however, given that it is captured within over 100 m of section in Oman (Fig. 1)(More)
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