Nanoscale electrically driven light-emitting sources with tunable wavelength represent a milestone for implementation of integrated optoelectronic chips. Plasmonic nanoantennas exhibiting an enhanced local density of optical states (LDOS) and strong Purcell effect hold promise for fabrication of bright nanoscale light emitters. Here, we justify gold parabola-shaped nanobumps and their ordered arrays produced by direct ablation-free femtosecond laser printing as broadband plasmonic light sources electrically excited by a probe of scanning tunneling microscope (STM). I–V curves of the probe-nanoantenna tunnel junction reveal characteristic bias voltages correlating with visible-range localized (0.55 and 0.85 μm) and near-IR (1.65 and 1.87 μm) collective plasmonic modes of these nanoantennas. These multiband resonances confirmed by optical spectroscopy and full-wave simulations provide enhanced LDOS for efficient electrically driven and bias-tuned light emission. Additionally, our studies confirm remarkable applicability of STM for accurate study of optical modes supported by the plasmonic nanoantennas at nanoscale spatial resolution.

We suggest an approach to mass sensing via tracing the shift of the node position as an alternative to current sensing approaches based on the detection of the frequency shift. We demonstrate the compatibility of our approach with fast and versatile in situ resonator fabrication and mass measurements by means of a scanning electron microscope. The proposed sensing mechanism is minimally affected by parasitic deposition during the measurement. Within this approach, we demonstrate the measurement of several femtogram masses for single-segmented amorphous carbon nanowire cantilevers. We use the experimental results to extract material parameters of the cantilever fabricated inside a microscope chamber. We use these material parameters to model the mass-sensing performance of the double-segmented cantilever geometry. Double-segmented cantilevers show Fano resonances originated from the coupling between top and bottom segment resonances. This coupling leads to two-to three-fold responsivity enhancement in comparison to a single-segment cantilever. Our approaches to mass sensing and sensitivity estimation are general and can be extended to other cantilever materials applied for mass and force measurements.

This work suggests a new approach to weighting the nanoscale objects placed at the tip of cantilever vibrating inside the camera of scanning electron microscope. In contrast to traditional approach to mass determination, we suggest tracing the shift of the node of the second vibration mode as an alternative to frequency shift measurement. We demonstrate the applicability of our approach to carbon nanowhisker cantilevers grown on tungsten needles by focused electron beam induced deposition. We compare experimentally the performance of the suggested approach with the traditional frequency shift-based method.