The key components of photonic integrated circuits are nanoscale optica emitters and nanowaveguides. III-V semiconductor nanostructures are considered as the most promising material platform for these components due to highly efficient luminescence and high refractive index, but the problem of emission coupling with waveguide is to be solved. In this work, the use of GaP nanowires (NWs) with different types of doping (GaP:Si or GaP:Be) is proposed as optical waveguides with directly integrated electrically-driven light sources, solving the problem of emission-to-waveguide coupling. Single NWs are integrated with electrodes and pump electroluminescence by a tunnel junction allowing to study emission properties with nanoscale spatial resolution. Basing on the experiments on scanning tunnelling microscopy (STM), electron microscopy, time-resolved photoluminescence micro-spectroscopy, X-ray diffraction, and STM-induced electroluminescence, it is proven that GaP NWs exhibit different integrated light-source on doping type of NWs. GaP:Be NWs contain inclusion of the crystalline wurtzite phase with a direct bandgap, and, thus, these NW regions can be considered as electrically-driven nanoscale sources of light monolithically integrated into GaP NW-based waveguides. Meanwhile, GaP:Si NWs work as optical waveguides capable of efficient light generation over the entire length of NW. The developed designs are promising for construction of integrated photonic circuits. GaP nanowires (NWs) with different types of doping (GaP:Si or GaP:Be) are empolyed as optical waveguides with integrated electrically-driven light sources, solving the problem of emission-to-waveguide coupling. GaP:Be NWs contain inclusions of the crystalline wurtzite phase with a direct bandgap, and, thus, these NW regions can be considered as electrically-driven nanoscale light sources monolithically integrated into GaP NW-based waveguides. image

The paper reports on experiments on the observation of scanning tunnel mi-croscope (STM)-induced light emission (STM-LE) from bare silicon surfaces and modified with STM lithography. We produced nanoscale hillocks (nanokhobs) on a crystalline Si sub-strate, which can be considered as nanoantennas enhancing STM-LE effect. Our experiments show that the nanoknobes formed on the surface of the original substrate did not provide the achievement of the goal. However, in-situ deposition of a 10 nm thick additional layer of un-doped Si resulted in the increase of STM-LE quantum efficiency by an order of magnitude in comparison with original substrate. This effect paves the way for the fabrication of nanoscale electrically-driven light sources required for hybrid optoelectronic chips.

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.

A technique for synthesizing nanostructures by current lithography in a scanning tunneling microscope (STM lithography) in layered Au/Si structures has been developed. An experimental dependence of the geometric dimensions of the created nanostructures on the time of current STM lithography has been obtained. A theoretical model for the growth of nanostructures is proposed, which explains the nonlinear dependence of the radius of the obtained nanostructures on time with saturation in the region of large radii. Keywords: Au/Si nanostructures, STM lithography, growth rate, modeling.

A technique for synthesizing nanostructures by current lithography in a scanning tunneling microscope (STM lithography) in layered Au/Si structures has been developed. An experimental dependence of the geometric dimensions of the created nanostructures on the time of current STM lithography has been obtained. A theoretical model for the growth of nanostructures is proposed, which explains the nonlinear dependence of the radius of the obtained nanostructures on time with saturation in the region of large radii. Keywords: Au/Si nanostructures, STM lithography, growth rate, modeling.

Microdisk lasers that support whispering gallery modes are very prospective devices in modern nanophotonics due to high Q-factors and low lasing generation thresholds. One of the main fundamental problems of these lasers is the low efficiency of the radiation outcoupling. Moreover, the radiation of the disks propagates mainly in the plane of the disk, whereas in some applications, a vertical radiation outcoupling is required. In this work, we use resonant dielectric nanospheres for the microdisks radiation outcoupling. We have determined the radii at which the radiation outcoupling is most efficient. After transferring a particle to the surface of the disks, we found that the particle shifted the spectral position of the disk's resonances relative to their original position on the value less than 1 nm and reduced the thresholds of lasing on approximate to 20 %, without broadening the line. Finally, we measured directivities from such disks and observed that nanoantennas results in appearance if the directed emission

Integrated photonics requires compact electrically driven sources of optical radia-tion for the use in high-performance integrated circuits with optical interconnections in a chip. Light-emitting tunnel junctions represent a promising option of such nanosized light sources, even if their present quantum efficiency is insufficient for practical implementation. We pro-pose a technique for fabrication of such junctions by ultrahigh vacuum forming of thin silver films. Testing showed a high quality and high optical response of the produced films. Such films can serve as substrates for more complicated tunnel junction structures with yet higher quantum efficiency.

A micro- or nanosized electrically controlled source of optical radiation is one of the key elements in optoelectronic systems. The phenomenon of light emission via inelastic tunneling (LEIT) of electrons through potential barriers or junctions opens up new possibilities for development of such sources. In this work, we present a simple approach for fabrication of nanoscale electrically driven light sources based on LEIT. We employ STM lithography to locally modify the surface of a Si/Au film stack via heating, which is enabled by a high-density tunnel current. Using the proposed technique, hybrid Si/Au nanoantennas with a minimum diameter of 60 nm were formed. Studying both electronic and optical properties of the obtained nanoantennas, we confirm that the resulting structures can efficiently emit photons in the visible range because of inelastic scattering of electrons. The proposed approach allows for fabrication of nanosized hybrid nanoantennas and studying their properties using STM.

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.

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.

Electrically driven plasmonic nanoantennas can be integrated as a local source of the optical signal of advanced photonic schemes for on-chip data processing. The inelastic electron tunneling provides the photon generation or launch of surface plasmon waves. This process can be enhanced by the local density of optical states of nanoantennas. In this paper, we used scanning tunnel microscopy-induced light emission to probe the local optoelectronic properties of single gold nanodiscs. The electromagnetic field distribution in the vicinity of plasmonic structures was investigated with high spatial resolution. The obtained photon maps reveal the nonuniform distribution of electromagnetic near-fields, which is consistent with nanoantenna optical modes. Also, the analysis of derived I(V) curves showed a direct correlation between the nanoantenna optical states and the appearance of features on current-voltage characteristics.

Hight-speed optical nanoemitters are of importance for on-chip optical data processing. A tunnel junctions can be a base for such light emitters, however such structures suffer from low quantum efficiency. One of the ways to improve efficiency of tunneling electron energy to photon generation conversion is the increase of the local density of optical states by using of optical nanoantennas. In this work, we study optoelectronic properties of single gold nanodisc with high spatial resolution. We show nonuniform distribution of electromagnetic near-fields of nanodisk, which is consistent with nanoantenna optical modes. And we demonstrate direct correlation between nanoantenna optical states and features on current-voltage characteristics of tunnel junction between metal tip and nanodisk.

Using of inelastic electron tunnelling is very promising approach to study of subwavelength photons and plasmons sources. Such sources are very important for improving of on-chip data processing. One of the ways for development of efficient and compact optical electrically-driven sources is using of nanoantenna placed into the tunnel junction. In this work, singe optical nanoantenna was investigated under ultra-high vacuum and ambient conditions. Photon maps of nanoantenna excited under scanning tunnel microscope tip was observed and the obtained results was compared with the theoretical predictions of electromagnetic near-field distribution.

This work is devoted to the study of plasmonic properties of electrically driven gold nanodisks employing scanning tunnel microscopy induced luminescence (STML). Gold disks were fabricated with the use of e-beam lithography. The size of the disks (diameter of 120-180 nm and height of 60 nm) was comparable with the wavelength emitted. To confirm that the observed emission of photons is associated with inelastic tunneling of electrons, but not with the collision of the probe with the nanodisk surface, the nanodisk was STML scanned at different angles of the probe motion (0, 90, 270 degrees). In all cases the obtained images were identical. It was shown that nanodisk provided nonuniform STML map, the edges of the nanodisk emitted light with higher intensity compared to the center. Also, current-voltage I(V) characteristics at different points of a nanodisk were obtained and analyzed, and the acquired features at I(V) curves were correlated to the STML results. The proposed approach based on I(V) curves analyzing is very promising for the indirect study of optical properties of the electrically driven nanoscale photon sources.

Abstract Inelastic electron tunneling in a tunnel junction may be used as an electrical nanosource of surface plasmon polaritons and photons. In this work, we investigate emission from tunnel contact between the Platinum/Iridium tip and a thin Au film on glass. The experiment has shown that the intensity of this emission can be enhancement by use a gold nanoantenna located in the vicinity of tunnel contact.

In this paper, we study light emission from a tunnel contact between the Au film on a glass substrate and the Au-coated tungsten probe of the scanning tunneling microscope at ambient conditions. We investigate the dependence of the intensity of the collected optical signal on the film surface morphology, namely, on geometrical parameters of nanometer-scale gold grains (islands) constituting the film. We reveal that the magnitude of inelastic tunnel current and thus photon emission intensity increase both with the decrease of island height and the increase of island width. We show that the difference in the optical emission intensity could reach 4 orders of magnitude for poly- and monocrystalline (atomically flat) samples. The observed phenomena are explained with dependence of the effective area of a tunnel contact on the grain aspect ratio. The obtained results demonstrate the crucial role of the sample morphology in influencing the efficiency of photon emission from the tunnel junction.

Herein, I(V) characteristics of the tunnel junction between the scanning tunneling microscopy (STM) Pt/Ir probe and atomically flat Au film on mica using ultrahigh vacuum STM is investigated. To ensure cleanness and flatness of the Au films, optimization of the substrate annealing and Ar plasma treatment are performed. The obtained technological parameters allow to drastically improve the reproducibility of I(V) measurements. The analysis of I(V), d2I/dV2 (V), and Fowler–Nordheim plots is conducted, and the presence of the features in the bias region near 1.8 V in the form of peak and minimum, peak and anomalous extra minimum, respectively is demonstrated. The direct optical measurements confirm that the features on I(V) curves are associated with the generation of photons from the STM probe‐sample gap, governed by inelastic tunneling processes. The proposed I(V) analysis approach is used for indirect sensing and investigation of the light emission in the tunnel junction offering a powerful tool for the studies of the photonic sources with deeply subwavelength dimensions.

In this paper we investigate light emission in a tunnel junction between a thin gold film on a glass substrate and a gold-coated tungsten tip of a scanning-tunneling microscope probe. The experiments show that the size of grains in the gold film surface dramatically affects the intensity of emissions. We demonstrate that a decrease in the grain aspect ratio provides an increase in the quantum yield of the tunnel-junction emission.