Nanoscale Electrically Driven Light Source Based on Hybrid Semiconductor/Metal Nanoantenna

Abstract

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.

The Luminescence Hypothesis of Olfaction

“…Light emission by IET has been known for many years [ 36 ] and can be from single or from higher-order multielectron inelastic tunneling [ 37 ]. The phenomenon of light emission via the inelastic tunneling of electrons through potential barriers or junctions has been used in the development of micro- or nanosized electrically controlled sources of optical radiation for use in optoelectronic systems [ 38 ] to develop miniaturized light sources and ultradense photonic instruments in the visible and near-infrared spectrum [ 39 ] in research and development of optical antennas [ 40 ] and scanning tunneling microscopy. Scanning tunneling microscopy photon emission through IET is known as scanning tunneling microscopy-induced luminescence and is useful for the study of the intrinsic luminescence of molecules in their chemical environments as well as allows charge transfer to be monitored with submolecular resolution [ 41 ].…”

Electrically Driven Plasmons in Metal–Insulator–Semiconductor Tunnel Junctions: The Role of Silicon Amorphization

“…Electrically driven plasmons (EDP) in metal–insulator–metal (MIM) structures , have been studied extensively in both theoretical and experimental frameworks. − Inelastic tunneling of electrons in these structures subjected to a voltage V may excite a surface plasmon with an energy ℏω ≤ eV , which can scatter at the surface and yield a far field photon. The appeal of integrating plasmonic devices in ultrafast communication and their potential application as effective on-chip emitters with electrically tunable spectra have triggered exploration of methods for realization of EDP devices in metal–insulator–semiconductor (MIS) structures. − Plasmon generation in such structures occurs as a result of inelastic tunneling of electrons from the metal layer into unoccupied states in the semiconductor, which are in either the conduction or valence bands.…”

Femtosecond Laser-Printed Gold Nanoantennas for Electrically Driven and Bias-Tuned Nanoscale Light Sources Operating in Visible and Infrared Spectral Ranges

“…Scanning the surface, an STM provides the acquiring of STM induced light emission (STM-LE) maps, thus actually allowing the visualization of LDOS distributions. , Moreover, the STM-LE techniques suit for investigation of not only the local effects but also collective ones, supported by the array of nanoantennas. In previous papers, , it was proposed to use different plasmonic nanoantennas introduced in the STM tunneling gap region as a way to enhance the external quantum efficiency (EQE) of STM-LE by increasing the LDOS (Figure a). It has been shown that plasmonic nanoantennas effectively enhance spontaneous emission of quantum emitters via the Purcell effect, which makes them promising for EQE improvement of the LEIT photon sources.…”

“…Visible and near-infrared (NIR) light sources based on the LEIT principle possess exceptional characteristics, such as subnanometer dimensions, radiation wavelength electrically tuned by gap bias voltage, , and ultrafast response times of several femtoseconds limited only by the RC constant of the supply circuit. , However, practical implementation of nanosized LEIT photon sources had long been hampered by insufficient quantum efficiency traditionally shown by such devices. This drawback primarily originated from relatively low local density of optical states (LDOS) in a flat tunnel gap, which led to the predominance of the elastic channel in the electron tunneling process providing no contribution to optical excitation. , The incorporation of nanoantennas in the contact region had greatly enhanced the capabilities of LEIT devices. ,, …”

“…14,15 The incorporation of nanoantennas in the contact region had greatly enhanced the capabilities of LEIT devices. 10,16,17 Note, the transition to the near IR opens up opportunities for operating at 1300 nm, which is the gold standard of telecommunications. Thus, the development of tunable light sources represents a promising and important task.…”