Abstract
Ultrafast interfacing of electrical and optical signals at the nanoscale is highly desired for on-chip applications including optical interconnects and data processing devices. Here, we report electrically driven nanoscale optical sources based on metal–insulator–graphene tunnel junctions (MIG-TJs), featuring waveguided output with broadband spectral characteristics. Electrically driven inelastic tunneling in a MIG-TJ, realized by integrating a silver nanowire with graphene, provides broadband excitation of plasmonic modes in the junction with propagation lengths of several micrometers (∼10 times larger than that for metal–insulator–metal junctions), which therefore propagate toward the junction edge with low loss and couple to the nanowire waveguide with an efficiency of ∼70% (∼1000 times higher than that for metal–insulator–metal junctions). Alternatively, lateral coupling of the MIG-TJ to a semiconductor nanowire provides a platform for efficient outcoupling of electrically driven plasmonic signals to low-loss photonic waveguides, showing potential for applications at various integration levels.
Original language | English |
---|---|
Pages (from-to) | 3731-3738 |
Number of pages | 8 |
Journal | Nano Letters |
Volume | 23 |
Issue number | 9 |
Early online date | 25 Apr 2023 |
DOIs | |
Publication status | Published - 10 May 2023 |