In this talk, I will present a multifunctional platform based on 2D-material tunnel junctions for nanoscale light sources, detectors, sensors and memristive devices. I will show that in graphene-based junctions, inelastic electron tunneling couples efficiently to excitons in low-dimensional materials via near-field electromagnetic interactions, without direct charge injection into the optically active layer [1,2]. This Förster-type energy-transfer process enables exciton excitation with efficiencies up to four orders of magnitude higher than photon-mediated coupling [1] and is governed by the local electromagnetic environment and photonic density of states of the junction.

I will show how this platform enables electrically driven electroluminescence from a wide range of emitters, including TMD monolayers, colloidal quantum dots, perovskite nanocrystals, and molecular dyes, through simple integration with graphene-based junctions. Moreover, tunneling-driven energy transfer enables multi-electron processes that allow sub-bandgap exciton generation and nonlinear excitation pathways enhanced by the local density of states [3] and can be extended to exciton-polariton generation in magnetic 2D materials such as CrSBr, leading to polarized electroluminescence [4]. On the detection side, energy-transfer-mediated coupling enhances photodetector performance, boosting the photoresponse of a MoSe₂ junction by more than 18x using a WS₂ antenna layer [5]. Finally, I will briefly discuss about how tunnel junctions coupled to optical antennas can work as self-illuminated plasmonic sensors [6] and how high electric fields in ultrathin 2D tunnel barriers enable controllable non-volatile memristive behavior through defect engineering of MoS₂ [7].

[1] S. Papadopoulos et al., arXiv:2209.11641 (2022).
[2] L. Wang, S. Papadopoulos, F. Iyikanat et al., Nature Materials 22, 1094 (2023).
[3] S. Shan, J. Huang et al., Nano Letters 23, 10908 (2023).
[4] J. D. Ziegler et al., Science Advances 11, eadz6724 (2025).
[5] Y. Koyaz, S. Papadopoulos et al., ACS Photonics 12, 5390–5398 (2025).
[6] J. Lee, Y. Wu, I. Sinev et al., Nature Photonics, 19, 938–945 (2025).
[7] S. Papadopoulos et al., Physical Review Applied, 18, 014018 (2022).