Electroluminescence of the graphene 2D semi-metal

A. Schmitt; L. Abou-Hamdan; M. Tharrault; S. Rossetti; D. Mele; R. Bretel; A. Pierret; M. Rosticher; P. Morfin; T. Taniguchi; K. Watanabe; J. M. Berroir; G. Fève; G. Ménard; B. Plaçais; C. Voisin; J. P. Hugonin; J. J. Greffet; P. Bouchon; Y. De Wilde; E. Baudin

arXiv · 2306.05351

Electroluminescence of the graphene 2D semi-metal

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Abstract

Electroluminescence, a non-thermal radiative process, is ubiquitous in semi-conductors and insulators but fundamentally precluded in metals. We show here that this restriction can be circumvented in high-quality graphene. By investigating the radiative emission of semi-metallic graphene field-effect transistors over a broad spectral range, spanning the near- and mid-infrared, we demonstrate direct far-field electroluminescence from hBN-encapsulated graphene in the mid-infrared under large bias in ambient conditions. Through a series of test experiments ruling out its incandescence origin, we determine that the electroluminescent signal results from the electrical pumping produced by interband tunneling. We show that the mid-infrared electroluminescence is spectrally shaped by a natural quarter-wave resonance of the heterostructure. This work invites a reassessment of the use of metals and semi-metals as non-equilibrium light emitters, and the exploration of their intriguing specificities in terms of carrier injection and relaxation, as well as emission tunability and switching speed.

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A. Schmitt, L. Abou-Hamdan, M. Tharrault, S. Rossetti, D. Mele, R. Bretel, A. Pierret, M. Rosticher, P. Morfin, T. Taniguchi, K. Watanabe, J. M. Berroir, G. Fève, G. Ménard, B. Plaçais, C. Voisin, J. P. Hugonin, J. J. Greffet, P. Bouchon, Y. De Wilde, E. Baudin. 2023-06-08. Electroluminescence of the graphene 2D semi-metal. https://arxiv.org/abs/2306.05351

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