Origins of Visible Light Emission upon Resistive Switching in NbO₂

Future computing aims to integrate both electrical and optical components to gain high on-chip functional density. Here we present the discovery of a light emission occurring simultaneously with neuron-like resistive switching in electrical devices made of NbO₂, a Mott insulator-metal-transition material [1]. We uncover that upon resistive switching, the NbO₂ device emits light, with a peak in the visible wavelengths, measured via in-situ emission spectroscopy. We evaluate the measured emission spectra against pure blackbody models to understand their possible thermal origins. Further, we perform in-situ Raman spectroscopy during electrical switching, calibrated with ambient-temperature-controlled NbO₂ films, to investigate electronic origins of the observed light emission. We rely upon previously reported band structure for these NbO₂ thin films to assess our findings [2]. Our conclusion illustrates the possible thermal and electronic origins of light emission observed in electrically-switched NbO₂. This discovery of an unprecedented light emission coupled with neuron-like switching in NbO₂ has potential applications for metrology, electro-optical transduction, and on-chip light sources.

[1] Zhou et al., Proc. IEEE 103, 1289 (2015)

[2] Wong et al., Phys. Rev. B 90, 115135 (2014)