  We demonstrate a novel electro-luminescence device in which GaN-based
$\mu$-LEDs are used to trigger the emission spectra of monolayers of transition
metal dichalcogenides, which are deposited directly on the $\mu$-LED surface. A
special $\mu$-LED design enables the operation of our structures even in the
limit of low temperatures. A device equipped with a selected WSe$_2$ monolayer
flake is shown to act as a stand-alone, electrically-driven single-photon
source.
