AlScN as an electron blocking layer in blue light emitting diodes: A first look

Electron blocking layers (EBLs) are instrumental in visible light emitters based on nitride semiconductor heterostructures. AlScN (a) can be lattice-matched to GaN, (b) can be grown at GaN compatible conditions, and (c) offers favorable band offsets required for EBLs, but has not been used in light emitting devices to date. In this work, we test if lattice-matched AlScN can be integrated as an EBL layer in a blue light emitting diode (LED) pn junction heterostructure. We find that blue LED operation with peak electroluminescence (EL) at ∼460 nm can indeed be realized with an AlScN EBL. In the LED with the AlScN EBL, we observe low reverse leakage current density, and ∼6 nm lower full-width at half maximum of the EL peak compared to a control sample. Though the turn-on voltage of the AlScN EBL containing blue LED is high, this demonstration proves its feasibility and provides guidance for improved performance in the future.