AlN/AlGaInN superlattice light-emitting diodes at 280 nm

Ultraviolet light-emitting diodes operating at 280 nm, grown by gas source molecular-beam epitaxy with ammonia, are described. The device is composed of n- and p-type superlattices of AlN(1.2 nm thick)/AlGaInN(0.5 nm thick) doped with Si and Mg, respectively. With these superlattices, and despite the high average Al content, we obtain hole concentrations of ${\text{(0.7–1.1)×10}}^{18} {\mathrm{cm}}^{\text{−3}},$ with the mobility of 3–4 cm²/V s and electron concentrations of ${\text{3×10}}^{19} {\mathrm{cm}}^{\text{−3}},$ with the mobility of 10–20 cm²/V s, at room temperature. These carrier concentrations are sufficient to form effective $\mathrm{p–n}$ junctions needed in UV light sources.