This dataset contains scanning electron microscopy (SEM) images, transmission electron microscopy (TEM) pictures and Catodoluminescence (CL) measurements carried out on AlN and AlGaN/AlN core-shell nanorod. The samples were fabricated via a hybrid top-down/bottom up approach. Displacement Talbot Lithography is used to fabricate Au/Ni metal dots to act as a hard etch mask. Ultrathin AlN nanorod arrays are created; thanks to a two-step dry-wet etching process with first, chlorine-based dry etching of an AlN template and second, KOH-based wet etching. AlN facet recovery and AlGaN quantum well growth is performed by Metal Organic Vapor Phase Epitaxy. TEM and CL were used to assess the structural, chemical and optical quality of the various nanorod samples.