Recent efforts from our labs have focused on the fundamental properties of erbium incorporated into Ge nanowires (Ge NWs) and a diverse number of radial core/shell platforms containing these two elements. In this review we focus on two beneficial outcomes that can be exploited from such structures to even broader families of nanostructures: (a) the useful chemical and photophysical utility of providing wide bandgap oxide shells onto germanium nanowire cores containing rare earth ions such as erbium; (b) the unique combination of germanium and tin in an erbium doped oxide nanowire to engage in a spontaneous oxidation–reduction reaction that enhances the erbium near infrared photoluminescence (PL). A broad range of spectroscopic (PL, PL excitation) and structural (high resolution transmission electron microscopy, scanning electron microscopy, Raman spectroscopy, and energy dispersive X-ray analysis) tools are employed for this evaluation.