“…Even though recent branches of research on ZnO focus on the realization of photonic devices as well [9,10], scintillation remains one of its primary applications [11,12]. However, detector and scintillator applications based on group III-nitrides are emerging as subjects of dedicated studies too [13][14][15][16], since GaN has a radiation hardness [17] and luminescence time response [18] comparable to ZnO [4,11,12]. Determinations of absolute cathodoluminescence (CL) efficiencies and of radiative constants of GaN and of ZnO grown by metalorganic chemical vapor deposition (MOCVD) remain extremely scarce, even though micro-CL has matured to become a standard tool [19][20][21][22][23].…”