“…Effects of ion beams on optical and structural properties of semiconductors such as GaN and related materials are discussed [15][16][17][18][19]. Electronic energy loss of heavy ions in GaN increases the compressive strain as evidenced by HRXRD and Raman characterizations [20]. In the present study, the effects of 80 MeV Ni ions irradiation in GaN and subsequent rapid thermal annealing (RTA) on various luminescence properties have been investigated using photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopy.…”