Upconversion luminescence has been obtained from Er-implanted GaN films by focused-ion-beam (FIB) direct write. FIB implantation was performed on GaN films grown by molecular beam epitaxy, hydride vapor phase epitaxy, and metalorganic chemical vapor deposition. After implantation, the GaN samples were annealed at 1100 °C for 1 h in various ambients (Ar, N2, and O2). Strong green upconversion was observed at 523 and 546 nm under red (840 nm) and infrared (1.0 μm) excitation. Upconversion intensity was measured for Er doses ranging from 4.3×1012 to 2.4×1016 atoms/cm2. Maximum upconversion intensity at 546 nm was observed at a dose of 1–2×1015 atoms/cm2, which corresponds to an atomic percentage of 0.3%–0.6%.

Investigations on liquid alloy ion sources for rare-earth elements (abstract) Rev. Sci.We have developed procedures for the fabrication of Er-Ni and Pr-Pt liquid alloy ion sources ͑LAIS͒. Er 2ϩ beam with target current of ϳ100 pA and Pr 2ϩ beams with target current of ϳ200 pA were obtained, which correspond to 50% and 80% of the total target current, respectively. Both Er-Ni and Pr-Pt alloys oxidize quickly once exposed to air. Er-Ni source lifetimes were generally larger than 200 A h. The source lifetimes of Pr-Pt LAISs were approximately 30 A h, limited by oxide contamination and wettability problems. Visible photoluminescence has been observed from Er-or Pr-doped GaN, Al 2 O 3 , and ZBLAN glass using focused ion beam direct write implantation.