Photoluminescence and cathodoluminescence of GaN doped with Pr

We report on our observation of visible photoluminescence and cathodolumine scence of Pr-implanted GaN. The implanted samples were subjected to isochro nal thermal annealing treatments at a temperature of 1100 degrees C in N-2 at atmospheric pressure to recover from implantation damage and activate th e rare earth ions. The sharp characteristic emission lines corresponding to Pr3+ intra-4f(n)-shell transitions are resolved in the spectral range from 400 to 1000 nm and observed over the temperature range from 12 to 335 K. W e have developed an energy level diagram for Pr3+ ions in GaN using recorde d spectra. The photoluminescence decay kinetics measurements of P-3(1), P-3 (0), and D-1(2) levels and quenching mechanism analysis allow us to conclud e that the dominant de-excitation process is of electric dipole-electric qu adrupole type. We found also that the D-1(2) level separated from the upper P-3(0) level by 3755 cm(-1) energy gap can be populated in several ways, b y direct energy transfer processes, cross relaxation \P-3(0),H-3(4)]-->\D-1 (2),H-3(6)] and cascade processes from the P-3(0) or higher levels. The ful l width at half maximum of the strongest photoluminescence line at 653 nm, the P-3(0) level, is 2.9 meV at 13 K, with a 1.86 meV blue peak shift in go ing from 13 to 330 K temperature, while the line at 670 nm, P-3(1) level, h as a full width at half maximum of 4 meV at 13 K and a 1.6 meV red peak shi ft. The thermal stability of GaN:Pr3+ epilayers indicates the suitability o f this material for visible optoelectronic devices. (C) 2000 American Insti tute of Physics. [S0021-8979(00)01613- 3].