Photoluminescence from AlxIn1-xN layers doped with Tb3+ ions

Abstract

AlxIn1-xN films (0 ≤ x ≤ 1) have been sputter deposited and annealed, both without and with terbium co-doping, to obtain a series of matrices whose band gap energies span the range from around 2 eV to 6 eV. The terbium green luminescence spectra (excitation wavelength 230 nm, i.e. 5.4 eV) are measured at room temperature as a function of the aluminium content (band gap route) and of the terbium concentration (concentration route). The green luminescence assumes a maximum of the integrated intensity at a band gap energy of 4.1 eV (x 0.7) which can be argued to result from a resonant energy transfer from the host matrix into the Tb luminescence centres. Furthermore, the dependence of this maximum integrated intensity as a function of the Tb concentration, i.e. of the average distance between the Tb centres, suggests the energy transfer from the host material into the Tb luminescent centres to be due to dipole-dipole interaction via an exciton bound to the centre. © Published under licence by IOP Publishing Ltd 2011.