Near infrared (1.54 mu m) luminescence properties of erbium doped gallium nitride

The photoluminescence (PL) properties of in-situ Er doped GaN prepared by m etalorganic molecular beam epitaxy (MOMBE) have been investigated. The GaN: Er films were grown on sapphire or silicon substrates. The oxygen and carbo n background concentrations in the films were measured to be in the order o f similar to 10(20) and similar to 10(21) cm(-3), respectively. Both types of GaN:Er samples showed intense 1.54 mu m PL at room temperature under bel ow-gap optical excitation. For above-gap excitation, a greatly reduced Er3 luminescence intensity was observed. Pump intensity dependent PL studies r evealed that the Er3+ excitation efficiency under above-gap excitation is r oughly a factor of similar to 30 smaller compared to below-gap excitation. Based on the efficient Er3+ below-gap excitation process a hybrid GaN:Er/sa pphire/InGaN LED was developed. (C) 2000 Elsevier Science S.A. All rights r eserved.