In situ Eu doping into Al Ga1−N grown by organometallic vapor phase epitaxy to improve luminescence properties

We have succeeded in situ Eu doping into Al x Ga 1 − x N grown by organometallic vapor phase epitaxy and investigated the effects of the growth pressure and Al composition on the photoluminescence (PL) properties of Eu 3+ ions. The intensity of red emission due to the 5 D 0 – 7 F 2 transition of Eu 3+ ions decreased with increasing Al content in the case of growth at atmospheric pressure. The effect of the reactor pressure on the Eu concentration and Eu 3+ PL properties showed that low-pressure growth is effective in increasing the Eu doping concentration and luminescence efficiency. The PL intensity increased with the Al composition and reached a maximum intensity at approximately x = 0.24. At Al compositions of higher than 0.24, X-ray absorption near-edge structure analysis revealed that the concentration of Eu 2+ ions increased with increasing Al composition, leading to a reduction in the concentration of optically active Eu 3+ ions.