GaN/Al0.12Ga0.88N and Ga0.99Gd0.01N/Al0.12Ga0.88N multiquantum
well samples with the quantum well thickness of
one nm were grown by a radio-frequency plasma-assisted
molecular-beam epitaxy on GaN (0001) templates. The
epitaxial growth is established in the grown samples. Gd
doped multi-quantum well samples show magnetic behaviour
at room temperature. Photoluminescence measurements
show a strong photoluminescence at the higher
energy side of GaN excitonic peak for the GaN multiquantum
wells. A new luminescence peak at 3.598 eV
was found for Gd doped GaN multi-quantum wells. This
photoluminescence peak is attributed to the formation of
an exciton–polaron in the distorted regions around the Gd
dopants in GaN multi-quantum wells.