The ZnO/ZnCdO/ZnO multiple quantum well samples grown on sapphire substrates by molecular beam epitaxy and annealed in situ were exposed to D2 plasmas at 150C. The D showed migration depths of ~0.8µm for 30min plasma exposures, with accumulation of 2H in the ZnCdO wells. The photoluminescence intensity from the samples was increased by factors of 5 at 5K and ~20 at 300K as a result of the deuteration, most likely due to passivation of competing non-radiative centers. Annealing up to 300C led to increased migration of 2H toward the substrate but no loss of deuterium from the sample and little change in the photoluminescence intensity. The initial photoluminescence intensities were restored by annealing at ≥ 400C as 2H was evolved from the sample (~90% loss by 500C). By contrast, samples without in situ annealing showed a decrease in photoluminescence intensity with deuteration. This suggested that even moderate annealing temperatures led to degradation of ZnCdO quantum wells.

Migration and Luminescence Enhancement Effects of Deuterium in ZnO/ZnCdO Quantum Wells. W.Lim, D.P.Norton, S.J.Pearton, X.J.Wang, W.M.Chen, I.A.Buyanova, A.Osinsky, J.W.Dong, B.Hertog, A.V.Thompson, W.V.Schoenfeld, Y.L.Wang, F.Ren: Applied Physics Letters, 2008, 92[3], 032103