Hydrogen diffusion in zinc oxide thin films was studied by secondary ion mass spectrometry measurements, investigating the spreading of implanted deuterium profiles by annealing. By effusion measurements of implanted rare gases He and Ne the microstructure of the material was characterized. While for material prepared by low pressure chemical vapour deposition an interconnected void structure and a predominant diffusion of molecular hydrogen was found, sputter-deposited ZnO films showed a more compact structure and long range diffusion of atomic hydrogen. Hydrogen diffusion energies of 1.8 to 2eV, i.e. higher than reported in the literature were found. The results were explained in terms of a H diffusion model analogous to the model applied to hydrogen diffusion in hydrogenated amorphous and microcrystalline silicon.

Hydrogen Diffusion in Zinc Oxide Thin Films. Beyer, W., Breuer, U., Hamelmann, F., Hüpkes, J., Stärk, A., Stiebig, H., Zastrow, U.: Materials Research Society Symposium Proceedings, 2010, 1165, 209-14