Interaction of hydrogen with defects in ZnO nanoparticles – studied by positron annihilation, Raman and photoluminescence spectroscopy Xudong Xue, Tao Wang, Xudong Jiang, Jing Jiang, Chunxu Pana and Yichu Wu CrystEngComm, 2014,16, 1207-1216 DOI: 10.1039/C3CE42202J http://pubs.rsc.org/en/content/articlelanding/2014/ce/c3ce42202 Thank you very much.