Direct observation of hydrogen passivation of nitrogen-related energy levels in ZnSe and ZnSxSe1-x grown by MBE

The effect of hydrogenation on the electrical properties of N-doped ZnSe an d ZnSxSe1-x films grown by molecular-beam epitaxy is investigated. Hydrogen ation of samples with a net acceptor density (N-a - N-d) around (2-5) x 10( 16) cm(-) 3 decreases the net acceptor density close to the surface and the peak height in deep-level transient spectra of the dominating nitrogen acc eptor with activation energies 110 and 120 meV in ZnSe and ZnS0.08Se0.82 th in films, respectively. Samples with N-a - N-d in the 10(17)cm(-3) range di d not exhibit such changes, while samples with N-a - N-d less than few time s 10(16) cm(-3) became highly resistive. (C) 2000 Elsevier Science B.V. All rights reserved.