XPS analysis with depth resolution of chemical bath-deposited ZnSe thin films

X-ray photoelectron spectroscopy analysis of ZnSe thin films deposited by t he chemical bath deposition method is carried out. The composition of the f ilms at the surface and subsurface is determined by angle-resolved XPS dete ction of photoelectrons, and the elemental profile in the whole depth is de termined by sputter-assisted XPS, In general, the films are composed of a m ixture of ZnSe and ZnO (or Zn(OH)(2) for non-annealed films), the relative proportions of which vary depending on the substrate properties and thermal treatments, Also, inhomogeneous depth composition is encountered, the film s richer in ZnO being close to the film/substrate interface, with increasin g ZnSe proportion above. This result is explained in relation to the mechan isms that contribute to film growth in the chemical bath. The characteristi c composition of the films is expected to influence their behaviour as buff er layers for photovoltaic thin-film solar cells. Copyright (C) 2000 John W iley & Sons, Ltd.