X-ray photoelectron spectroscopy of zinc phosphide thin film

X-ray photoelectron spectroscopy (XPS) has been used: to study core level s pectra of electron beam evaporated zinc phosphide (Zn3P2) thin films. The c hemical shifts of XPS core lines (Zn 2P(3/2) and P 2p) and Auger parameter for zinc (beta(Zn) = 2013.9 eV) have been calculated. The results have been used to determine the bond ionicity (similar to 20%) and composition (Zn0. 55P0.45) of the zinc phosphide films. An approximate value for the surface Madelung Constant (alpha(S) = 1.51-1.57) has been obtained for tetragonal z inc phosphide structure. The effect of relaxation on the chemical shift has been found to be relatively small. (C) 1999 Elsevier Science B.V. All righ ts reserved.