The screening response of a dilute electron gas in core level photoemission from Sb-doped SnO2

The variation of core lineshape with carrier concentration in Sb-doped SnO2 has been studied by high-resolution X-ray photoemission spectroscopy. The Sn 3d core levels display an asymmetric lineshape which may be fitted with components associated with screened and unscreened final states. The separation between the two fitted peaks and the relative intensity of the screened component both increase with increasing carrier concentration. The satellite energies are of the order expected for a screening mechanism involving excitation of plasmons. (C) 2002 Elsevier Science B.V. All rights reserved.