A study of oxygen interaction with GaSb cleaved surfaces by work function and photovoltage measurements

Abstract This paper deals with oxygen sorption at room temperature on cleaved GaSb surfaces. The mechanism was studied in the range 10 -1 -10 -4 langmuirs by measuring contact potential differences in the dark and under illumination on well-cleaved and poorly cleaved n- and p-type GaSb, with an ionization gauge either on or off. After a study of the first steps of oxygen sorption and of the Fermi level pinning on n- and p-type GaSb, the results are compared with those of the Spicer-Lindau group and are explained by a model with two surface states, one acceptor state of density N a and one donor state of density N d , with the ratio N a / N d varying during the exposure to oxygen.