The Schottky-barrier height of Au on n-Ga1−xAlxAs as a function of AlAs content

The Schottky-barrier height of Au on chemically etched n-Ga1−xAlxAs was measured as a function of x. As x increases, the barrier height rises to a value of about 1.2 eV at x≈0.45, then decreases to about 1.0 eV as x approaches 0.83. The barrier height deviates in a linear way from the value predicted by the ’’common-anion’’ rule as the AlAs mole fraction increases. This behavior is related to chemical reactivity of the Ga1−xAlxAs surface.