Fabrication of a Schottky diodes may include providing a Schottky contact layer containing a low barrier metal layer with spaced apart high barrier metal islands therein on a first surface of a substrate. A diode contact is formed on a second surface of the substrate that is opposite to the first surface. Formation of the Schottky contact layer may include providing a liquid mixture of a high barrier metal and a low barrier metal on the first surface of the substrate. Temperature and/or relative concentrations of the high and low barrier metals in the liquid mixture may be controlled to cause regions of the high barrier metal to solidify within the liquid mixture and agglomerate to form the spaced apart high barrier metal islands while inhibiting solidification of the low barrier metal. The temperature and relative concentrations may then be controlled to cause the low barrier metal to solidify and form the low barrier metal layer containing the high barrier metal islands.