Temperature dependent barrier heights in bulk unipolar diodes leading to improved temperature stable performance

Surface states in a Schottky diode lead to a pinning of the Fermi level and a negative temperature coefficient for the barrier height. Calculations show that the barrier height of an epitaxially grown, bulk, unipolar diode actually increases with temperature, typically by about 0.4 meV K^-1 for GaAs between -40 degrees C and +80 degrees C. This novel effect can be used to explain the improved temperature stability of devices employing these diodes as direct retrofit replacements for conventional Schottky diodes.