Current-voltage characteristics of AlxGa1−xAs Schottky barriers and p-n junctions

Studies of temperature-dependent current-voltage (I-V) characteristics of AlxGa1−xAs Schottky barriers and p-n junctions indicate a gradual departure from theoretical behavior with decrease in temperature. The diode ideality factor n, which takes values between 1 and 2 at room temperature, increases to values between 1.5 and 4 at 94 K. It is shown that, if the ideality factor-ambient temperature product is replaced by an appropriate effective temperature T*, the I-V data appear to obey the theoretical formula at all temperatures. It is also shown that the 1-kT I-V characteristic of a p-n diode can be described either by standard diffusion or thermionic emission theory. This enables one to determine the barrier heights of p-n diodes from their 1-kT I-V plots.