The double Gaussian distribution of barrier heights in Au/n-GaAs Schottky diodes fromI–V–Tcharacteristics

The current–voltage ( I – V ) and capacitance–voltage ( C – V ) characteristics of Au/ n -GaAs contacts have been measured in the temperature range of 80–300 K. An abnormal decrease in the experimental BH Φ b and an increase in the ideality factor n with a decrease in temperature have been observed. This behaviour has been attributed to the barrier inhomogeneities by assuming a Gaussian distribution of barrier heights at the metal–semiconductor interface. The temperature-dependent I – V characteristics of the Au/ n -GaAs contact have shown a double Gaussian distribution giving mean barrier heights of 0.967 and 0.710 eV and standard deviations of 0.105 and 0.071 V, respectively. A modified ln( I 0 / T 2 ) − q 2 σ 2 s /2 k 2 T 2 versus 1/ T plot for the two temperature regions then gives and A * as 0.976 and 0.703 eV, and 13.376 and 8.110 A cm −2 K −2 , respectively. Furthermore, a value of −0.674 meV K −1 for the temperature coefficient has been obtained, and the value of −0.674 meV K −1 for the Au/ n -GaAs Schottky diode is in close agreement with those in the literature.