Gaussian distribution of inhomogeneous barrier height in Au/n-GaP (100) Schottky barrier diodes

Abstract

The current voltage (I-V) measurements of Au/n-GaP Schottky barrier diodes (SBD) were carried out in the temperature range of 80-375 K. The values of zero-bias barrier height (phi(B0)) and ideality factor (n) ranged from 0.29 eV and 3.85 (80K) to 0.82 eV and 1.16 (375K), respectively. Such behavior of phi(B0) and n is attributed to Schottky barrier inhomogeneities by assuming a Gaussian Distribution (GD) of barrier hights (BHs) at Au/n-GaP interface. The phi(B0) vs q/(2kT) plot has been drawn to obtain evidence of a Gaussian distribution of the barrier heights,and values of phi(B0) = 0,97 eV and sigma(0) = 0.10 V for the mean barrier height and zero-bias standard deviation have been obtained from this plot, respectively. Thus a modified In (I-0/T-2) - q(2) sigma(2)(0) /2k(2)T(2)vs 1000/T plot has given mean barrier height phi(B0) and Richardson constant (A*) as 1.95 eV and 0.054 A cm(-2) K-2, respectively. The temperature dependence of the I-V characteristics of the Au/n-GaP Schottky diode have been successfully explained on the basis of thermionic emission (TE) mechanism with GD of the Schottky barrier heights (SBHs).