JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS, vol.14, pp.41-48, 2012 (SCI-Expanded)
In this study, we have investigated the forward bias current-voltage (I-V) characteristics of Au/n-InP Schottky barrier diodes (SBDs) in the temperature range of 160-400 K. Experimental results show that the values of ideality factor (n), zero-bias barrier height Phi(Bo)(I-V) were found strongly temperature dependent and while the Phi(Bo)(I-V) increases, the n decreases with increasing temperature. Such behavior of Phi(Bo)(I-V) and n is attributed to Schottky barrier inhomogeneities by assuming a Gaussian distribution (GS) of barrier heights (BHs) at Au/n-InP interface. We attempted to draw a Phi(Bo) vs q/2kT plot to obtain evidence of a GS of the BHs, and the values of (Phi) over bar (Bo)=0.89eV and sigma(o) = 0.137 V for the mean barrier height and standard deviation at zero bias, respectively, have been obtained from this plot. Thus, a modified In(I-o/T-2)-q(2)Phi(Bo) (2)/2(kT)(2) vs q/kT plot gives Phi(Bo) and Richardson constant A as 0.904 eV and 10.35 A/cm(2)K(2), respectively, without using the temperature coefficient of the barrier height. This value of the Richardson constant 10.35 A/cm(2)K(2) is very close to the theoretical value of 9.8 A/cm(2)K(2) for n-InP. Hence, it has been concluded that the temperature dependence of the forward I-V characteristics of the Au/n-InP SBDs can be successfully explained on the basis of TE mechanism with a Gaussian distribution of the BHs.