JOURNAL OF APPLIED PHYSICS, vol.108, no.6, 2010 (Peer-Reviewed Journal)
The forward bias current-voltage (I-V) characteristics of Au/n-Si Schottky barrier diodes (SBDs) with Zn doped poly (vinyl alcohol) (PVA:Zn) interfacial layer have been investigated in the wide temperature range of 80-400 K. The conventional Richardson plot of the ln(I-o/T-2) versus q/kT has two linear regions: the first region (200-400 K) and the second region (80-170 K). The values of activation energy (E-a) and Richardson constant (A*) were obtained from this plot and especially the values of A* are much lower than the known theoretical value for n-type Si. Also the value of E-a is almost equal to the half of the band gap energy of Si. Therefore, the Phi(ap) versus q/2kT plot was drawn to obtain the evidence of a Gaussian distribution (GD) of barrier heights (BHs) and it shows two linear region similar to ln(I-o)/T-2 versus q/kT plot. The analysis of I-V data based on thermionic emission of the Au/PVA:Zn/n-Si SBDs has revealed the existence of double GD with mean BH values (Phi(B0)) of 1.06 eV and 0.86 eV with standard deviation (sigma) of 0.110 eV and 0.087 V, respectively. Thus, we modified ln(I-o/T-2)-(q sigma)(2)/2(kT)(2) versus q/kT plot for two temperature regions (200-400 K and 80-170 K) and it gives renewed mean BHs (Phi) over bar (B0) values as 1.06 eV and 0.85 eV with Richardson constant (A*) values 121 A/cm(2) K-2 and 80.4 A/cm(2) K-2, respectively. This obtained value of A* = 121 A/cm(2) K-2 is very close to the known theoretical value of 120 A/cm(2) K-2 for n-type Si. (C) 2010 American Institute of Physics. [doi:10.1063/1.3468376]