JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS, vol.30, no.9, pp.9029-9037, 2019 (Journal Indexed in SCI)
AbstarctThis study presents electrical characteristics of n-GaAs based Schottky barrier diodes (SBDs) with Rhenium (Re) rectifier contacts. The electrical characteristics of the Re/n-GaAs SBDs were investigated utilizing the forward bias current-voltage (I-F-V-F) data collected in temperature range of 60-400K. The values of ideality factor (n) and zero-bias barrier height (phi(Bo)) were found as 9.10 and 0.11eV for 60K, and 1.384 and 0.624eV for 400K, respectively, on the basis of thermionic-emission theory. The conventional Richardson plot deviated from linearity at low temperatures and the Richardson constant value (A(*)) was obtained quite lower than the theoretical value for this semiconductor (8.16Acm(-2)K(-2)). nkT/q-kT/q plot shows that the field-emission may be dominant mechanism at low temperatures as a result of tunneling via surface states since the studied n-GaAs's doping concentration is on the order of 10(18) cm(-3), i.e. at high values so leads to tunneling. On the other hand, phi(Bo)-n, phi(Bo)-q/2kT and (n(-1)-1)-q/2kT plots exhibit linearity but this linearity is observed for two temperature regions (60-160K and 180-400K) due the presence of double Gaussian distribution (GD) of the barrier height. Therefore, the standard deviation value was obtained from the plot of phi(Bo)-q/2kT and it was used for modifying the conventional Richardson plot into the modified Richardson plot by which the values of mean barrier height and A(*) were obtained as 0.386eV and 15.55Acm(-2)K(-2) and 0.878eV and 8.35Acm(-2)K(-2) for the low and high temperature regions, respectively. As a result, I-F-V-F-T characteristics of the Re/n-GaAs SBDs were successfully elucidated by double-GD of barrier height.