The possible current-conduction mechanism in the Au/(CoSO4-PVP)/n-Si junctions

The possible current-conduction mechanism (CCMs) of the Au/CoSO4-PVP/n-Si junctions was investigated using temperature-dependence current-voltage (I-V) experiments over 100-360 K. The experimental results showed that the value of BH increases approximately linearly with increasing temperature. Such positive temperature coefficient (alpha = Delta phi(B0)/Delta T) is in agreement with the reported negative temperature coefficient of the bandgap of Si (= - 0.473 meV/K). The (n(ap)(-1)-1) vsq/2kT curves have different characters in two temperature ranges due to having separate two barrier distributions. The rho(2)and rho(3)values obtained from intercept and slope of these curves as 0.521 V and 0.011 V for 240-360 K temperature range and 0.737 V and 0.004 V for the 100-220 K range. This results show that the high temperature region with smaller rho(2)and larger rho(3)voltage deformation coefficients has a wider and greater of the barrier height distribution than the second region. As an evidence for the Gaussian distribution, the phi(B0)and standard deviation (sigma(0)) were derived from the intercept and slope of the phi(B0)-q/2kT curves as 1.14 eV and 0.163 V at high temperatures and 0.62 eV and 0.088 V at low temperatures. The Richardson constant obtained as 102 A/cm(2)K(2)for 240-360 K temperature range using standard deviation value which is similar to the theoretical Richardson constant value of silicon (112 A/cm(2)K(2)). For each temperature, the profile ofN(ss)vs (E-c-E-ss) was provided using the voltage-dependent effective barrier height (phi(e)) value. It was observed that these surface conditions decreased with increasing temperature.