A comparative study on the electrical properties and conduction mechanisms of Au/n-Si Schottky diodes with/without an organic interlayer

Abstract

In order to see an interlayer on the electrical parameters and conduction mechanisms (CMs), both the metal–semiconductor (MS) and Au/(MgO-PVP)/n-Si Schottky diodes (SDs) were grown onto the same wafer with 〈100〉 orientation and 350 μm thickness. Next, their electrical parameters, such as the ideality factor (n), barrier height (ΦB), and series resistances (Rs) were obtained from the current–voltage (I–V) measurements using thermionic emissions, theory, and Cheung and Norde functions and compared. The energy-dependent distribution of interface traps/states (Dit/Nss) of these two structures were extracted from the I–V data in the forward biases by considering the voltage-dependent n and ΦB. Experimental results confirmed that the Nss for a metal–polymer–semiconductor is considerably lower than for an MS, and it increases from the mid-gap towards the edge of the conduction band (Ec). The ln(I)–ln(V) curves have three straight lines which correspond to low, moderate, and high biases, and CM is governed by ohmic, trap/space-charge-limited current, respectively. When comparing these results, MgO-PVP leads to considerably improving the performance of the MS in respect of lower values of Nss, Rs, the reverse saturation current (Io) and higher values of the rectifying rate, ΦB, and the shunt resistance (Rsh), and hence it can be successfully used instead of a traditional insulator interlayer.