Modified electrical properties and transport mechanism of Ti/p-InP Schottky structure with a polyvinylpyrrolidone (PVP) polymer interlayer

This paper reviews the electrical and transport properties of Ti/polyvinylpyrrolidone (PVP)/p-InP metal/interlayer/semiconductor (MIS) Schottky diode and compared its results with the Ti/p-InP metal/semiconductor (MS) diode. Analysis results showed that the barrier height (BH) and ideality factor of the MIS diode are found to be improved compared to the MS diode. This indicates that the effective BH is modified by the PVP interlayer since it creates physical barrier between the Ti metal and the p-InP substrate. It is noted that the evaluated BH by Cheung’s and ψ_S-V plots is in good concurrence with one another. Also, the series resistance of the MS and MIS diodes is estimated by Cheung’s functions. The insertion of the PVP interlayer led to a decrease of the interface state density in the Ti/p-InP MS diode. In addition, the relevant junction mechanisms are explained by feasible energy level band diagrams. The Poole–Frenkel emission is the governing conduction mechanism in the Ti/p-InP MS diode. However, at lower voltage region the Poole–Frenkel is conquered, whereas at higher voltage region the Schottky emission is occupied for the Ti/PVP/p-InP MIS diode.