Modified electrical characteristics of Pt/n-type Ge Schottky diode with a pyronine-B interlayer

Abstract

The electrical characteristics of a Pt/n-type Ge Schottky diode with a pyronine-B (PYR-B) interlayer prepared by spin coating was investigated by current–voltage (I–V) and capacitance–voltage (C–V) measurements. It was observed that the barrier height of Pt/PYR-B/n-type Ge (0.65eV) was higher than that of the conventional Pt/n-type Ge Schottky diode (0.58eV). This is attributed to the fact that the organic interlayer increases the effective barrier height by influencing the space-charge region of Ge. The introduction of the PYR-B interlayer led to a reduction of the interface state density in the Pt Schottky contact to n-type Ge. The electric field dependence of the reverse leakage current revealed that Schottky emission and Poole–Frenkel emission mechanisms dominated the reverse current in the Pt/n-type Ge and Pt/PYR-B/n-type Ge Schottky diodes, respectively.