Analysis of current–voltage and capacitance–voltage characteristics of perylene-monoimide/n-Si Schottky contacts

The electrical and interface state properties of Au/perylene-monoimide (PMI)/n-Si Schottky barrier diode have been investigated by current–voltage (I–V) and capacitance–voltage (C–V) measurements at room temperature. A good rectifying behavior was seen from the I–V characteristics. The series resistance (Rs) values were determined from I–V and C–V characteristics and were found to be 160 Ω and 53 Ω, respectively. The barrier height (Φb) of Au/PMI/n-Si Schottky diode was found to be 0.694 eV (I–V) and 0.826 eV (C–V). The ideality factor (n) was obtained to be 4.27 from the forward bias I–V characteristics. The energy distribution of interface state density (Nss) of the PMI-based structure was determined, and the energy values of Nss were found in the range from Ec − 0.508 eV to Ec − 0.569 eV with the exponential growth from midgap toward the bottom of the conduction band. The values of the Nss without Rs are 2.11 × 1012 eV−1 cm−2 at Ec − 0.508 eV and 2.00 × 1012 eV−1 cm−2 at Ec − 0.569 eV. Based on the above results, it is clear that modification of the interfacial potential barrier for metal/n-Si structures has been achieved using a thin interlayer of the perylene-monomide.

► A detailed investigation of some electrical properties of PMI/n-Si contacts has been reported.
► The interface state density of organic–inorganic (PMI/n-Si) contact structures has been reported.
► The values of Φb, n, Nss with and without Rs of contacts have been obtained.
► Series resistance effects on organic–inorganic Schottky diodes have also been investigated.