Structural and electrical properties of heterojunction devices formed by spinning TIPS Pentacene thin films on n-Si substrates

Heterojunctions were fabricated by spinning triisopropylsilyl (TIPS) Pentacene films on n-Si. The electrical transport measurements reveal that the heterojunctions possess good Schottky-type rectifying capability. The electrical parameters of the devices are derived by applying thermionic emission model. The electrical characteristics of the devices are found to be strongly related to the thickness of TIPS Pentacene film. A high barrier height demonstrated in the device formed with thin TIPS Pentacene can be explained by a low image force lowering and small roughness of the film. The large rectification ratio accompanied with the low reverse saturation current exhibited in the device with thin film may be attributed to this high barrier height formed in the junction. A depletion width in Si was estimated to be ∼860 nm in TIPS Pentacene/Si junctions from the zero-bias capacitance measured at 1 MHz.