In this paper, we fabricated an Al/new fuchsin/p-Si organic–inorganic (OI) Schottky diode structure by direct evaporation of an organic compound solution on a p-Si semiconductor wafer. A direct optical band gap energy value of the new fuchsin organic film on a glass substrate was obtained as 1.95 eV. Current–voltage (I–V) and capacitance–voltage (C–V) measurements of the OI device were carried out at room temperature. From the I–V characteristics, it was seen that the Al/new fuchsin/p-Si contacts showed good rectifying behavior. An ideality factor value of 1.47 and a barrier height (BH) value of 0.75 eV for the Al/new fuchsin/p-Si contact were determined from the forward bias I–V characteristics. A barrier height value of 0.78 eV was obtained from the capacitance–voltage (C–V) characteristics. It has been seen that the BH value of 0.75 eV obtained for the Al/new fuchsin/p-Si contact is significantly larger than that of conventional Al/p-Si Schottky metal–semiconductor (MS) diodes. Thus, modification of the interfacial potential barrier for Al/p-Si diodes has been achieved using a thin interlayer of the new fuchsin organic semiconductor; this has been ascribed to the fact that the new fuchsin interlayer increases the effective barrier height because of the interface dipole induced by passivation of the organic layer.