Low- and high-frequency C-V characteristics of the contacts formed by adding a solution of the nonpolymeric organic compound on p-type Si substrate

Al/quercetin/p-Si Schottky barrier diodes (SBDs) have been fabricated by adding a solution of the nonpolymeric organic compound quercetin in ethanol on top of p-Si substrate, and then evaporating the solvent. The quercetin/p-Si contact shows rectifying behaviour and the reverse curve exhibit a weak bias voltage dependence. Barrier height and ideality factor value of 0.86 and 1.06 eV, respectively, for the device have been determined from the forward bias current-voltage (I-V) characteristics. The energy distribution of the interface state density located in the semiconductor band gap at quercetin/p-Si interface ranges from 2.12×1012 cm−2 eV−1 in (0.680−Ev) eV to 4.68×1011 cm−2 eV−1 in (0.813−Ev) eV have been determined from the I-V and the capacitance-voltage (C-V) characteristics (high- and low frequency). The interface state density has an exponential rise with bias from the midgap towards the top of the valence band.