Fabrication and electrical properties of Al/phenolsulfonphthalein/n-Si/AuSb structure

The current–voltage (I–V), capacitance–voltage (C–V) and capacitance–frequency (C–f) characteristics of Al/phenolsulfonphthalein (PSP)/n-Si/AuSb structure were investigated at room temperature. A modified Norde's function combined with conventional forward I–V method was used to extract the parameters including barrier height and the series resistance. The barrier height and series resistance obtained from Norde's function were compared with those from Cheung functions, and it was seen that there was a good agreement between the barrier height values from both method. It was also seen that the values of capacitance were almost independent of frequency up to a certain value of frequency, whereas at high frequencies the capacitance decreased quickly. The higher values of capacitance at low frequencies were attributed to the excess capacitance resulting from the interface states in equilibrium with the n-Si that can follow the alternating current (a.c) signal.