Reliable and precise determination of interface states in metal–insulator–polymeric semiconductors devices

Abstract

The major objective of this manuscript is to develop an integrable capacitance-voltage (C-V) model for the extraction of the interfacial states at p-type polymeric semiconductor-insulator-metal (MIPS) capacitors. A polymeric P3HT (3-hexylthiophene) semiconductor-insulator-metal device was fabricated, firstly. Then, an integrable C-V model was developed. The model was based on Fermi-Dirac distribution for holes and experimental C-V of the p-type polymeric MIS. By the least square nonlinear curve fitting, good matches are presented between theoretical and experimental C-V plots for our p-type P3HT MIS capacitor. With nonlinear regression technique, the capacitance of polymeric MIS not only can be explained via voltage, but also can be predicted by frequency. Hence, the static C-V of polymeric MIS was successfully extracted and therefore the surface state density of polymeric MIS was evaluated via quasi-static technique. Because the suggested model is integrable, surface potential and the interfacial state density can be obtained with reliable, precise and simple method and over whole range of the energy gap on polymeric MIS in explicit functional form for the first time. The linear and non-linear electric potential were determined by applying integral of C-V model over whole voltage. The amount of the charge in channel region was determined by integrating model of C-V over all surface potential. This C-V model has been used to detect the charge on per unit area in channel too. Evidence is presented suggesting that more electrical information of polymeric MIS can be obtained via analysis on C-V characteristics using the suggested model.