A compare of electrical characteristics in Al/p-Si (MS) and Al/C20H12/p-Si (MPS) type diodes using current–voltage (I–V) and capacitance–voltage (C–V) measurements

Abstract

In this study, both the metal-semiconductor (MS) and metal-polymer-semiconductor (MPS), (Al/C20H12/p-Si), type Schottky barrier diodes (SBDs) were fabricated using spin coating method and they were called as D1 and D2 diodes, respectively. Their electrical characterization have been investigated and compared using the forward and reverse bias I–V and C–V measurements at room temperature. The main electrical parameters such as ideality factor (n), reverse saturation current (Io), zero-bias barrier height (ΦBo), series (Rs) and shunt (Rsh) resistances, energy dependent profile of interface states (Nss), the doping concentration of acceptor atoms (NA) and depletion layer width (WD) were determined and compared each other and literature. The rectifying ratio (RR) and leakage current (IR) at ±3V were found as 2.06×103, 1.61×10−6A and 15.7×103, 2.75×10−7A for D1 and D2, respectively. Similarly, the Rs and Rsh values of these diodes were found as 544Ω, 10.7MΩ and 716Ω and 1.83MΩ using Ohm’s Law, respectively. In addition, energy and voltage dependent profiles of Nss were obtained using the forward bias I–V data by taking into account voltage dependent effective barrier height (Φe) and n and low-high frequency capacitance (CLF–CHF) methods, respectively. The obtained value of Nss for D2 (MPS) diode at about the mid-gap of Si is about two times lower than D1 (MS) type diode. Experimental results confirmed that the performance in MPS type SBD is considerably high according to MS diode in the respect of lower values of Nss, Rs and Io and higher values of RR and Rsh.