Eur. Phys. J. Appl. Phys. 80, 10101 (2017)
https://doi.org/10.1051/epjap/2017170147

Regular Article

Interfacial layer thickness dependent electrical characteristics of Au/(Zn-doped PVA)/n-4H-SiC (MPS) structures at room temperature

¹ Department of Physics, Faculty of Sciences and Arts, Süleyman Demirel University, Isparta 32260, Turkey
² Department of Physics, Faculty of Science, Bingöl University, Bingöl 12000, Turkey
³ Department of Physics, Faculty of Science, Gazi University, Ankara 06500, Turkey

^* e-mail: alikokce@sdu.edu.tr

Received: 24 April 2017
Received in final form: 19 July 2017
Accepted: 7 August 2017
Published online: 3 October 2017

Abstract

Au/(Zn-doped PVA)/n-4H-SiC metal/polymer/semiconductor (MPS) structures with different interfacial layer thickness values (50, 150, 500 nm) were fabricated and their electrical characteristics were compared. Their electrical parameters (i.e. reverse-bias saturation current (I_o), ideality factor (n), zero-bias barrier height (BH) (Φ_bo), series and shunt resistances (R_s, R_sh)) were calculated from the forward bias current–voltage (I_F–V_F) data whereas other parameters (i.e. Fermi energy level (E_F), BH (Ф_b) and donor concentration (N_d)) were calculated from the linear part of C⁻²–V characteristics at room temperature. Obtained results confirmed that the values of n, Φ_bo, R_s and R_sh increase with increasing interlayer thickness, and linear correlation between n and Φ_bo was observed. The high values of n for three structures can be ascribed to the presence of an interlayer, surface states (N_ss) and barrier inhomogeneities. The energy density distribution profile of N_ss was obtained from the I_F–V_F data by taking into account voltage-dependent effective BH (Ф_e) and n for each structure. The R_i vs V plot for these structures was obtained using both Ohm's law and Nicollian–Brews method. All these experimental results show that the interfacial layer and its thickness play an important role in main electric parameters of these structures.