A comparative study on current/capacitance: voltage characteristics of Au/n-Si (MS) structures with and without PVP interlayer

Abstract

In order to determine the Polyvinylpyrrolidone (PVP) effect on electrical characteristics, Au/n-Si (MS) structures with and without PVP interfacial layer were fabricated. After that their main electrical parameters were extracted from the forward and reverse biases I–V, and C/G–V measurements at room temperature. The experimental characteristics (I–V) show the MPS structure with high rectification ratio (RR = I_F/I_R at ± 4V), shunt resistance (R_sh) and zero-bias barrier height (Φ_B0) and lower leakage current, ideality factor (n), surface states (N_ss) compared with the MS structure. RR and the reverse saturation current (I_o) for MPS are 55 times higher and 54 times lower than RR and I_o for MS, respectively. The voltage dependent n, effective barrier height (Φe) and energy dependent profile of N_ss for two types structures are acquired by considering the forward biases I–V data. They were found vary from 1.074 × 10¹² eV⁻¹cm⁻² (at E_c − 0.821 eV) to 3.55 × 10¹³ eV⁻¹cm⁻² (at E_c − 0.409 eV) for MPS and 3.85 × 10¹³ eV⁻¹cm⁻² (at E_c − 0.724 eV) to 5.67 × 10¹³ eV⁻¹cm⁻² (at E_c-0.405 eV) for MS structure. R_s, n and Φ_B0 parameters were also found from the Cheung function as 272.4 Ω, 6.17, and 0.964 eV for MPS and 79.2 Ω, 3.38, and 0.708 eV for MS structure as second way. Some electrical parameters of the structures such as concentration of donor atoms (N_D), Fermi energy level (E_F) and BH were also found reverse bias C⁻²–V characteristics for 100 kHz. The use of PVP polymer interlayer considerably improves the efficiency of the MS structure. The way to replace the traditional insulator interlayer concluded as; reducing the N_ss alternatively, leakage current and increase of RR, Φ_B0, and R_sh, respectively.