The effects of (graphene doped-PVA) interlayer on the determinative electrical parameters of the Au/n-Si (MS) structures at room temperature

Abstract

Au/n-Si(MS) and Au/(0.07graphene-PVA)/n-Si(MPS) structures were fabricated on the same wafer at identical conditions and their electrical characteristics have been investigated by using current–voltage (I–V) and capacitance/conductance–voltage(C/G–V) measurements at room temperature. The rectifying rate(RR at ±5 V), barrier height(Φ _Bo ) and surface states(N _ss ) (at 0.5 eV) for MS structure were found from the I–V measurements as 1.96 × 10³, 0.757 eV and 9.67 × 10¹⁴ eV⁻¹ cm⁻² for MS whereas those for MPS structure were 9.67 × 10⁵, 0.790 eV and 1.04 × 10¹³ eV⁻¹ cm⁻², respectively. The reverse current mechanisms were also discussed by considering Poole–Frenkel and Schottky emissions. The values of RR and N _ss of MPS structure are 493.37 times higher and 92.98 times lower than these values of MS structure. The values of doping atoms (N _D ), Fermi energy (E _F ) and BH were extracted from the reverse bias C ⁻² –V characteristics at 1 MHz as 2.42 × 10¹⁵ cm⁻³, 0.260 and 0.994 eV for the MS and 0.856 × 10¹⁵ cm⁻³, 0.234 and 0.828 eV for the MPS structures, respectively. These results show that the use of (graphene-PVA) interlayer improves the performance of MS structure and so it may be good alternative to replace the conventional SiO₂ due to reduce the number of oxygen vacancies and yields low density of N _ss , and increase the BH.