Enhancement of the Optoelectric and Photovoltaic Responses of Al/PVP:ZnTiO3/p-Si Structure by Graphene Nanoparticles

Abstract

In this work, the optoelectronic response of Al/p-Si photodiodes (PDs) with and without (PVP:Gr-ZnTiO₃) composite interlayer is investigated in dark and under various light intensities (P). The manufacturing/surface preparation is thoroughly explained. The electric/optic parameters including leakage/saturation current (I₀), series/shunt resistances (R_s/R_sh), barrier height (BH), ideality factor (n), energy-dependent density distribution of surface/interface levels (N_ss), photoinduced current (I_ph), photosensitivity (S), optical responsivity (R), and specific detectivity (D*) are calculated from the I–V data in dark and under illumination intensities. Raising the light intensity results in a drop in Φ_B0 and R_s quantities while increasing the I₀ and n values due to photogenerated electron–hole pairs under illumination. The Φ_B0-P and Φ_B0-n graphs are used to calculate the illumination factor and the Φ_B0 in the ideal form. An acceptable linear behavior appears in the I_ph–P profiles for the negative-bias region, where the illumination dependence of photocurrent is explored. It is found that the (PVP:Gr-ZnTiO₃) interlayer leads to an increase in the S, R, and D^* values of the PD to ≈1200, 400 mA W⁻¹, and 1.14 × 10¹⁴ Jones, respectively. These results show that the used (PVP:ZnTiO₃) interlayer displays an excellent photoresponse and may effectively replace conventional PDs for applications in optoelectronic and photovoltaic devices.