Graphene is renowned for its exceptional electrical and mechanical properties; however, its lack of an intrinsic bandgap leads to a limited on/off current ratio, restricting its role as a direct replacement for silicon in logic devices. Nevertheless, its integration with silicon-based platforms offers new opportunities in broadband nanophotonic and optoelectronic applications. This hybrid strategy has the potential to improve the performance of key components such as photodetectors, modulators, and polarizing elements.

In this context, graphene oxide (GO) emerges as a promising material due to its high transparency in the visible range, making it suitable for use as a transparent electrode and optical coating. Here, we investigate the role of dip-coated GO thin films in enhancing the electro-optical response of n-type crystalline silicon. GO layers were deposited via immersion onto Si/SiO₂ substrates, and the resulting heterostructures were characterized through Raman spectroscopy and cyclic voltammetry.

Raman analysis revealed the slight broadening (~0.7 cm⁻¹) of the silicon TO phonon mode at 514 cm⁻¹, indicating the presence of local interfacial strain. Cyclic voltammetry measurements demonstrated a marked increase in the photocurrent compared to uncoated silicon, suggesting improved interfacial charge transfer and the formation of a GO-induced p-type inversion layer. These results highlight the potential of GO as a functional interlayer in the development of advanced silicon-based nano-optoelectronic and photoelectrochemical devices.