Cyclic Voltammetry and Micro-Raman Study of Graphene Oxide-Coated Silicon Substrates

This work presents the improvement of the electro-optical response of n-type crystalline silicon via dip-coated graphene oxide (GO) thin films. GO was deposited on Si/SiO2 by immersion, and the resulting heterostructures were characterized by cyclic voltammetry measurements and Raman spectroscopy. Raman analysis revealed a slight but measurable broadening (~0.7 cm−1) of the Si TO phonon mode at 514 cm−1, indicating local interfacial strain. Cyclic voltammetry measurements showed a substantial increase in photocurrent in comparison to pristine silicon substrates. These effects are attributed to a GO-induced p-type inversion layer and enhanced interfacial charge transfer. The results suggest that GO can serve as a functional interfacial layer for improving silicon-based optoelectronic and photoelectrochemical devices.