Interfacial charge-transfer for robust Raman quenching in staggered band aligned n-SnS2/p-rGO heterostructures

Artificial stacking of layered combinations of two-dimensional materials (2D) into van der Waals heterostructures (vdWHs) has opened new avenues in the research world. Here, we fabricated nanohybrids based on transition metal dichalcogenides (TMDs - n-SnS2)/reduced graphene oxide (p-rGO) by layer-by-layer (LBL) method and investigated its structure?property relationship. XRD results indicated the phase transitions from SnS2 to SnS2/SnO2 and GO to rGO with rGO content in these heterostructures. These heterostructures exhibits an allowed direct band-gap which decreases with rGO content. Hall measurements reveal a change in electrical parameters especially the carrier type with rGO content. A unified theory based on Graphene Enhanced Raman Spectroscopy (GERS) is used to explain Raman quenching and the charge-transfer degree has been calculated. The formation of n-SnS2/p-rGO vdWHs Type-II staggered band alignment is demonstrated by X-ray photoelectron spectroscopy (XPS). The formation of staggered gap creates a better platform to understand their basic physical properties to further the development of future electronic devices.

Automated summary

Artificial stacking of two-dimensional materials into van der Waals heterostructures has opened up new research possibilities. Nanohybrids based on transition metal dichalcogenides/reduced graphene oxide were fabricated and their structure-property relationship, electrical parameters, and spectroscopic properties were investigated. The formation of staggered band gap in n-SnS2/p-rGO vdWHs was demonstrated, providing a better understanding of their physical properties for future electronic device development.