Temperature dependence of charge transport in single-layer graphene on surface-terminated diamond

The integration of single-layer graphene with diamond substrates offers a promising platform for high-performance electronic devices by utilizing the exceptional properties of both materials. This study describes a fabrication process and transport measurements of single-layer graphene devices on diamond substrates featuring two surface terminations: hydrogen (H-terminated, thermal process) and oxygen (O-terminated, plasma treatment). The carrier transport properties were investigated using Hall effect measurements over a broad temperature range (80–400 K) under high-vacuum conditions ( 1 × 1 0 − 4 mbar). Our findings reveal that thermal annealing significantly improves the graphene-diamond interface quality, causing a notable increase in carrier mobility for devices on both H- and O-terminated from 1439 to 1644 cm 2 / Vs and from 1238 to 1340 cm 2 / Vs, respectively. We also found that the effect of remote interfacial phonon scattering on high-temperature mobility is affected by the termination type. These findings highlight the importance of substrate surface engineering and offer a pathway for optimizing graphene-diamond heterostructures for advanced electronic applications.