A systematic study of switching, optoelectronics, and gas-sensitive properties of PCF-graphene-based nanodevices: Insights from DFT study

Two-dimensional materials exhibit significant potential and wide-ranging application prospects owing to their remarkable tunability, pronounced quantum confinement effects, and notable surface sensitivity. The switching, optoelectronics, and gas-sensitive properties of the new carbon material poly-cyclooctatetraene framework (PCF)-graphene were systematically studied using density functional theory combined with the nonequilibrium Green's function method. First, the diode device based on PCF-graphene monolayer exhibited an impressive switching ratio of 10⁶, demonstrating excellent diode characteristics. Moreover, in the investigation of the pin junction utilizing monolayer PCF-graphene, it is noteworthy that significant photocurrent responses were observed in both the zigzag and armchair directions, specifically within the visible and ultraviolet regions. Finally, gas sensors employing monolayer and bilayer PCF-graphene demonstrate significant chemical adsorption capabilities for NO and NO₂. Notably, the maximum gas sensitivity for NO is achieved in monolayer PCF-graphene, reaching 322% at a bias voltage of 1.0 V. Meanwhile, for bilayer PCF-graphene-based gas sensor, the maximum gas sensitivity reaches 52% at a bias voltage of 0.4 V. In addition, the study also examined the influence of various environmental conditions, specifically H₂O, O, and OH, on the system under investigation. The obtained results emphasize the multifunctional properties of PCF-graphene, exhibiting significant potential for various applications, including switching devices, optoelectronic devices, and gas sensors.