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.