Bolometer detectors are essential for sensing minute energy changes in radiation and are widely used in fields such as astronomy, materials science, and environmental monitoring. Their exceptional sensitivity at cryogenic temperatures enables the detection of extremely small thermal signals, advancing both scientific research and technology. This thesis presents the fabrication and characterization of advanced bolometer architectures based on chemical vapor deposition (CVD) graphene, exploiting its outstanding electrical conductivity, thermal properties, and mechanical strength.
Three major results are demonstrated. First, we report the successful fabrication of quantum dot bolometers using CVD-grown graphene, where the quantum confinement enhances temperature-dependent electrical resistance—an essential parameter for sensitive bolometric detection. Second, a novel design of multi-parallel quantum dot devices based on CVD graphene is fabricated, showing improved scalability and robustness. Third, we reveal that the back-gate voltage plays a critical role in tuning the temperature dependence of the graphene quantum dot resistance, thereby offering a tunable mechanism to optimize bolometer performance.
Importantly, the multi-parallel architecture enables optimization of the total impedance of the bolometer, facilitating its future integration with antennas for high-frequency applications. This design also allows for a significant increase in the total active graphene area while preserving the same level of responsivity, overcoming a common trade-off in miniaturized detectors.
Despite fabrication challenges such as maintaining uniform material properties and achieving high-resolution lithography at the nanoscale, the demonstrated devices pave the way for high-performance, scalable graphene-based bolometers. These advances show promising potential for applications ranging from sensitive detection of molecular magnets to high-resolution DNA sequencing and beyond.