Camphor-Based CVD Graphene Integrating CsPbBr₃ Quantum Dots for High-Temperature Endurance, High Flexibility, and Fast Optical Switch Photodetection

Photodetectors (PDs) based on camphor-based CVD graphene integrating CsPbBr 3 quantum dots (QDs) have been fabricated on mica substrates successfully, showing temperature resistant, foldable, and fast response properties. The graphene synthesized from eco-friendly camphor was transferred onto mica substrates, and then the CsPbBr 3 QDs were coated onto the graphene surface to form CsPbBr 3 QDs/graphene composition on a flexible mica substrate. According to the Raman spectrum, the structure of camphor-based CVD graphene is multilayer. The photoresponse of CsPbBr 3 QDs/graphene composition was revealed by temperature-dependent (ranging from 300 K to 523 K) I-V measurements with/without white light illumination (light intensity: 112 mW/cm 2 ). To highlight the temperature resistance of PDs based on CsPbBr 3 QDs/graphene composition, a photo-to-dark current ratio (PDCR) of at 5 V is estimated at different temperatures. The PDCR of the CsPbBr 3 QDs/graphene composition-based PD decreased from 3.2 to 0.74 with increasing temperature from 300 K to 523 K. Moreover, after 0 to 300 bending cycles, the vibration of PDCR value at 5 V is small (from 4.3 to 3.7), showing the high flexibility of the CsPbBr 3 QDs/graphene composition-based PD. Furthermore, we found that the rise and fall times of the CsPbBr 3 QDs/graphene composition-based PDs when we switched the illumination source ON and OFF are ~ 2 and ~1 ms, respectively, indicating fast optical switch behavior. In this study, camphor-based CVD graphene incorporating CsPbBr 3 QDs composition-based PD is demonstrated to exhibit high-temperature resistance, high flexibility, and fast response photodetection.