文摘
The electromagnetic interference (EMI) shielding of reduced graphene oxide (MRG), B-doped MRG (B-MRG), N-doped MRG (N-MRG), and B鈥揘 co-doped MRG (B鈥揘-MRG) have been studied in the Ku-band frequency range (12.8鈥?8 GHz). We have developed a green, fast, and cost-effective microwave assisted route for synthesis of doped MRG. B鈥揘-MRG shows high electrical conductivity in comparison to MRG, B-MRG and N-MRG, which results better electromagnetic interference (EMI) shielding ability. The co-doping of B and N significantly enhances the electrical conductivity of MRG from 21.4 to 124.4 Sm鈥? because N introduces electrons and B provides holes in the system and may form a nanojunction inside the material. Their temperature-dependent electrical conductivity follows 2D-variable range hopping (2D-VRH) and Efros鈥揝hklovskii-VRH (ES-VRH) conduction model in a low temperature range (T < 50 K). The spatial configuration of MRG after doping of B and N enhances the space charge polarization, natural resonance, dielectric polarization, and trapping of EM waves by internal reflection leading to a high EMI shielding of 鈭?2 dB (鈭?9.99% attenuation) compared to undoped MRG (鈭?8 dB) at a critical thickness of 1.2 mm. Results suggest that the B鈥揘-MRG has great potential as a candidate for a new type of EMI shielding material useful in aircraft, defense industries, communication systems, and stealth technology.