Terahertz photoconductive antennas design and modelling from advanced design strategies to nano-fabrication

The demand of high bandwidth and data transmission rate in future wireless communications is one of the most urgent problems in academia. Terahertz (THz) wave is located between the microwave and infrared region, covering a wide bandwidth in which a high potentiality of communication applications is competent. Within this spectrum, the development of THz antennas with enhanced radiation performance has become a major research focus. Photoconductive antennas (PCAs) have emerged as key components in THz systems due to their broad bandwidth, high data transmission rate, and simple structure. However, its low radiation power due to limited optical-to-THz conversion efficiency has been the problem that most plagues the academic world. The motivation of this PhD study is to enhance the performance of THz PCAs through structural and material innovations, and to design and fabricate high-performance PCAs on this basis. Several PCA designs have been designed, modelled, and fabricated, and molybdenum disulfide (MoS2) and graphene quantum dots (GQDs) have been incorporated into the proposed PCAs. Nano-fabrication methods of the proposed PCAs based on novel materials and nano-structures have been successfully completed. Measurements of surface current and THz radiation emission demonstrate the superiority of these proposed PCA designs. The combined research on material research, antenna structural design, successful implementation of nano-fabrication techniques, and the measurements demonstrating enhanced photocurrent and THz emission has not only provided a promising high-performance THz emission source for THz applications but also paved the way for future experimental strategies and performance characterization methods in THz PCA research.