Abstract
The history of RF technology can provide human beings a powerful lesson that the infrastructure of modern-day wireless communication depends on the complexity and configurability of silicon-based solid-state devices and integrated circuits. The field of THz technology is undergoing a developmental revolution which is at an inflection point and will bridge the ‘technology’ and ‘application’ gap in meaningful ways. This quantitative progress is a result of continuous and concerted efforts in a wide range of areas including solid-state devices, 2D materials, heterogeneous integration, nanofabrication and system packaging. In this chapter, the innovative theoretical approaches that have enabled significant advancement in the field of system-level THz technology are discussed. The focus is kept on the formulation of terahertz conductivity which plays a critical role in the modeling of devices that integrate technologies across electronics and photonics. Further, the findings build on coupling a probe pulse of terahertz illumination into the photoexcited region of amorphous silicon are presented and discussed in detail. Terahertz light has a higher penetration depth for opaque semiconductor materials which provides an accurate method to measure the conductivity of novel materials for the construction of efficient solar cells. This paves the way for the possibility to develop energy systems can address the need for reconfigurability, adaptability and scalability beyond the classical metrics.