Photodetectors is a field of study concerned with the fundamental principles, design, fabrication, and characterization of devices engineered to convert optical radiation (photons) into a measurable electrical signal. This research area investigates the physics of light-matter interaction in diverse materials, including semiconductors, metals, and organic compounds, exploring phenomena such as the photoelectric, photoconductive, and photovoltaic effects. Key characteristics under investigation include device sensitivity, spectral response, temporal dynamics (response time), noise performance, quantum efficiency, and linearity across varying incident light levels. The significance of this field resides in its foundational role for numerous technological applications spanning optical communications, spectroscopy, imaging systems, remote sensing, and scientific instrumentation.