Experimental measurements and characterising of photodiodes

Photodetectors, widely employed in optical communication, automatic control, and consumer electronic devices, are a type of optical component. The performance requirements of photodetectors vary depending on their applications. To enhance these devices, certain parameters such as the thickness of different layers and doping levels in each layer are necessary. However, this information is often not provided by manufacturers' datasheets. In this project, a reverse engineering approach was utilized to investigate the relationship between device design and performance by analyzing three different commercial devices through measurement techniques including I/V characteristics, C/V measurements, and spectral response-wavelength analysis. These measurement results were used to extract structural information about the devices. Through this process, it was concluded that depletion region thickness plays a crucial role in dark currents; smaller depletion regions result in lower dark currents. Additionally, potential issues influencing measurement outcomes were also addressed.