Silicon-based High-Gain Photodetector with A Strong 254-nm Response for Chemical Oxygen Demand (COD) Monitoring in City Sewage Water

Chemical oxygen demand (COD) measurement in city sewage water becomes important for monitoring water pollution. A 254-nm UVC absorption spectrometer is commonly used for such a purpose. In this work, we report on a photodiode-body-biased MOSFET (PD-MOS) based on silicon and as compared with large-area UV-enhanced silicon photodiode being used, the PD-MOS is advantageous in terms of gain and dynamic range, making it a promising candidate for the COD tests.