Photodiode Development for Fluorescence Spectroscopy Applications

Two photodiode architectures were designed, built, and tested for comparison for implementation into a fluorescence spectroscopy, or fluorometric, system. All devices were fabricated on 4-inch, N-type silicon substrates. The photodiodes presented were tested for responsivity and response time, two main factors judging effective incorporation in fluorometric applications. The planar photodiode excels in responsivity due to the device’s large active-area; however, high junction capacitance greatly hinders the response time. The lateral photodiode had much lower junction capacitance than the planar, but exhibited lesser responsivity due to the decreased active area size. The lateral photodiode was chosen as a candidate for timeresolved measurement due to the fast response of the device. Due to the responsiveness to low-light, the planar photodiode is chosen as the candidate for incorporation in fluorometric systems relying on irradiance measurement for operation