محيا نصيري فيجوني

In this thesis, a comprehensive study has been done on the most important parameters of single photon avalanche diode SPAD and silicon photomultiplier (SiPM) in medical applications and these parameters such as average source power, pulse repetition rate, full width at half maximum value (FWHM), light wavelength, dark count rate (DCR), photon detection efficiency (PDE) and... have been collected for light sources and detectors used in near infrared spectroscopy (NIRS) and then in two different wave groups It is categorized as continuous (CW) and time domain (TD). The ultimate goal is to reach a compromise between the various parameters of the detector according to the application. In the thesis, it is focused on a new modeling for DCR using non-local ionization coefficients. Until now, all the models presented to calculate the probability of avalanches assumed the local electric field. As a result, in high electric fields, the local model predicted the ionization distance very small, and the probability of avalanche occurrence was not accurately calculated. The new non-local model is based on considering a non-local dependence of impact ionization on the electric field, and it is possible to calculate the probability of avalanche occurrence and then DCR using this new model. This model has been eva‎luated on two SPADs simulated in standard 0.15 and 0.18 μm CMOS SPAD processes, then the results obtained with the local model and the data obtained from the experiment have been compared, which at higher bias voltages, the non-local model It approaches the experimental data by 25%. In the end, for a more accurate simulation, the non-local band model has been used. The results show that the DCR calculated by modeling the ionization coefficients and band-to-band tunneling is almost consistent with the experimental results.

ديود بهمن تك فوتون , مدل سازي غيرمحلي , نرخ شمارش تاريك , طيف سنجي مادون قرمز

Single Photon Avalanche Diode , Non Local Modeling , Dark Count Rate , Near Infrared Spectroscopy

Mahya Nasiri

Dr. Mohammad Azim Karami