Based On The Black Silicon/porous Silicon Pin Photodetector Simulation Research

Due to the limitation of silicon itself, the Si based photodetector impossible to be used, either as the light receiving device which can detect the light at wavelength of1.3μm or1.55μm in civil communication systems, or as the core component in the infrared-guided or laser warning systems in military usage. Thus, it is needed to develop a novel new silicon photodetector which has a higher responsivity and an extended spectral response range.This thesis made full use of the so called microstructured surface features and the doping effects of black silicon and/or porous silicon, and carried out a simulation study of the novel Si-PIN photodetector made of black/porous silicon based on theoretical calculation. By using the simulation software named Silvaco TCAD, we studied the performances such as spectral response, quantum efficiency, light responsivity, Ⅰ-Ⅴ characteristics, dark current and response time, respectively. Finally, the simulation results could provide a guidance for the actual processing of the new photodetectors.The simulation results of the PIN photodetector based on porous silicon without impurity energy show:(1) that the quantum efficiency and responsivity of the front illuminated detector at peak wavelength of0.9μm are93.19%and0.67A/W. Compared with the conventional photodetector, the quantum efficiency and responsivity are increased by31.32%and0.22A/W. But the quantum efficiency and responsivity of the front illuminated detector at1.05μm are13.27%and0.09A/W, which are the same as those of conventional photodetectors.(2) that the dark current and response time of the front illuminated detector are1.5×10-12A and2×10-6s, which are also the same as those of conventional photodetectors.(3) that the quantum efficiency and responsivity of the back illuminated detector at peak wavelength of0.95μm are64.87%and0.49A/W. But the quantum efficiency and responsivity of the back illuminated detector at1.05μm are13.09%and0.11A/W, the dark current and response time of the back illuminated detector are6.5×10-6A and8×10-6s, all of which are the same as those of conventional photodetectors.The simulation results of the PIN photodetector based on black silicon with impurity energy show:(1) that the quantum efficiency and responsivity of the front illuminated detector at peak wavelength of0.9μm are94.39%and0.69A/W. Compared with the conventional photodetector, the quantum efficiency and responsivity are increased by32.52%and0.24A/W at the rate of53.33%. Also, the quantum efficiency and responsivity of the front illuminated detector at1.05μm are33.35%and0.28A/W, increased by21.73%and0.17A/W at the rate of170%, compared with the conventional photodetector.(2) that the dark current and response time of the front illuminated detector are1.0×10-11A and1.2×10-6s, which are the same as those of conventional photodetectors.The results show that while keeping the dark current and respose time at a center level, the novel Si-PIN photodetector made of black/porous silicon really can not only increase both the detector’s quantum efficiency and responsivity by a relatively large rate, but also can extended the spectral response range properly.