A Novel Double-Gate PIN Photodiode for Improving Switching Performance

In this manuscript, a novel double-gate PIN (DGPIN) photodiode has been proposed which exhibits faster changing of the photocurrent amplitude against changing of the light intensity. So, it can improve the slow switching operation of the ordinary PIN (OPIN) photodiode. In the proposed DGPIN, two metal-oxide-semiconductor (MOS) contacts (called the gates) on both sides of the intrinsic region have been considered. By biasing the gates, the potential barrier in the energy bands between the anode and cathode is decreased. So, the generated carriers can drift through the intrinsic region faster and the recovery time is reduced. Also, it has been shown that the forward and reverse trajectories in the photocurrent-light intensity curve (formed by increasing and decreasing of the illuminating light intensity, respectively) are closer in the DGPIN which indicates more linear current–light behavior for the DGPIN than the OPIN. For evaluating the linearity of the current–light behavior, the corresponding curves have been simply modeled by fitting ellipses. For the fitting ellipses, closer eccentricity to 1 indicates more linear current–light behavior and larger rotation angle indicates smaller recovery time of the device. By using this simple model, the effects of changing the physical and geometrical parameters of the proposed DGPIN on its linear operation and recovery time have been investigated.