一种改进型金属-半导体-金属光电探测器数学模型

以E. Sano的金属-半导体-金属光电探测器(MSM-PD)模型为基础,提出了一种改进型的模型。该模型以多个电流源和电容并联的形式构造,以吸收区过剩电子和空穴总数为研究对象,求解速率方程。另外计算了电容,给出了暗电流与端电压的非线性计算式,改进了传统模型中暗电流的线性计算方法。通过线性叠加给出了该模型光电流的数学解析解。通过在Matlab中的模拟计算,表明该模型具有计算量小、准确度高的特点,它不仅能反映一定偏压和光照下光电流的变化,而且能展示光电子在器件中的转化过程。这种模型也能较好地应用于微弱信号的检

Based on E. Sano′s metal-semiconductor-metal photodetector (MSM-PD) model, an improved numerical model is presented. The model is built with parallel current sources and capacitance. The sum of excess electron and photon in absorption layer is studied, and the rate equations are solved. The capacitance is calculated, the nonlinear relationship between the dark current and the terminal voltage is derived, and the linear calculation of the dark current in conventional model is improved. The mathematical expression of the photoelectric current is presented. The simulation analysis by Matlab indicates the calculation is simplified with a higher precision. This model represents the change of photoelectric current under some bias and illumination conditions, and shows the transfer of photoelectron in devices. This model can also be used in measuring and simulating weak signals.