The NPN InP/InGaAs heterojunction phototransistor (HPT) is numerically simulated with a two dimensional model based on a finite difference method. The electrical and optical characteristics of HPT are analyzed with different base thickness and compared as the base was scaled from 60 down to 20 nm. The impact of the base thickness on the photocurrent is highlighted and compared with the dark and the photodiode currents. This paper also includes the effect of optical power and base current on the potential, electrons density and energy band diagrams. The results show that responsivity and optical gain are not only strongly dependent on the base thickness but also on the base current. The increasing of the current gain from 60 to 100 as the base was scaled from 60 down to 20 nm. Responsivity of 14.7 A/W for 1100 nm light is achieved when the thickness of base layer is 20 nm. A good qualitative agreement of the numerical and analytical simulated value of responsivity as a function of the wavelength with the existing experimental data was achieved.

NPN InP/InGaAs 异质结光电晶体管 (HPT) 使用基于有限差分方法的二维模型进行数值模拟。对不同基底厚度的 HPT 的电学和光学特性进行了分析，并在将基底从 60 缩小到 20 nm 时进行比较。突出显示基极厚度对光电流的影响，并与暗电流和光电二极管电流进行比较。本文还包括光功率和基电流对电位、电子密度和能带图的影响。结果表明，响应度和光学增益不仅强烈依赖于基极厚度，而且还依赖于基极电流。随着基数从 60 缩小到 20 nm，电流增益从 60 增加到 100。14. 响应率 当基层的厚度为 20 nm 时，1100 nm 的光达到 7 A/W。作为波长的函数的响应度的数值和分析模拟值与现有实验数据具有良好的定性一致性。