本论文针对高性能光纤通信和微波光子链路对光电探测器提出的新需求，开展了超高速光电探测器及其载流子输运机理研究。从载流子输运和等效电路模型两个方向对光电探测器中的饱和效应和速度过冲效应进行了理论研究。在此基础上，提出并实现了新型高性能光电探测器芯片。 在光电探测器的工作机理方面，首先通过蒙特卡洛仿真，分析了载流子在能量提升过程中受到的散射作用，获得了载流子速度过冲所需要的合适条件。其次，针对现有的等效电路模型未考虑光电流和电压的影响，无法有效分析光电探测器饱和效应与速度过冲效应的问题，建立了电流-电压相关的新型等效电路模型。我们在模型中增加基于外延结构的并联等效电容和电阻来拟合大电流情况下的S参数。利用新提出的等效电路模型成功分析了不同电压电流下光电探测器的性能，阐明了空间电荷效应对光电探测器饱和性能的影响，并进一步验证了电子速度过冲效应所需要的最佳条件。这对于超高速高饱和特性光电探测器的设计具有重要的指导意义。 在光电探测器的饱和特性方面，本论文设计并制作了电场增强型高饱和光电探测器。针对光电探测器吸收区和耗尽区能带不连续，易产生空间电荷效应的问题，我们通过在耗尽区插入掺杂层来增强导带不连续界面两侧的电场强度，制作了局部电场增强的高饱和宽带光电探测器，光电探测器饱和光电流从54 mA提高到99 mA。 在光电探测器的带宽性能方面，针对光电探测器带宽与饱和特性之间存在的矛盾以及大功率光电探测器带宽难以进一步提高的问题，我们通过在耗尽区中间插入一层薄p型InP，创新性地设计了双漂移层结构，既充分利用电子的速度过冲效应，又减小负载偏压摆幅效应的影响。制得的双漂移层光电探测器带宽达到106 GHz，输出光电流28 mA，为国际报道的同等条件下100 GHz以上光电探测器中最高水平。 综上所述，本论文从载流子的输运机理上对制约光电探测器性能提高的关键问题进行了研究，并成功制作了高性能的光电探测器芯片，相关性能指标达到国际领先水平，取得的成果为高性能半导体光电探测器的国产化奠定了基础。

In this dissertation, the ultra-high-speed photodetector and its carrier transport mechanism are studied for the new requirements of optical fiber communication and high performance microwave photonic link to detectors. From the carrier transport and the equivalent circuit model, the saturation effect and the velocity overshoot effect in the detector are studied theoretically. On this basis, new types of high performance photodetector chips are proposed and realized. In the aspect of the photodetector’s operation mechanism, firstly, the Monte Carlo simulation is used to analyze the carrier's scattering effect in the energy lifting process, and obtain the appropriate conditions which are necessary for the carrier velocity overshoot. Secondly, a new voltage- and photocurrent-dependent equivalent circuit model is established. By utilizing the existing equivalent circuit model which has not considering the influence of photocurrent and voltage, we can’t effectively analyze the saturation effect and velocity overshoot effect of the detector. We add parallel equivalent capacitance and resistance based on the epitaxial structure in the model to fit the S parameters with high photocurrent. The effect of space charge effect on the saturation performance of the detector is demonstrated by using the newly proposed equivalent circuit model. The best condition required for the electron velocity overshoot effect are further verified. This is of great significance for the design of ultrahigh speed and high saturation characteristic detectors. In the aspect of the saturation characteristics of the detector, an electric field enhanced high saturation detector is designed and fabricated in this paper. Aiming at the problem that the energy band between the absorption region and the depletion region are discontinuous and the space charge is easy to be accumulated, we increase the electric field intensity on both sides of the discontinuous interface of the conduction band by inserting a doped layer in the depletion region, and demonstrated a local electric field enhanced high saturation broadband detectors, the detector saturation photocurrent increases from 54mA to 99mA. In terms of the bandwidth performance of the detector, for the contradiction between the bandwidth and saturation characteristics of the detector, and the difficulty of further improving the bandwidth of the high power detector, we designed a dual-drifting layer structure by inserting a thin p-type InP layer into the middle of the depletion region, which makes full use of the velocity overshoot effect and reduces the influence of the load voltage swing effect. The dual-drifting layer detector has a bandwidth of 106GHz and the output photocurrent reaches up to 28mA, which is the highest level for 100 GHz detector with the same condition. In summary, this paper has studied the key problems of improving the performance of the detector from the carriers’ transport mechanism, and high performance detector chip has been successfully achieved. The related performance has reached the international leading level. The research achievements laid the foundation for the localization of high-performance semiconductor detectors.