太赫兹量子阱探测器的暗电流抑制电路研究

摘要

The dark current suppression circuit and the equivalent circuit model of the terahertz quantum-well photode-tectors (QWPs)are introduced. The transport mechanisms of dark current and photocurrent are analyzed theoretical-ly. Because the transport model of terahertz QWPs is very complex,the analytical expression for the current-voltage relations used in the circuit model of terahertz QWPs cannot be obtained precisely. By fitting the experimental dark current-voltage and photocurrent-voltage data,the effective voltage controlled current source (VCCS)circuit model of terahertz QWPs is established. The effective circuit model is used to design the dark current suppression module and the signal source in readout circuit. The numerical simulation results show that the effective circuit model of terahertz QWPs works well. Compared with the traditional dark current suppression module,the VCCS circuit model can accu-rately suppress the dark current when the voltage of the terahertz QWPs changes. It’s more suitable for the dark cur-rent suppression module of the terahertz QWPs in the readout circuit.%主要研究了太赫兹量子阱探测器读出电路中的暗电流抑制模块。首先从理论上分析了太赫兹量子阱探测器产生暗电流和光电流的原理。由于太赫兹量子阱探测器中电子输运行为非常复杂，难以通过理论推导建立精确等效电路模型的解析表达式。通过对太赫兹量子阱探测器的电流电压实验数据进行拟合，提出压控电流源等效电路模型。利用此模型设计读出电路信号源及暗电流抑制模块，结合读出电路进行仿真验证电路模型的准确性。发现与传统暗电流抑制电路相比，压控电流源电路模型能够在器件工作偏压变化时对其暗电流进行精确抑制，提高读出电路性能，因此更适合作为太赫兹量子阱探测器读出电路的暗电流抑制模块。