室温中波红外碲镉汞探测器激光辐照饱和特性的仿真

Simulation on the saturation properties of room-temperature midwave infrared HgCdTe detectors

针对室温工作的光伏型碲镉汞中波红外探测器激光辐照饱和特性进行了仿真,结果表明,中红外激光对碲镉汞材料的加热效应以及光照导致零偏压阻抗降低,是影响探测器输出量子效率的重要因素。利用一维数值仿真方法,建立了室温碲镉汞pn结的模型,计算了稳态激光辐照下器件量子效率以及零偏压阻抗。理论计算了激光辐照下的稳态温度分布近似模型,并将温度场分布耦合到仿真计算中,发现衬底厚度会影响芯片的温升,从而显著影响器件饱和阈值的大小。另外,计算表明,随着光照强度的增加,器件的零偏压阻抗降低,并将仿真结果与实测芯片参数进行了比较。计算分析为设计高饱和辐照度阈值的中波红外碲镉汞探测器提供了参考。

The photovoltaic mid-wave infrared HgCdTe detector,which is operated at room temperature,is simulated to explore laser irradiation saturation characteristics.The results reveal that the heating effect on the HgCdTe material and the lowering of the zero-bias impedance due to irradiation,are significant factors affecting the quantum efficiency of the detector.The model of HgCdTe pn junction is established,and a one-dimensional numerical simulation method is adopted to compute the quantum efficiency and zero-bias impedance of device.The device is irradiated under steadystate.Moreover,the temperature field distribution is coupled in the simulation,the thickness of substrate affects the temperature of the detector,which significantly affects the saturation threshold of the device.Furthermore,the calculations show that the zero-bias impedance of device decreases when the light intensity is raised.The result is compared to the measured performance of device.Finally,the computational analysis serves as a foundation for the development of mid-wave IR HgCdTe detectors with high saturation irradiance threshold.