Abstract：
To investigate the effects of the pixel sizes and the electrode structures on the performance of Ge-based terahertz (THz) photoconductive detectors, vertical structure Ge:Ga detectors with different structure parameters were fabricated. The characteristics of the detectors were investigated at 4.2 K, including the spectral response, blackbody response (Rbb), dark current density-voltage characters, and noise equivalent power (NEP). The detector with the pixel radius of 400 μm and the top electrode of the ring structure showed the best performance. The spectral response band of this detector was about 20-180 μm. The Rbb of this detector reached as high as 0.92 A/W, and the NEP reached 5.4 × 10-13 W/Hz at 0.5 V. Compared with the detector with a pixel radius of 1000 μm and the top electrode of the spot structure, the Rbb increased nearly six times, and the NEP decreased nearly 12 times. This is due to the fact that the optimized parameters increased the equivalent electric field of the detector. This work provides a route for future research into large-scale array Ge-based THz detectors.
摘要：
研究像素尺寸和电极结构对Ge基太赫兹(THz)光电导探测器性能的影响,制备了具有不同结构参数的垂直结构Ge:Ga探测器。在4.2K下研究了探测器的特性，包括光谱响应，黑体反应（Rbb），暗电流密度-电压特性，和噪声等效功率（NEP）。像素半径为400μm的探测器和环形结构的顶部电极表现出最佳性能。该检测器的光谱响应带约为20-180μm。该探测器的Rbb高达0.92A/W，并且在0.5V时NEP达到5.4×10-13W/Hz。与像素半径为1000μm的探测器和点结构的顶部电极相比，Rbb增加了近六倍，NEP下降了近12倍。这是由于优化的参数增加了检测器的等效电场。这项工作为未来大规模阵列Ge基THz探测器的研究提供了途径。
