Monday, December 12, 2016
Abstract-Terahertz detectors from Be-doped low-temperature grown InGaAs/InAlAs: Interplay of annealing and terahertz performance
The influence of post-growth annealing on the electrical properties, the transient carrier dynamics and the performance as THz photoconductive receiver of Beryllium (Be) InGaAs/InAlAs heterostructures grown at 130 °C in a system was investigated. We studied samples with nominally Be concentrations of 8 ×10 cm – 1.2 ×10 cm annealed for 15 min. – 120 min. at between 500 °C – 600 °C. In contrast to previous publications, the results show consistently that annealing increases the electron lifetime of the In analogy to the annealing of low-temperature grown (LTG) we explain our findings by the precipitation of arsenic antisite defects. The knowledge of the influence of annealing on the allowed for the fabrication of broadband THz photoconductive receivers with an electron lifetime below 300 fs and varying electrical properties. We found that the noise of the THz pulse trace in time-domain spectroscopy (TDS) was directly determined by the of the photoconductive receiver and the peak-to-peak amplitude of the THz pulse correlated with the electron mobility.