Singh Abhishek, Pal Sanjoy, Surdi Harshad, Prabhu S S, Mathimalar S, Nanal Vandana, Pillay R G, Döhler G H
Opt Express. 2015 Mar 9;23(5):6656-61. doi: 10.1364/OE.23.006656.
We report here a photoconductive material for THz detection with sub-picosecond carrier lifetime made by C(12) (Carbon) irradiation on commercially available semi-insulating (SI) GaAs. We are able to reduce the carrier lifetime of SI-GaAs down to sub-picosecond by irradiating it with various irradiation dosages of Carbon (C(12)) ions. With an increase of the irradiation dose from ~10(12) /cm(2) to ~10(15) /cm(2) the carrier lifetime of SI-GaAs monotonously decreases to 0.55 picosecond, whereas that of usual non-irradiated SI-GaAs is ~70 picosecond. This decreased carrier lifetime has resulted in a strong improvement in THz pulse detection compared with normal SI-GaAs. Improvement in signal to noise ratio as well as in detection bandwidth is observed. Carbon irradiated SI-GaAs appears to be an economical alternative to low temperature grown GaAs for fabrication of THz devices.
我们在此报告一种用于太赫兹（THz）检测的光导材料，其通过对市售半绝缘（SI）砷化镓进行碳（C¹²）辐照制成，具有亚皮秒级的载流子寿命。通过用不同辐照剂量的碳（C¹²）离子辐照，我们能够将SI - 砷化镓的载流子寿命降低至亚皮秒级。随着辐照剂量从约10¹² /cm²增加到约10¹⁵ /cm²，SI - 砷化镓的载流子寿命单调下降至0.55皮秒，而通常未辐照的SI - 砷化镓的载流子寿命约为70皮秒。与普通SI - 砷化镓相比，这种降低的载流子寿命使得太赫兹脉冲检测有了显著改善。观察到信噪比以及检测带宽都有所提高。碳辐照的SI - 砷化镓似乎是用于制造太赫兹器件的低温生长砷化镓的一种经济替代品。
