Carbon irradiated semi insulating GaAs for photoconductive terahertz pulse detection |
Optics Express, Vol. 23, Issue 5, pp. 6656-6661 (2015)
http://dx.doi.org/10.1364/OE.23.006656
http://dx.doi.org/10.1364/OE.23.006656
We report here a photoconductive material for THz detection with sub-picosecond carrier lifetime made by C12 (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 (C12) ions. With an increase of the irradiation dose from ~1012 /cm2 to ~1015 /cm2 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.
© 2015 Optical Society of America
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