title: Carbon irradiated semi insulating GaAs for photoconductive terahertz pulse detection.
abstract: 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.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Singh
authors.forename: Sanjoy
authors.initials: S
authors.lastname: Pal
authors.forename: Harshad
authors.initials: H
authors.lastname: Surdi
authors.forename: S S
authors.initials: SS
authors.lastname: Prabhu
authors.forename: S
authors.initials: S
authors.lastname: Mathimalar
authors.forename: Vandana
authors.initials: V
authors.lastname: Nanal
authors.forename: R G
authors.initials: RG
authors.lastname: Pillay
authors.forename: G H
authors.initials: GH
authors.lastname: Döhler