Enhanced terahertz radiation of photoconductive antenna fabricated on GaAs-on-sapphire

Jitao Zhang, Mingguang Tuo, Michael Gehl, Ricky Gibson, Min Liang, Hao Xin

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


The terahertz (THz) radiation properties of a photoconductive antenna (PCA) fabricated on a GaAs-on-sapphire (GoS) substrate are reported at sub-THz band. The GaAs layer with a thickness of approximately 1 μm was directly deposited on a sapphire wafer by means of molecular beam epitaxy. A butterfly-shaped antenna structure was then fabricated on the GoS substrate by photolithography, and the device was tested as the emitter of an in-house built THz time-domain spectrometer. The performance of this antenna was compared with a commercial one, which had an identical antenna structure but was fabricated on low-temperature-grown GaAs (LT-GaAs). The results showed that the GoS-based PCA radiated an enhanced THz field, which could be as much as 1.9 times that of the LT-GaAs-based PCA, indicating that GoS could be a promising photoconductive material. In addition, the optical transparency of the sapphire substrate allows the device to be illuminated from the backside, which is crucial for THz near-field imaging applications where the sample is usually in close proximity to the front surface of the PCA device.

Original languageEnglish (US)
Article number125234
JournalAIP Advances
Issue number12
StatePublished - Dec 1 2019

ASJC Scopus subject areas

  • General Physics and Astronomy


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