An advanced approach to control the electro-optical properties of LT-GaAs-based terahertz photoconductive antenna

• Published in: Materials research bulletin 2020-02, Vol.122, p.110688, Article 110688
• Main Authors: Buryakov, A.M., Ivanov, M.S., Nomoev, S.A., Khusyainov, D.I., Mishina, E.D., Khomchenko, V.A., Vasil’evskii, I.S., Vinichenko, A.N., Kozlovskii, K.I., Chistyakov, A.A., Paixão, J.A.
• Format: Article
• Language: English
• Subjects: Low temperature-grown gallium arsenide (LT-GaAs); Photoconductive antenna (PCA); Terahertz (THz) radiation; THz-antenna; THz-spectroscopy
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2019.110688

[Display omitted] •An approach for efficient modification of LT-GaAs films for PCA fabrication is described.•LT-GaAs films growth conditions underlying effective THz radiation are reported.•Spectral range of the developed antenna is up to 1 THz with a resonant maximum at 0.1 THz.•The antenna shows a 1.5- and 2-fold increase in THz power as compared to ZOMEGA and ZnTe.•The antenna attains a 3-fold increase in photocurrent efficiency as compared to ZOMEGA. This work reports on an advanced approach to the design of THz photoconductive. antenna (PCA). The LT-GaAs thin films used for the PCA fabrication were synthesized by MBE method on GaAs (100) substrate by adjusting the As pressure, As/Ga fluxes ratio, growth/annealing temperatures and annealing time. These parameters crucially affect electro-optical properties of the PCA samples as evidenced by the THz radiation power and time-domain spectroscopy measurements. The annealing temperature of 670 °C was found to be optimal for constructing a PCA possessing high amplitude of the THz radiation over the spectral range up to 1 THz at the resonance of 0.1 THz. The comparison of this PCA with the reference ZnTe crystal reveals a 2-fold increase in THz power. Furthermore, this antenna attains a 1.5-, 3-, and 2-fold increase in THz power, photocurrent efficiency, and actuating dc BV, as compared with the commercial ZOMEGA antenna. These results pave the way towards the creation of highly efficient LT-GaAs-based PCAs.