A. V. Andrianov, E. I. Terukov, A. N. Aleshin, S. N. Abolmasov, “Manifestation of the electric field screening effect in the process of generation of terahertz radiation in $p$–$n$-heterostructures $a$-Si:H/$a$-SiC:H/$c$-Si at photoexcitation by ultrashort laser pulses”, Pisma v Zhurnal Tekhnicheskoi Fiziki, 2025, Volume 51, Issue 10,Pages 22

Manifestation of the electric field screening effect in the process of generation of terahertz radiation in $p$–$n$-heterostructures $a$-Si:H/$a$-SiC:H/$c$-Si at photoexcitation by ultrashort laser pulses

A. V. Andrianov^a, E. I. Terukov^abc, A. N. Aleshin^a, S. N. Abolmasov^ac

^a Ioffe Institute, St. Petersburg
^b Saint Petersburg Electrotechnical University "LETI"
^c R&D Center TFTE, St.-Petersburg

Abstract: Data are presented on the manifestation of the strong influence of the electric field screening effect in $p$–$n$-heterostructures $a$-Si:H/$a$-SiC:H/$c$-Si on the properties of generated THz radiation in such structures under conditions of interband photoexcitation by femtosecond laser pulses. Screening of the field in the structure by nonequilibrium charge carriers at high pump intensity leads to a change in the direction of the electric field of the generated THz electromagnetic wave, which manifests itself as a change in the polarity of the pulse of the detected THz signal. The change in signal polarity can be associated with a change in the direction of the fast component of the photocurrent in the structure responsible for THz generation. A change in the polarity of the THz radiation pulse is observed both with a change in the photoexcitation intensity and with a change in the bias voltage.

Keywords: terahertz electromagnetic radiation, heterostructures, femtosecond laser excitation, fast photocurrent.

Received: 20.12.2024
Revised: 31.01.2025
Accepted: 31.01.2025

DOI: 10.61011/PJTF.2025.10.60327.20232