Nevinskas I, Mockus Z, Juškėnas R, Norkus R, Selskis A, Norkus E, Krotkus A. Terahertz Photoconductivity Spectra of Electrodeposited Thin Bi Films.
MATERIALS 2021;
14:ma14123150. [PMID:
34201229 PMCID:
PMC8230180 DOI:
10.3390/ma14123150]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/03/2021] [Accepted: 06/04/2021] [Indexed: 12/04/2022]
Abstract
Electron dynamics in the polycrystalline bismuth films were investigated by measuring emitted terahertz (THz) radiation pulses after their photoexcitation by tunable wavelength femtosecond duration optical pulses. Bi films were grown on metallic Au, Pt, and Ag substrates by the electrodeposition method with the Triton X-100 electrolyte additive, which allowed us to obtain more uniform films with consistent grain sizes on any substrate. It was shown that THz pulses are generated due to the spatial separation of photoexcited electrons and holes diffusing from the illuminated surface at different rates. The THz photoconductivity spectra analysis has led to a conclusion that the thermalization of more mobile carriers (electrons) is dominated by the carrier–carrier scattering rather than by their interaction with the lattice.
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