Temperature dependence of terahertz radiation from n-type InSb and n-type InAs surfaces

Temperature dependence of terahertz emission from InMnAs

“…This work builds on the large body of literature related to terahertz emission from InAs. [5][6][7]11,13,20,21 We have observed a temperature-induced polarity reversal of the terahertz radiation from both p-InMnAs and n-InMnAs, in contrast to what has been previously observed in p-InAs. 6,7 We attribute the observed polarity reversal of the terahertz radiation to the competition between two oppositely directed sources of photoinduced current: the surface-fieldinduced current and the photo-Dember effect.…”

“…Many studies have examined terahertz emission from a variety of III-V semiconductors surface, including InAs, InSb, InP, and GaAs. [5][6][7][8][9][10][11] In particular, magnetic-field-induced enhancement of terahertz radiation from nonmagnetic semiconductor surfaces has been investigated thoroughly. [11][12][13][14][15][16] Recently, terahertz emission from ferromagnetic metal films 17,18 and from the dilute ferromagnetic semiconductor GaMnAs ͑Ref.…”

Monte Carlo Simulation of Dember Effect in n-InAs under Subpicosecond Laser Pulse Excitation

“…Recently generation of terahertz (THz) electromagnetic radiation from semiconductor surface excited by femtosecond laser pulses has been widely studied [1][2][3][4]. It has been established that this effect is caused by the pulse of photocurrent arising from ultra-fast redistribution of photoexcited carriers in semiconductor subsurface region.…”

“…For example, in n-GaAs the contribution of diffusion component in photo-emf is insignificant, and the barrier mechanism caused by the spatial redistribution of electrons and holes under the surface depletion field is dominant. However, for narrow-gap semiconductors, such as n-InAs and n-InSb, the main contribution * e-mail: vitaly@optoinform.bas-net.by (169) to the generation of THz pulses is due to the photo-Dember effect caused by the diffusion separation of photoexcited electrons and holes [4][5][6][7].…”

“…However, for n-InAs irradiated by the laser pulse at a wavelength of 800 nm, photoexcited electrons for a time of about 1-2 ps after photoexcitation have a large kinetic energy and are capable to diffuse more effectively than the thermal carriers. In this case the diffusion photovoltage can reach the value far beyond the stationary photo-emf, and as a result the photo-Dember effect can be mainly responsible for THz-pulse generation in n-InAs [4][5][6][7].…”