Details

Autor(en) / Beteiligte

• Molis, G.
• Adomavičius, R.
• Krotkus, A.

Titel

Temperature-dependent terahertz radiation from the surfaces of narrow-gap semiconductors illuminated by femtosecond laser pulses

Ist Teil von

• Physica. B, Condensed matter, 2008-10, Vol.403 (19), p.3786-3788

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2008

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Temperature-dependent increase of the terahertz (THz) electric field emitted from the surfaces of optically pumped narrow-gap semiconductors InAs, InSb, and Cd x Hg 1− x Te is presented. In the case of Cd 0.2Hg 0.8Te increase up to 15–17 times has been observed, when cooling the sample from the room temperature to close to liquid-helium temperatures, and THz emission from this material becomes comparable to that of p-InAs emitter. This effect was explained in terms of the increased photoexcited electron excess energy due to the positive temperature coefficient for energy bandgap of Cd x Hg 1− x Te, as well as by weaker surface field screening and carrier–carrier scattering. Temperature-dependent modification of the shape of THz pulses emitted from InSb surfaces has been observed and attributed to plasma oscillation of the cold electrons.