Title :
Fast relaxation of free carriers in compensated n- and p-type germanium
Author :
Dessmann, N. ; Pavlov, S.G. ; Mittendorff, M. ; Winnerl, S. ; Zhukavin, R.Kh. ; Tsyplenkov, V.V. ; Shengurov, D.V. ; Shastin, V.N. ; Abrosimov, N.V. ; Riemann, Heike ; Hubers, Heinz-Wilhelm
Author_Institution :
Inst. fur Opt. und Atomare Phys., Tech. Univ. Berlin, Berlin, Germany
Abstract :
The relaxation of free holes and electrons in highly compensated germanium doped by gallium (p-Ge:Ga:Sb) and antimony (n-Ge:Sb:Ga) has been studied by a pump-probe experiment with the free-electron laser FELBE at the Helmholtz-Zentrum Dresden-Rossendorf. The relaxation times vary between 20 ps and 300 ps and depend on the incident THz intensity and compensation level. The relaxation times are about five times shorter than previously obtained for uncompensated n-Ge:Sb and p-Ge:Ga. The results support the development of fast photoconductive detectors in the THz frequency range.
Keywords :
antimony; carrier relaxation time; elemental semiconductors; free electron lasers; gallium; germanium; photodetectors; FELBE; Ge:Sb,Ga; Helmholtz-Zentrum Dresden-Rossendorf; THz frequency range; compensated n-type germanium; compensation level; fast photoconductive detectors; free carriers; free holes; free-electron laser; incident THz intensity; p-type germanium; pump-probe experiment; relaxation times; time 20 ps to 300 ps; Crystals; Detectors; Free electron lasers; Germanium; Impurities; Laser excitation; Probes;
Conference_Titel :
Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), 2013 38th International Conference on
Conference_Location :
Mainz
DOI :
10.1109/IRMMW-THz.2013.6665867
