Portal de Periódicos da CAPES

Time-resolved electronic capture in n -type germanium doped with antimony

2014; American Physical Society; Volume: 89; Issue: 3 Linguagem: Inglês

10.1103/physrevb.89.035205

1550-235X

Н. Дессманн, S. G. Pavlov, V. N. Shastin, R. Kh. Zhukavin, V. V. Tsyplenkov, Stephan Winnerl, Martin Mittendorff, N. V. Abrosimov, H. Riemann, Heinz‐Wilhelm Hübers,

Advanced Chemical Physics Studies

The low temperature ($T$ = 5--40 K) capture of free electrons into hydrogenlike antimony centers in germanium has been studied by a time-resolving experiment using the free electron laser FELBE. The analysis of the pump-probe signal reveals a typical capture time of about 1.7 ns that decreases with pump energy to less than 1 ns while the number of ionized donors increases. The dependence on the pump-pulse energy is well described by an acoustic phonon-assisted capture process. In the cases when (i) a significant number of the electrons is in the conduction band (flux densities larger than 5 \ifmmode\times\else\texttimes\fi{} 10${}^{25}$ photons/(cm${}^{2}$ s), (ii) the lattice temperature is above \ensuremath{\sim}20 K, or (iii) a static electric field above \ensuremath{\sim}2 V/cm is applied to the crystal, the pump-probe technique reveals an additional intraband relaxation process with a characteristic time of \ensuremath{\sim}100 ps, which is much shorter than that of the capture of free electrons into the antimony ground state.