Intraband inversion in semiconductors with ultrashort carrier lifetimes
The authors studied the lifetimes and the luminescence spectra of photoexcited carriers in H+-bombarded InP for different damage doses by means of femtosecond luminescence spectroscopy. The lifetime decreases down to 95 fs for a dose of 1016 cm-2 and the time-integrated luminescence spectrum of this sample is inverted. Taking into account the different thermalization and relaxation conditions for electrons and holes, they find that the time-averaged hole distribution is hot but thermalized, whereas the time-averaged electron distribution is inverted, meaning that the electron distribution function increases with increasing energy within the conduction band.