Ultrafast dynamics of hot carriers in bulk semiconductors and in accumulation layer: energy relaxation and screening effects.

The rapid development of the computational methods based on density functional theory, on the one hand, and of the time- energy- and momentum- resolved spectroscopy, on the other hand, allows today an unprecedently detailed insight into the processes governing hot electron relaxation dynamics, and into the role of the electron-phonon coupling. Recently, we have demonstrated, for the relaxation of hot carriers in GaAs, the existence of two distinct relaxation regimes, one related with the momentum, and the other with energy relaxation. In this work, we will present our new results, both experimental and theoretical, on hot electron relaxation in silicon. Numerous additional experiments were performed with respect to previous work, and a new interpretation of the measured relaxation times is provided [1]. Moreover, we will present our recent results on the hot electron relaxation in InSe. InSe is a quasi-2D material which was shown recently to have potential interest for optoelectronics [2]. In this work, we will discuss our new results on the relaxation and cooling dynamics in doped InSe.
[1] Tanimura et al, Phys. Rev. B 100, 035201 (2019).
[2] Chen et al, Phys. Rev. B 97, 241201(R) (2018).