Enhancement of hot-carrier photoluminescence with intense terahertz pulses

摘要

Intense terahertz (THz) pulses have been shown to induce photoluminescence (PL) quenching in bulk semiconductors. We show that in addition to PL quenching near the bandgap, intense THz pulses enhance the high-energy tail of the PL in GaAs. Furthermore, we propose a simple model that accounts for both PL quenching and enhancement where THz-induced hot carriers directly enhance high-energy PL but reduce overall radiative efficiency due to ultrafast diffusion. Exploring the interplay between THz-induced PL enhancement and quenching over a range of excitation parameters reveals a reduction of integrated PL at low photoexcitation fluence, while at higher fluences, the amplitude of the PL quenching is balanced by that of the PL enhancement. Published by AIP Publishing.