Pressure-induced two-color photoluminescence in MnF2 at room temperature

A novel two-color photoluminescence (PL) is found in MnF2 at room temperature under high pressure. Contrary to low-temperature PL, PL at room temperature is unusual in transition-metal concentrated materials like MnF2, since the deexcitation process at room temperature is fully governed by energy transfer to nonradiative centers. We show that room-temperature PL in MnF2 originates from two distinct Mn2+ emissions in the high-pressure cotunnite phase. The electronic structure and the excited-state dynamics are investigated by time-resolved emission and excitation spectroscopy at high pressure.