Luminescence spectroscopy of V3+-doped Cs2NaYCl6 under high pressure

The luminescence behavior of 1% V3+:Cs2NaYCl6 at room temperature is studied as a function of hydrostatic pressure. At ambient pressure the V3+ 3T2g excited state origin lies 234 cm−1 above the 1T2g first excited state. At room temperature the two states are in thermal equilibrium, and spin-allowed 3T2g→3T1g emission is dominant. Pressure increases the energetic separation of 1T2g and 3T2g, leading to a decreasing 3T2g steady state population at constant temperature. This manifests itself in an increasing relative amount of spin-forbidden 1T2g→3T2g luminescence, as evidenced by the occurrence of sharp luminescence features and an increase in the luminescence decay time at higher pressures.