Low-temperature time-resolved spectroscopy of APb2X5 crystals (A K, Rb; X Cl, Br)

The paper reports on a low-temperature (8 K) time-resolved spectroscopic study of excitonic states and radiative relaxation of electronic excitations in undoped APb(2)X(5) crystals (A K, Rb; X Cl, Br) performed under selective photoexcitation by synchrotron radiation. The study has revealed a variety of channels of radiative relaxation of intrinsic electronic excitations, which should be primarily assigned to specific features of the electronic structure of the crystal.