Abstract
Luminescence properties of hydrogen-bonded ferroelectrics PbHPO 4 (LHP) have been studied in the temperature range of 10 to 320 K. A broad luminescence band with a large Stokes shift is observed at 2.8 eV, stimulated efficiently at the first exciton band region. This result strongly suggests that the luminescence band is intrinsic in origin and it is due to annihilation of self-trapped excitons. This is in agreement with the small value of the steepness parameter ( 0 =0.78) of the Urbach tail. The time-resolved photoluminescence measurement indicates that the 2.8 eV luminescence consists of composite bands which decay with lifetimes of 6 ns, 600 ns and 60 s.