Photoluminescence lifetime distributions of amorphous and porous semiconductors, and organic luminescent materials; wideband quadrature frequency resolved spectroscopy extending over 11 decades

Here we present a newly developed wideband quadrature frequency resolved spectroscopy (QFRS) allowing analysis of photoluminescence (PL) lifetime over almost 11 decades (2 ns to 160 s). The system consists of dual phase double lock-in (DPDL) QFRS for lifetimes from ns to mus and internal mode QFRS for longer lifetime up to 160 s. The QFRS results of amorphous semiconductors exhibit the triple-peaked structures of lifetime distribution, well-known two peaks of which are attributed to singlet- and triplet-excitons, and the third and longest one, to distant-pair recombination being typical for amorphous materials. We also demonstrate double-peaked lifetime distributions of highly Ir(ppy)
₃
-doped organic films as well as rapidly oxidized porous silicon (PS)