Time-resolved photoluminescence of red mercuric iodide

1089-7550

AIP Digital Archive

Physics

Time-resolved photoluminescence (TRPL) spectrum of red mercuric iodide single crystal for two kinds of different grown methods was measured and compared at low temperatures. The different spectral structures were found for the different grown crystals. At the band-gap region two kinds of photoluminescence were similar. Sharp near band-gap luminescence due to the radiative annihilation of free and bound excitons was observed at 530 nm and a luminescent tail band that originated from the nonradiative annihilation of bound excitons appeared at 540 nm for two crystals. The 560 nm band was observed for the sublimation crystals and a broad luminescent band appeared at 630 nm for the acetone solution crystals, respectively. The TRPL experiment of the near band-gap lines revealed that luminescence comprised a fast and a slow decay component and showed several relaxation processes in free and bound exciton annihilation. The temporal behavior of the tail band revealed the same regularity for two kinds of crystals. The behavior was described with the rate equations and was obviously different from the band-gap luminescence. The 560 nm band had much slower decay than near band-gap decay. At the 630 nm band PL intensity was expressed as I(t)=t−n(r). The experiment of the red band showed clearly that the luminescence was ascribed to the radiative recombination of donor–acceptor pairs. © 2002 American Institute of Physics.

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