Time-resolved photoluminescence is used to determine carrier recombination through radiative and nonradiative processes in zinc hydroxide Zn(OH)(2) and its porous composites with graphite oxide (GO). The decay times, measured by a streak camera, are found to be larger for zinc hydroxide (~1215±156 ps) than its composites (~976±81 ps for ZnGO-2 and 742±59 ps for ZnGO-5), but no significant changes in rise times (from 4.0 to 5.0 ps) are recorded. The dominant mechanism for the radiative process is attributed to free carrier recombination, while microporous networks present in these materials are found to be pathways for the nonradiative recombination process via multiphonon emission.
4 Figures and Tables
Table 1. Lifetime (τ0), Rise Time (τ1), and Fluorescence Decay Rate Constant (k) of Zn OH 2, ZnGO-2, and ZnGO-5 Provided Best Fit to Fluorescence (TRPL) Profiles
Fig. 2. TRPL spectra of Zn OH 2, ZnGO-2, and ZnGO-5 are shown together in (a), and Zn OH 2, ZnGO-2, and ZnGO-5 are shown separately in (b)–(d).
Fig. 3. TPF images show light-emitting regions (i.e., aggregates of particles) and distribution of pores (i.e., white areas) of many sizes in Zn OH 2, ZnGO-2, and ZnGO-5, and pathways of light traveling and trapping.
Fig. 4. Fluorescence intensity profiles for different values of fluorescent decay rate constant (k).
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