Fig. 2: Photophysical properties of [PXZDBFDP]2Cu4I4 and [PhPXZDBFDP]2Cu4I4.
From: Excited state reversal in copper iodide clusters enables 100% exciton radiation
![Fig. 2: Photophysical properties of [PXZDBFDP]2Cu4I4 and [PhPXZDBFDP]2Cu4I4.](http://media.springernature.com/full/springer-static/image/art%3A10.1038%2Fs41467-025-67664-x/MediaObjects/41467_2025_67664_Fig2_HTML.png?as=webp)
a Electronic absorption (abs., upper left) of [PXZDBFDP]2Cu4I4 and [PhPXZDBFDP]2Cu4I4 in dilute dichloromethane solution (10-6 mol L-1) and excitation (exc., below left) and photoluminescence (PL) spectra (right) of BCPO:x% [PXZDBFDP]2Cu4I4 and [PhPXZDBFDP]2Cu4I4 films (x = 100 for neat cluster films, and x = 20). BCPO is bis-4-(N-carbazolyl)phenyl)phenylphosphine oxide used as host matrix. MLCT refers to metal-ligand charge transfer. Prompt (PF) and delayed fluorescence (DF) and phosphorescence (PH) spectra at x = 20 were measured with time-resolved technology in the ranges of < 1 µs, 1–100 µs and > 200 µs, respectively. PL spectrum of neat [PhPXZDBFDP]2Cu4I4 film is fitted with dual peaks corresponding to MLCT and CC transitions, respectively highlighted with green and red fill colors; b Time decays (left) of BCPO:x% [PXZDBFDP]2Cu4I4 and [PhPXZDBFDP]2Cu4I4 films and dependence of PL quantum yields (PLQY) on doping concentrations of the films; c Temperature dependence of average lifetimes for [PXZDBFDP]2Cu4I4 and [PhPXZDBFDP]2Cu4I4 based films (left) and temperature-dependent fractional contributions of thermally activated delayed fluorescence (TADF) and PH to total emissions of [PXZDBFDP]2Cu4I4 based films (right); d Temperature-dependent time-resolved emission spectra (TRES) of BCPO:20% [PXZDBFDP]2Cu4I4 and [PhPXZDBFDP]2Cu4I4 films at 50 and 300 K.
