Effect of the environment on tris(2-phenylpyridine) iridium molecules embedded in a polyvinyl carbazole matrix

► We compare the emission from Ir(ppy)3 in PVK, CHCl3, PMMA, THF and CH2Cl2. ► The result suggests a higher zero-field splitting values for PVK environment. ► A thermal study is performed from 80 to 300 K. ► A lower effect of temperature on the population of substates I is observed. ► PVK matrix favours a resonant energy transfer to the substate I.