I am working in the luminescence characterization of a coordination polymer (CP) in solid state. The CP contains only one type of ligand (organic molecule), which is reponsible for the luminescence emitted by the CP. I have measured the decay curves using multi-channel analyzer and the obtained curve shows a multi-exponential distribution. Two different components were necessary to correctly fit (tail fitting) the whole curve. Therefore, as I do not understand why a molecule could have those two different components, is it correct to give those two lifetimes or should I calculate the mean/average lifetimes?