Here, N and Z denote the number of states and partition functions, respectively, for the electron and hole components, and v is a thermal emission fitting factor. The probability of an electron or hole undergoing internal conversion here is proportional to the energy difference between its energy and that of the wetting layer (activation energy). The thermal fitting factor can be considered in terms of how the activation energy is affected by the dominant form of loss in the quantum system . The damping factor of v can be used to differentiate between the different forms of thermal emission that tells which sort of thermal escape you have ; scaling of v when compared to experiment can allow for the distinction between excitonic, uncorrelated pairs, or single charge carrier losses.