An explanation of the power-law decay of luminescence

Luminescence decay with time often shows a power-law dependence of the form intensity , where t is time and k is usually in the range 1–1.5. It is shown here that this power law can result from the tunnelling of trapped electrons to recombination centres that are randomly distributed, and that the range of exponents matches that of the observations. The explanation accounts for the most extreme case of an observed t−1.06 dependence extending over nine decades of time.