Crystal Size Dependence of Emission from Perylene Microcrystals

In this study, we found that, in perylene microcrystals, luminescence peak position from free-exciton state was gradually shifted to high energy side with reducing the crystal size, even if the microcrystals were fabricated by different kinds of preparation techniques. The life time of luminescence from self-trapped exciton state became shorter when the crystal size reduced. The main reason was estimated to be based on the change of lattice state.