Are there materials or molecules where fast internal conversion is desirable?

For light-emitting devices fast internal conversion is typically considered as a downside as it competes with fluorescence and phosphorescence. A low internal conversion rate is thus typically desired for molecules in applications in light emitting devices, like OLED's, and molecules with high photoluminescence quantum yield are searched for.


I am wondering if there are materials or applications, where the opposite is the case. I.e. where one looks for molecules with fast internal conversion. Are there properties/materials that benefit from fast internal conversion of a molecule?


