 Triplet-triplet annihilation

Triplet-triplet annihilation (TTA) is a photophysical process that occurs in molecular systems, particularly those involving organic molecules or organic semiconductors. This phenomenon involves the interaction of two triplet excited states, leading to a variety of interesting outcomes, typically in the context of energy transfer and photon generation. ### Key Concepts: 1. **Triplet States**: Molecules can be excited to higher energy levels upon absorption of photons.