Highly Efficient Red/Near‐Infrared Phosphorescence from Doped Crystals

Organic red/near-infrared (NIR) room temperature phosphorescence (RTP) materials with low toxicity and facile synthesis are highly sought after, particularly for applications in biotechnology and encryption. However, achieving efficient red/NIR RTP emitters has been challenging due to the weak spin-orbit coupling of organics and the rapid nonradiative decay imposed by the energy gap law. Here we demonstrate highly efficient red/NIR RTP with boosted quantum yields (Φ