Energy-transfer in CsPbBr3 nanocrystals: Sensitization of porphyrin triplets

Sensitizing molecular triplets by colloidal nanocrystals via triplet energy transfer is important for applications such as upconversion or organic synthesis. Typically two step triplet energy transfer (TET) are included in these applications: firstly the triplet energy stored in nanocrystals are extracted into surface ligands, and then the ligands further transfer triplet energy into molecules in bulk solution. Here we report one-step TET application from CsPbBr3 perovskite nanocrystals (NCs) to surface-anchored metalloporphyrin derivative molecules (MP). Compared to conventional two-step TET, the one-step TET mechanism possess lower energy loss and higher TET efficiency which is more generally implementable. In this scheme, photoexcitation of CsPbBr3 NCs leads to the sensitization of MP ligands triplets which efficiently emit phosphorescence. The enhanced light absorption of MP ligands and down-shifted photon emission can be useful in devices such as luminescent solar concentrators.