Switching on near-infrared light in lanthanide-doped CsPbCl3 perovskite nanocrystals

Abstract

The accessible emission spectral range of lead halide perovskite (LHP) CsPbX₃ (X = Cl, Br, I) nanocrystals (NCs) has remained so far limited to wavelengths below 1 μm, corresponding to the emission line of Yb³⁺, whereas the direct sensitization of other near-infrared (NIR) emitting lanthanide ions is unviable. Herein, we present a general strategy to enable intense NIR emission from Er³⁺ at ∼1.5 μm, Ho³⁺ at ∼1.0 μm and Nd³⁺ at ∼1.06 μm through a Mn²⁺-mediated energy-transfer pathway. Steady-state and time-resolved photoluminescence studies show that energy-transfer efficiencies of about 39%, 35% and 70% from Mn²⁺ to Er³⁺, Ho³⁺ and Nd³⁺ are obtained, leading to photoluminescence quantum yields of ∼0.8%, ∼0.7% and ∼3%, respectively. This work provides guidance on constructing energy-transfer pathways in semiconductors and opens new perspectives for the development of lanthanide-functionalized LHPs as promising materials for optoelectronic devices operating in the NIR region.