Raising Near-Infrared Photoluminescence Quantum Yield of Au<sub>42</sub> Quantum Rod to 50% in Solutions and 75% in Films
Lianshun Luo, Zhongyu Liu, Abhrojyoti Mazumder, Rongchao Jin
Abstract
High Resolution Image Download MS PowerPoint Slide Highly emissive gold nanoclusters (NCs) in the near-infrared (NIR) region are of wide interest, but challenges arise from the excessive nonradiative dissipation. Here, we demonstrate an effective suppression of the motions of surface motifs on the Au 42 (PET) 32 rod (PET = 2-phenylethanethiolate) by noncoordinative interactions with amide molecules and accordingly raise the NIR emission (875/1045 nm peaks) quantum yield (QY) from 18% to 50% in deaerated solution at room temperature, which is rare in Au NCs. Cryogenic photoluminescence measurements indicate that amide molecules effectively suppress the vibrations associated with the Au–S staple motifs on Au 42 and also enhance the radiative relaxation, both of which lead to stronger emission. When Au 42 NCs are embedded in a polystyrene film containing amide molecules, the PLQY is further boosted to 75%. This research not only produces a highly emissive material but also provides crucial insights for the rational design of NIR emitters and advances the potential of atomically precise Au NCs for diverse applications.