Quantifying the Ligand-Induced Triplet Energy Transfer Barrier in a Quantum Dot-Based Upconversion System

• DOI: 10.1021/acs.jpclett.2c00514
• Publication Date: 2022-03-29T12:04:47Z
• Authors: Tsumugi Miyashita; Paulina Jaimes; Tianquan Lian; Ming Lee Tang; Zihao Xu
• Keywords: Photon Upconversion; Quantum yield

During photon upconversion, quantum dots (QDs) transfer energy to molecules in solution through a long ligand shell. This insulating shell imparts colloidal stability at the expense of efficient photosensitization. For first time, we quantify barrier these aliphatic ligands pose for triplet solution. Using transient absorption spectroscopy, experimentally measure small damping coefficient 0.027 Å-1 exceeding 10 carbons length. The dynamic nature lowers charge or compared organic thin films. In addition, show that surface shorter than 8 length allow direct from QD, bypassing need transmitter mediate transfer, leading 6.9% upconversion yield with 0.01% 18 carbons. derived insight will enable design QD-based photosensitizers catalysis and conversion.