Designing and optimizing efficient organic room-temperature phosphorescent (RTP) materials remains a captivating yet challenging endeavour due to the inherent difficulties in generating and stabilizing triplet excitons. Here, we report a suite of highly efficient phosphors characterized by near-unity intersystem crossing (ISC) yields. Surprisingly, upon doping these dyes into a polyvinyl alcohol matrix, their phosphorescence quantum yields (Φ _P) spanned a wide range from 2.7% to 69.6%, governed by the position of the methyl substituent. Theoretical calculations and experimental results indicate that the variation in phosphorescence efficiency is primarily due to the strong electron-phonon coupling caused by the positional variation of the methyl substituents, rather than common factors such as ISC or energy levels. These findings provide a new insight into the design of high-performance organic RTP dyes.

This journal is © The Royal Society of Chemistry.

设计和优化高效的有机室温磷光（RTP）材料仍然是一个既吸引人又具有挑战性的课题，因为生成和稳定三重激发态（triplet excitons）存在内在的困难。在这里，我们报道了一系列高效磷光体，它们的特点是接近完美的系间窜跃（ISC）产率。令人惊讶的是，在聚乙烯醇基质中掺杂这些染料后，其磷光量子产率（Φ_P）范围广泛，从2.7%到69.6%，这取决于甲基取代基的位置。理论计算和实验结果表明，磷光效率的变化主要是由于甲基取代基位置变化所引起的强电子-声子耦合，而不是常见的因素如ISC或能级差异所致。这些发现为高效有机RTP染料的设计提供了新的见解。

本期刊属于英国皇家化学学会。