Flexible Room-Temperature Phosphorescent Materials With Matrix-Independent Luminescence Enabled by Host-Guest Encapsulation.

Abstract

Flexible room-temperature phosphorescence (RTP) materials hold great promise for a wide range of optical applications. However, the strong interdependence between luminescent and mechanical properties severely hampers further advances in this field. Herein, we report a γ-cyclodextrin (γ-CD)-based host-guest encapsulation strategy to address this challenge. The intrinsic cavity of γ-CD stabilizes triplet excitons to afford robust phosphorescence emission, while compositional regulation enables broad tuning of the mechanical properties, thereby achieving effective decoupling of these two properties and endowing the system with matrix-independent phosphorescence. The mechanical properties can be tailored across a wide range, with a tensile strength of 4.0-30.7 MPa, elongation at break of 402%-1501%, modulus of 1.6-280.1 MPa, and toughness of 11.1-193.6 MJ.m-3, whereas the phosphorescence lifetime remains largely unchanged within the range of 1109-1234 ms. Importantly, this strategy exhibits good generality, as replacing the phosphor only affects the phosphorescence performance while exerting a negligible effect on the mechanical properties.