White‐Light Emission from Dual‐Way Photon Energy Conversion in a Dye‐Encapsulated Metal–Organic Framework

The design of white‐light phosphors is attractive in solid‐state lighting (SSL) and related fields. A new strategy in obtaining white light emission (WLE) from dual‐way photon energy conversion in a series of dye@MOF (LIFM‐WZ‐6) systems is presented. Besides the traditional UV‐excited one‐photon absorption (OPA) pathway, white‐light modulation can also be gained from the combination of NIR‐excited green and red emissions of MOF backbone and encapsulated dyes via two‐photon absorption (TPA) pathway. As a result, down‐conversion OPA white light was obtained for RhB⁺@LIFM‐WZ‐6 (0.1 wt %), BR‐2⁺@LIFM‐WZ‐6 (2 wt %), and APFG⁺@LIFM‐WZ‐6 (0.1 wt %) samples under 365 nm excitation. RhB⁺@LIFM‐WZ‐6 (0.05 wt %), BR‐2⁺@LIFM‐WZ‐6 (1 wt %) and APFG⁺@LIFM‐WZ‐6 (0.05 wt %) exhibit up‐conversion TPA white light under the excitation of 800, 790, and 730 nm, respectively. This new WLE generation strategy combines different photon energy conversion mechanisms together.