BODIPY‐Pt‐Porphyrins Polyads for Efficient Near‐Infrared Light‐Emitting Electrochemical Cells

Abstract

The synthesis, characterization, and application in light‐emitting electrochemical cells (LECs) of two near‐infrared (NIR)‐emitting Pt‐porphyrins (Pt‐por) with none or 20 F atoms and their respective Pt‐por polyads containing from 1 to 4 BODIPY (BDP) units (PtBDP) connected via tetra‐fluorophenyl triazole spacer groups are reported. The functionalization of PtBDPs is tuned with respect to the number of BDP units and F atoms optimizing 1) the NIR emission through an efficient energy transfer from the BDP to the Pt‐por core, 2) the electronic structure to decouple charge transport via BDP and exciton formation at the Pt‐por, and 3) the ionic conductivity in thin films. A comprehensive rationale on how the molecular design rules the device performance is provided, achieving LECs with emission at 780 nm. This is realized using PtBDP‐2‐8, in which a host:guest strategy between BDP and Pt‐por in thin films is fully operative accompanied by an optimal ionic conductivity. This is supported by spectroelectrochemical findings and device analysis with both Pt‐por references and the PtBDP series. Overall, this work highlights that Pt‐porphyrins are efficient emitters in developing NIR LECs due to their rich functionalization, enabling to control charge transport, energy transfer, and ionic conductivities.

Keywords

• carrier trapping
• host:guest
• light-emitting electrochemical cells
• near-infrared emission
• porphyrin polyads