Efficient Photoinduced Living Polymerization Driven by Shortwave Infrared CuInSe₂/CuInS₂ Quantum Dots

Shortwave infrared (SWIR) light-driven photoinduced electron/energy transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization holds great promise for applications such as 3D printing and transdermal photopolymerization. However, efficient SWIR-active photocatalysts remain lacking. Herein, we report the use of lead-free CuInSe₂/CuInS₂ core/shell quantum dots (QDs), with their absorption onset extending to 1100 nm, to drive efficient SWIR PET-RAFT polymerization. Time-resolved spectroscopy reveals that both band-edge and trap-state electrons can transfer to the RAFT agent. The relatively sluggish hole transfer, due to hole localization to copper states, can be accelerated by introducing amines as hole scavengers. The reaction exhibits well-defined characteristics of living polymerization and proceeds efficiently in the presence of a 3 mm biological tissue barrier under 1050 nm irradiation.