Inorganic lead-halide perovskite nanocrystals (NCs) are an exciting class
of luminescent materials with high defect tolerance and broad spectral
tunability, but such NCs are vulnerable to degradation under ambient conditions.
Here, we report a class of modular zwitterion-functionalized isopropyl methacrylate polymers designed to
stabilize a wide variety of perovskite NCs of different compositions, while also
enabling processing in green solvents. Specifically, we report polymers in
which the zwitterion spacing is tuned to accommodate the different lattice
parameters of CsPb(Cl<sub>1-<i>x</i></sub>Br<i><sub>x</sub></i>)<sub>3</sub> and
CsPbI<sub>3</sub> NCs, and we report partially fluorinated polymers prepared to
accommodate the needs of infrared-emitting NCs. We show that as-synthesized
CsPbBr<sub>3</sub>, CsPbI<sub>3</sub>, and Yb<sup>3+</sup>:CsPbCl<sub>3</sub>
NCs are easily transferred into these zwitterionic polymers <i>via</i> a simple
ligand-exchange procedure. These NC/polymer composites were then cast into thin
films that showed substantially improved photoluminescence (PL) and stability compared
with more conventional NC/polymer films. Specifically, CsPbBr<sub>3</sub> and
CsPbI<sub>3</sub> NCs in films of their appropriately designed polymers had PL
quantum yields of ~90% and ~80%, respectively. PL quantum yields decreased
under continuous illumination, but self-healed completely after dark storage.
We also found that all the NC compositions studied here maintain their PL
quantum yields in NC/polymer composite films even after 1 year of ambient
storage. These encouraging results demonstrate the utility of such modular zwitterion-functionalized
polymers for hosting specific perovskite NCs, potentially opening avenues for
robust new photonic applications of this important class of NCs.
Modular Zwitterion-Functionalized Poly(Isopropyl Methacrylate) Polymers for Hosting Luminescent Lead-Halide Perovskite Nanocrystals
