Air-processed, ultraresponsive NIR photodetectors using 2D perovskite hybrids

Halide perovskites have shown tremendous potential as active materials in various optoelectronic devices, including solar cells, light-emitting diodes and photodetectors. However, their relatively large bandgaps - typically limited to ∼1.40 eV (∼885 nm) - constrain their use as near-infrared (NIR) photodetectors. Here, we present a novel two-dimensional (2D) hybrid perovskite (PDA)₂PbI₄ (PDA = 6-phenyl-3,5-hexadiynylammonium), which upon thermopolymerization forms (poly-PDA) PbI₄ (polyPDA = polymerized PDA). This material can be incorporated into NIR photodetectors exhibiting record-high responsivities of up to 10⁷ A W^-1 and external quantum efficiencies of up to (128.0 ± 3.6)% at 980 nm under a 4 V bias. Notably, the devices can be fabricated, operated, and stored entirely under ambient air conditions, highlighting their stability and processability.