The Polymer Society of Korea

박교빈 (포항공과대학교)

정대성 (포항공과대학교)

Short-Wave Infrared (SWIR) photodiodes have gained strong interest for medical imaging, military surveillance, and industrial automation. However, InGaAs-based devices are incompatible with CMOS and require costly fabrication. Quantum dots (QDs) provide a low-cost, bandgap-tunable alternative, but long-wavelength SWIR QDs suffer from poor stability due to large particle sizes.

Here, a polymer–QD hybrid strategy is proposed to improve film quality and stability. An azide-functional ligand (FPA-S) enables photo-induced crosslinking between QDs and polymers, effectively suppressing phase separation. The resulting SWIR photodiodes exhibit over 80% external quantum efficiency at 1600 nm, a dark current density of 20 nA/cm² at −0.5 V, and breakdown voltages beyond −20 V.