Stable P-Type PbS Quantum Dot Ink for All-Blade-Coated Short-Wavelength Infrared Photodiodes

However, current photodetectors rely on p-type CQD layers fabricated via a laborious, defect-prone layer-by-layer process. While robust n-type CQD inks have been realized, p-type inks remain challenging due to the absence of suitable ligands and solvents.

An ideal solvent must ensure colloidal stability and be orthogonal to underlying layers. Here, we report a thiolate-capped p-type PbS CQD ink using mercapto-2-propanol as the ligand and hexafluoro-2-propanol as the solvent. Stabilization arises from ligand–solvent hydrogen bonding, providing a shelf-life exceeding six days.