Metal halide-based perovskites, with their exceptional photoelectric conversion efficiency, are promising materials for photodetectors and image sensors. Achieving high-definition optical imaging requires not only high-quality perovskite materials but also effective patterning methods. Here, we show the fabrication of pixelated photodetector arrays through a two-step process: (1) direct optical patterning of CsPbBr₃ perovskite nanocrystal films using ligand cross-linkers, and (2) post-patterning ligand-exchange process. The direct optical patterning achieves high-resolution (≈2 μm in pixel sizes), uniform CsPbBr₃ nanocrystal film patterns over 2-inch wafers. The ligand-exchange process replaces the long hydrocarbon ligands and cross-linkers with compact ionic ligands, which enhance the charge transport efficacy without compromising the quality of the patterned films. Consequently, the patterned photodetectors, in the photoconductor configuration, show responsivity (0.11 A W⁻¹) and specific detectivity (1.81×10¹¹ Jones) on par with their non-patterned counterparts. These features permit the creation of pixelated photodetector arrays that minimize the charge-sharing crosstalk effect and enable improved imaging capabilities. This work shows a promising approach in building high-performance perovskite image sensors.

Direct photopatterning is a powerful strategy for patterning colloidal quantum dots (QDs) for their integration in various electronic and optoelectronic devices. However, ultraviolet (UV) exposure required for QD patterning, especially those with short wavelength (e.g., deep UV light), can degrade the photo-, and electroluminescence, and other properties of patterned QDs. Here we develop a photosensitizer-assisted approach for direct photopatterning of QDs with h-line (centered at 405 nm) UV light and better preservation of their luminescent properties. This approach uses a photosensitizer that can absorb the h-line UV light and transfer the energy to activate bisazide-based crosslinkers via Dexter energy transfer. Uniform, high-resolution (smallest feature size, 2 μm), and full-color patterns of red, green, and blue QD layers can be achieved. The patterned QD layers maintain up to ~ 90% of their original photoluminescent quantum yields, comparing favorably with those (< 60%) of QDs patterned without photosensitizers. We further extended the strategy to the direct three-dimensional (3D) printing of QDs. This photosensitizer-assisted approach offers a new way for direct two-dimensional (2D) photopatterning and 3D printing of colloidal QDs, with implications in building high-performance QD optoelectronic devices.