Multispectral Oxide Phototransistor Array via Electrohydrodynamic Subpixel QD Patterning and Engineered IGZO Channels for Persistent Photoconductivity Suppression

ABSTRACT Achieving scalable, color‐discriminative, and fast‐recovering oxide phototransistors remains a challenge due to persistent photoconductivity (PPC) and complex sensitizer integration. Here, we present a 21 × 7 indium‐gallium‐zinc oxide (IGZO) phototransistor array that realizes high‐fidelity multispectral color sensing by integrating oxygen plasma‐treated oxide channels with electrohydrodynamic (EHD) jet‐printed CdSe quantum dots (QDs). This lithography‐free process enables precise subpixel patterning of red and green QDs, while preserving the pristine IGZO's native blue sensitivity. Oxygen plasma treatment effectively suppresses oxygen vacancy‐related traps, leading to minimized PPC and fast recovery. Systematic thermal annealing optimizes the QD/IGZO interface for enhanced charge transfer and spectral selectivity. At 200°C, the red, green, and blue subpixels (λ = 635, 532, and 405 nm) achieve photoresponsivities of 3.12 × 10 4 , 2.60 × 10 4 , and 1.40 × 10 4 A/W; photosensitivities of 2.60 × 10 6 , 7.27 × 10 5 , and 1.46 × 10 5 ; and specific detectivities of 4.39 × 10 13 , 1.01 × 10 13 , and 1.94 × 10 12 Jones. The devices show robust cycling stability and sub‐second recovery under repeated RGB illumination over 4000 s. This work offers a scalable, material‐efficient platform for PPC‐suppressed, spectrally selective oxide phototransistor arrays, enabling advanced color sensing and integrated optoelectronics.