Quantum dot light-emitting diodes (QLEDs) are emerging as promising contenders for next-generation display technology owing to their remarkable performance. In extensive research on QLEDs, MoO3 is commonly used as a replacement for the acidic hole injection material

PEDOT:PSS to avoid acid corrosion of the indium tin oxide (ITO) electrode, thus preventing degradation of QLED performance. The advantages of solution-processed QLEDs make them an attractive option for large-scale production. Nowadays, achieving pixelation is still a

critical step in the commercialization of QLEDs. In this work, we synthesized ultrafine MoO3 nanoparticles with an average grain size around 2 nm and successfully achieved MoO3

patterns through direct photolithography by incorporating photosensitizers. Furthermore, QLED devices with the photolithographed MoO3 as the hole injection layer (HIL) were fabricated, and pixel patterns with different shapes were designed and achieved. Compared to QLEDs based on pristine MoO3, the devices with photolithographic MoO3 exhibited a higher external quantum efficiency (EQE) and brightness. We believed that this work could establish a technological foundation for the development of high-resolution QLED displays.