Low‐Power Direct Photopatterning of Colloidal Quantum Dots

ABSTRACT

Quantum dot light‐emitting diodes (QLEDs) require high‐resolution photopatterning of quantum dots (QDs) while preserving their optoelectronic properties, yet this remains a major challenge. Here, we systematically investigate the influence of bridge‐group conjugation on photolithographic performance by modulating the π ‐conjugation of azide crosslinkers. A highly π ‐conjugated tetraphenylethylene (TPE)‐based crosslinker exhibits a molar extinction coefficient (ɛ) exceeding 60,000 L mol ^{− 1} cm ^{− 1} , enabling low‐dose, non‐destructive photolithography. High‐fidelity red, green, and blue QD patterns with a resolution of 12,700 PPI are achieved under an ultralow UV exposure dose of only 3 mJ cm ^{− 2} in air. The excellent optical retention originates from the reduced UV exposure requirement together with favorable energy‐level alignment between the crosslinker and QDs. Full‐patterned R/G/B QLEDs exhibit peak external quantum efficiencies of 20.79%, 15.27%, and 3.99%, respectively, with device performance approaching or even surpassing that of pristine devices. This highly π ‐conjugated crosslinker design provides a general strategy for low‐power, non‐destructive QD photolithography and paves the way for scalable fabrication of ultrahigh‐resolution QLED displays.