Direct-writing large-area cross-aligned Ag nanowires network: toward high-performance transparent quantum dot light-emitting diodes

Flexible transparent electrodes (FTEs) made of silver nanowires (AgNWs) have been widely used in wearable and foldable electronics devices. For obtaining FTEs with both high transparency and low resistance, the AgNWs network should be highly cross-aligned with a low density. Various solution processes have been developed, but most suffer from poor control of the distribution of the AgNWs. Here, we developed a facile direct-writing solution process guided by a conical fiber array (CFA) for preparing large-area highly cross-aligned AgNW networks with low density. The CFA enables both fine-tuning the triphase contact line during the film formation and the soft conformal contact with the substrate to facilitate multiple liquid transfers without deteriorating the underlayer. Consequently, a high-performance FTE was prepared, showing a transmittance of 93.8%, a sheet resistance of 21.4 Ω sq⁻¹, and good stability against bending. With this process, a large-area transparent quantum dot light-emitting diode (T-QLED) device was fabricated, which gives an impressive external quantum efficiency of 15.47% (indium-tin oxide [ITO] side: 7.17%; FTE side: 8.3%). Moreover, we also demonstrated a large-area flexible T-QLED. We envision that these results will shed new light on easy fabrication of high-performance FTEs.