ABSTRACT High‐performance flexible quantum‐dot light‐emitting diodes (QLEDs) are of critical importance for advancing the development of photodynamic therapy (PDT). However, conventional bottom‐emitting QLEDs are severely constrained in PDT applications by limited light outcoupling efficiency (OCE), emission directionality, and substrate compatibility. Here, we report a high‐performance top‐emitting flexible QLED (F‐QLED) fabricated on a polyethylene naphthalate (PEN) substrate. By incorporating a transparent composite electrode silver (Ag)/indium zinc oxide (IZO), the device not only preserves a high OCE while enhancing current density but, more importantly, significantly improves the mechanical robustness and emission uniformity. As a result, the F‐QLED achieves a peak external quantum efficiency (EQE) of 34.9%. After integrating an ultra‐cooling patch (UCP) with high thermal conductivity onto the device, the maximum power density at a driving voltage of 6 V is increased from 55 to 63 mW/cm 2 , while the operational lifetime (T 90 ) at an initial power density of 40 mW/cm 2 is extended from 75 to 153 h. Finally, by employing an elastic encapsulation strategy based on styrenic block copolymer elastomers, the device exhibits excellent skin conformability and operational stability under ambient conditions. These results establish a reliable technological pathway toward the realization of wearable phototherapeutic devices.
Chen et al. (Tue,) studied this question.