Flexible QLED array with mechanical force modulation of electroluminescence intensity

Abstract: Functional signal conversion devices are critical components of next-generation intelligent systems, driving an urgent demand for novel sensing materials and functionalities to enable advanced applications in intelligent robotics and human–machine interfaces. In this work, we present a quantum dot light-emitting diode (QLED) array based on a newly developed signal conversion functional material 20% Gd-doped CeO_2−x (CGO). Under pressure and electric field induction, the oxygen vacancy dynamics in CGO were modulated, resulting in macroscopic polarization charges, reflecting the mechanical force-electrical response effect. The QLED pixel emission intensity was controlled by external pressure, achieving a remarkable 1000% enhancement at 1.8 GPa. Combined with resolution-tunable Si MWs array, mapping of 2D pressure distribution on external objects with optical signals was realized. This work extends the force-electrical-optical signal conversion mechanism to centrosymmetric cubic fluorite materials, overcoming the traditional limitations of piezo-phototronic devices that rely on specific crystal symmetries, and provides new avenues for the development of the next-generation smart sensing.