All-Optically Switchable Platform Based on Phase-Change Material for Light-Emitting Device

Over the past decade, phase-change materials (PCMs) have found widespread use across photonics, optoelectronics, and electronics. Their ability to reversibly tune optical and electronic properties through phase switching is increasingly being leveraged to enhance device functionality. Here, we develop a new optoelectronic device that integrates a perovskite emitter with a phase-change material. We demonstrate reversible "on/off" control of electroluminescence emission through PCM phase switching as well as the ability to write distinct emission patterns by locally modifying the PCM phase without lithography. These results highlight a pathway toward new classes of fast-response LEDs with reconfigurable and repeatedly rewritable emission patterns.