Solution‐Processed Stretchable Ag₂S Semiconductor Thin Films for Wearable Self‐Powered Nonvolatile Memory

Abstract Compared with the large plastic deformation observed in ductile metals and organic materials, inorganic semiconductors have limited plasticity (<0.2%) due to their intrinsic bonding characters, restricting their widespread applications in stretchable electronics. Herein, the solution‐processed synthesis of ductile α‐Ag₂S thin films and fabrication of all‐inorganic, self‐powered, and stretchable memory devices, is reported. Molecular Ag₂S complex solution is synthesized by chemical reduction of Ag₂S powder, fabricating wafer‐scale highly crystalline Ag₂S thin films. The thin films show stretchability due to the intrinsic ductility, sustaining the structural integrity at a tensile strain of 14.9%. Moreover, the fabricated Ag₂S‐based resistive random access memory presents outstanding bipolar switching characteristics (I_on/I_off ratio of ≈10⁵, operational endurance of 100 cycles, and retention time >10⁶ s) as well as excellent mechanical stretchability (no degradation of properties up to stretchability of 52%). Meanwhile, the device is highly durable under diverse chemical environments and temperatures from −196 to 300 °C, especially maintaining the properties for 168 h in 85% relative humidity and 85 °C. A self‐powered memory combined with motion sensors for use as a wearable healthcare monitoring system is demonstrated, offering the potential for designing high‐performance wearable electronics that are usable in daily life in a real‐world setting.