Self-Healable Capacitive Photodetectors with Stretchability Based on Composite of ZnS:Cu Particles and Reversibly Crosslinkable Silicone Elastomer

Recent studies are actively contributing to the implementation of the use of five human senses in electronic skins. In order to achieve this, it is critical to develop sensors with the ability to heal after being subjected to stretching or damage; this should be achieved without any significant deterioration in performance, as is possible for human skin. This study investigates the potential for producing stretchable, cuttable, and healable photodetectors. To this end, a reversibly cross-linkable silicone polymer, polydimethylsiloxane (rcPDMS), is synthesized via a Diels-Alder reaction; subsequently, ZnS:Cu particles are dispersed therein to form a composite film. Ag nanowires (AgNWs) are formed on both the surfaces of the film to realize a three-layer sandwich structured capacitor, namely: AgNWs/ZnS:Cu-rcPDMS/AgNWs. Light irradiation of the film induces the photodielectric effect in ZnS:Cu particles and the dielectric response of photoinduced dipole moments composed of localized photoactive carriers results in a change in the capacitance of the film. Based on this, a photodetector is developed that is stretchable, healable, and demonstrates no reduction in the device performance even before and after cutting as well as healing.