Improved sensing behaviour of self-healable solar light photodetector based on core-shell type Ni0.2Zn0.8Fe2O4@ poly (Urea-Formaldehyde)

In this work, a bilayered ultra responsive self-healable photodetector that can restore both its structure as well as sensing property after deformation has been reported. This photodetector is based on ferrite with ultrafast sensing ability along with restoration property. In this dual-layered structure, the upper layer is Ni0.2Zn0.8Fe2O4 (NZF) prepared by citrate gel method and acts as sensing layer, whereas, the lower layer is Urea-Formaldehyde (U-F) microcapsules with flaxseed oil and NZF core. Here bottom layer acts as a healing layer, which can successfully restore film sensing property after deformation. Flaxseed oil acts as a medium to transport NZF from lower layer to the upper sensing area, which was deformed manually. The evaluated photoresponse and recovery time of NZF before deformation are 1.74 sec and 3.28 sec at 100 mW/cm2 respectively, whereas, response and recovery after healing were 1.75 sec and 2.84 sec respectively. The solar light photodetector based on microcapsule that can restore its sensing property ∼98.5%. The purpose of this work is to develop a method by which anyone can fabricate the different types of self-healable solar light photodetector.