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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.

Here, the photo-enhanced behavior in LPG sensing of hydrothermally synthesized BaFe12O19 nanorods at room temperature under visible light radiation has been thoroughly inspected and reported. The sensing element is observed to be poorly responsive towards LPG in dark conditions at room temperature, while it reveals a good photo response in presence of visible light of 30 mW/cm2, and the visible light aids in improving the LPG sensing response up to a great extent at room temperature. Under the irradiation, the nanorods are found to detect the presence of LPG molecules of concentration as small as 0.5 vol% at the response and recovery times ~5.02 s and ~10.10 s respectively. The sensitivity of the visible-light induced material was evaluated ~41.27 sensor response/vol% with the maximum sensor response as high as 108, whereas, in dark, the same material showed a maximum response of ~6.64 with a sensitivity of merely 1.94 sensor response/vol%. The photo-generated carriers are suggested to be responsible for achieving a significant, stable, fast response in presence of LPG. This is the first ferrite based visible light-induced LPG sensor.

In this study, dual-layered self-healable LPG sensor which can successfully re-establish both of its structural and sensing properties after an external deformation occurred, has been reported. Here Ni0.4Zn0.6Fe2O4 (NZF) works as a highly sensitive LPG sensor which can detect LPG well below the lowest explosion limit (LEL) efficiently. The self-healing phenomenon has been achieved by urea-formaldehyde (U-F) microcapsules encapsulating NZF and linseed oil. The dual-layered self-healable sensing film is prepared by forming a lower layer using urea-formaldehyde (U-F) microcapsules capturing linseed oil and NZF, serving as healing layer, and an upper layer using NZF aiding sensing phenomenon. LPG sensing parameters like sensitivity, sensor response, recovery time and response time were investigated in case of both uncracked sample and healed sample to get a clear idea of how much sensing properties were recovered after healing took place. The minimum response and recovery times of the uncracked film corresponding to 0.5 vol.% LPG concentrations were found to be 28.08 s and 52.46 s respectively, whereas, the same after healing were as 34.39 s and 45.17 s respectively. After healing, ∼ 86.4 % sensitivity was restored. This is the first dual-layered microcapsule-based LPG sensor, which has healing property.