Enhanced the thermal/chemical stability of Cu NWs with solution-grown Al2O3 nanoshell for application in ultra-flexible temperature detection sensors

The research of transparent electrode has always been a hot topic, but the lack of low cost and high stability flexible transparent electrode has hindered the development of flexible electronics, which has become a non-negligible obstacle. Here, we report a simple, low-cost, all-solution method for self-assembly growth of Al2O3 nanoshells on copper nanowires (Cu NWs), which improves the photoelectric properties of Cu NW as well as its thermal and chemical stability. The reaction of Al3+ and Cu atoms occurs in the presence of water, and a reasonable mechanism of Al2O3 formation is proposed. The Al2O3 nanoshell-coated Cu NWs network shows low sheet resistance of 15.6 Ω/sq with the optical transmittance of 84.7%. In addition, Al2O3@Cu NWs network exhibits excellent stability in a range of harsh environments (strong oxidation, high temperature and humid conditions), even comparable to Ag NWs. More importantly, based on the principle that copper metal resistivity varies with temperature, and taking advantage of the excellent stability and enhanced high temperature resistance of Al2O3@Cu NWs, we proposed an Al2O3@Cu NWs/PVDF composite temperature sensor. The ultra-thin, stable characteristics and unique semi-embedded structure and the ability of can being perfectly fitted to the skin, making it have great application potential in wearable flexible electronics and great guiding significance for the development of electronic skin.