Research On Preparation Of Pd Composite Film Flexible Hydrogen Sensor Based On AAO

In today's era,clean energy has become a hot topic of global research due to the increasing environmental pollution,non-renewability of fossil fuels and Greenhouse effect.Hydrogen,as a clean energy,can effectively solve these issues.In recent years,researchers have focused on new types of hydrogen sensors such as semiconductors,thermoelectric,optics and so on.Especially,metal palladium?Pd?plays an important role in most hydrogen sensors among them.In fact,Pd is widely used in hydrogen gas sensors for its special ability to absorb hydrogen gas at a normal temperature and pressure.At the same time,studies have found that some integrated circuit boards have to use flexible materials to enhance their working life,and wearable devices made of flexible materials can increase functionality.The research content of this thesis mainly includes the following parts:First of all,we studied the preparation process of flexible PDMS film using the anodic aluminum oxide?AAO?template,then measured the characteristic parameters of the flexible film including thickness and elasticity.The best spin coating rate in the test was 300 r/min.Then we prepared PDMS substrates templates using three different templates and 10 nm Pd was sputtered to prepare three hydrogen sensors.The performance of three sensors were tested including responsivity,response time,recovery time,and stability.We found that the flexible PDMS/Pd membrane hydrogen sensor prepared using AAO template with the highest surface roughness produced nanoscale cracks and have faster response time and recovery time of 3s/4s,respectively.Then,the effect of Pd film thickness on the performance of this kind of hydrogen sensor were studied.Pd layers with three different thickness of 6 nm,10 nm and 20 nm on a PDMS substrate were prepared and their performance were tested.Hydrogen sensor with 10 nm-thick Pd thin film performs best.Finally,the Pd-titanium dioxide?TiO₂?composite thin film flexible hydrogen sensor based on PDMS flexible film prepared by AAO template were studied.First,the performance of hydrogen sensors with and without TiO₂ were studied.We have found that the addition of TiO₂ improves the device's response and recovery speed.We prepared three hydrogen sensors with TiO₂ films thicknesses of 6 nm,10 nm,and 12 nm and sputtered 30 nm Pd to test their performance.The results showed that the response time and recovery time point of the three samples were discrete.The sample with 6nm TiO₂showed the best performance.Response time and recovery time were improved to 5 s/6 s respectively.