Electrical Bistable Devices Based On Flexible/transparent PEDOT?PSS/CH₃NH₃PbI₃ Films

Today,the traditional inorganic storage devices are limited for the next generation electronic devices due to their properties,such as:complicated process,high production cost,rigid device substrate and so on.In addition,with the emergence of the novel flexible transparent electronic products in the market,organic semiconductor devices have attracted due to their convenient synthesis,simple fabrication process,low cost,flexibility,transparency,and large area production.In this work,the electrical bistable devices were first demonstrated based on the PEDOT:PSS/CH3NH3PbI3 flexible/transparent films.The devices exhibit a good electrical bistability,and the underlying working mechanisms are studied.The main work is as follows:(1)The perovskite active layers were prepared by the one-step method and two-step method respectively.The morphology of the proposed films was characterized by scanning electron microscopy(SEM).The results show that the perovskite film prepared by the one-step method is smoother and more crystalline.The Al/CH3NH3Pbl3/PEDOT:PSS/ITO/Gla ss and Al/CH3NH3PbI3/ITO/Glass devices were fabricated based on the active layer prepared by the one-step method.It was found by ?-? test that the devices without PEDOT:PSS layer has no electrical stability,which indicates that PEDOT:PSS is the key to achieve electric bistability.At the same time,the performances of the one-step and the two-step based devices with the same structure of Al/CH3NH3PbI3/PEDOT:PSS/ITO/Glass are studied.The result shows that the one-step based device is more stable and exhibits the better device performance.The device behavior is consistent with the SEM imagine.Finally,the ?-? curve of the device is theoretically fitted to investigate the underlying working mechanism.(2)The film transmittance is controlled by the film coating speed and the concentration of the solution.By optimizing the parameters,the transparent perovskite films are obtained.?-? test results show that the coating speed and the solution concentration can significantly affect the electrical bistability of the devices.It was found that reducing the concentration of the solution can not only increase the film transparency but also enhance the electrical bistability of the device.The light transmittance of the CH3NH3PbI3(10 wt%)/PEDOT:PSS/ITO/Glass in the visible range can reach 75%.(3)The perovskite electrical bistable devices were first demonstrated based on the flexible substrate PET with the structure of(Al/CH3NH3Pbl3/PEDOT:PSS/ITO/PET).With the?-? test,the continuous "write-read-erase-read" cycle pulse test,and the duration measurement,the bistable on/off ratio is more than 103 and can continuously work in the air quite stably.Finally,the working mechanism of the device is studied by theoretically fitting the ?-? curve.(4)The transparent devices of Mo03/Ag/Mo03/CH3NH3PbI3/PEDOT:PSS/ITO/Glas s were demonstrated and the result of ?-? test shows that the device has the characteristics of electrical bistability.