Preparation And Characterization Of Floating Gate Memory Based On Organic Field Effect Transistor

As the main carrier of information storage,transmission and communication,memory is increasingly indispensable in people's daily life.OFET-type floating gate memory has become an important research direction of organic memory devices,because of its nondestructive readout,single transistor transmission and compatibility with CMOS.In this paper,the OFET-type memory is fabricated using the polysilicon and the carbon quantum dots as the floating gate.Moreover,and the device characteristics has been analyzed.The main contents are as follows:An OFET-type floating gate memory with the structure of n⁺⁺-Si/SiO₂/poly-Si/Poly?methyl-methacrylate??PMMA?/pentacene/Au has been developed.The experimental results show that with the increase of the thickness of PMMA tunneling layer,the mobility of the device,the channel current of the device under the same gate voltage and the storage window decrease.Too long or too short annealing time affect the roughness of the tunneling layer resulting in poor device characteristics.The results of testing the OFET-type floating gate memory charge retention time show that the carriers stored in the polysilicon floating gate are quickly lost in 100 s,and only 40%of the initial value after 1000 s.Carbon quantum dots was prepared using one-step microwave synthesis and applied to OFET-type floating gate memory.Devices with n⁺⁺-Si/SiO₂/C-QDs+PVP/pentacene/Au and n⁺⁺-Si/SiO₂/PVP/pentacene/Au structure have been developed.The results show that the concentration of carbon quantum dots affects the roughness of each functional layer of the device.When the solution concentration is 1:1 for carbon quantum dots and anhydrous ethanol,the device has the best characteristics.The OFET-type carbon quantum dots/PVP hybrid floating gate memory was programmed and erased under illumination.The storage window and charge retention time of the memory were increased successfully by light assistance.An OFET-type double floating gate memory with n⁺⁺-Si/SiO₂/poly-Si/C-QDs/PMMA/pentacene/Au structure has been developed.The results show that carbon quantum dots can improve device characteristics,increasing device mobility from 0.04cm² V^-1 s^-1 to 0.06 cm² V^-1 s^-1,enhancing device charge retention time and a nearly 40V memory window was obtained when programming and erasing voltage V_P/V_E=±55 V.