The Research Of Organic Transistor Memory With The Core Architecture Processed By A Full Spin-coating Method

Compared with the inorganic memory,organic memories have attracted much attention for their many advantages,such as simple technology,low-temperature processing,low cost and flexible application.Among of many kinds of organic memories,the floating-gate based organic thin-film transistor nonvolatile memory has attracted a great of attention for its advantages of non destructive reading out,nonvolatile memory,a single transistor cell,and good compatibility with integrated circuit.The core architecture of a standard FG-OTFT-NVM device consists of an organic semiconductor layer,a tunneling layer,a floating gate layer and a barrier layer,besides three terminal electrodes.Up to date,there are two characteristics on the research and development of FG-OTFT-NVM.First,there are a few reports in which the FG-OTFT-NVM was fabricated with a top-gate structure.Compared to the bottom gate structure,top-gate structural FG-OTFT-NVM is desirable for its auto-encapsulation of air-sensitive organic semiconductors by the overlaid gate insulator and gate electrode,which can significantly improve the life of storage and use of memory.On the other hand,among of the most previous reports,there are at least one or two functional films of the core architecture,which were processed by the conventional semiconductor technologies with the features of high vacuum,high cost,and high energy consumption.By these methods,not only the advantages of simple preparation,and low-temperature processing,low cost,flexible application were obviously offset,but also the fabrication process of the memory was interrupted due to the change of the different technology for the preparation of the each film of the core architecture.In this study,we propose and fabricate top-gate structural FG-OTFT-NVMs with the core architecture processed by a fully sequential spin-coating method,considering their natural advantages.First,we demonstrate the processing compatibility of the fabrication of the FG-OTFT-NVM,in which the core architecture was built by a fully sequential spin-coating method.A top-gate structural FG-OTFT-NVM was fabricated with p-type polymer P3 HT as the semiconductor layer,polymer PS blending molecular semiconductor TIPS-Pen as the floating-gate,polymer PMMA as the tunneling and blocking layer.The memory performances were extracted.And,the mechanism was analyzed.To resolve the problems,such as the non-zero reading voltage and the relative poor performances in the FG-OTFT-NVM with P3 HT as the semiconductor layer due to holes were trapped/detrapped in/from the floating-gate,the FG-OTFT-NVMs with an abmipolar polymer semiconductor P(NDI2OD-T2)as the active layer were fabricated.The core architecture of the FG-OTFT-NVMs are processed by a fully sequence spin-coating method.The proportion of the PS and TIPS-Pen in the floating-gate layer was optimized.As a result,the memory performances were improved,such as an enhanced memory window,a desired reading voltage of 0 V,and prolonged retention capability in the FG-OTFT-NVM with an optimal structure,attributing to the holes and electrons injecting into the floating-gate and overwriting each other at the supplied wring/erasing voltages,respectively.The overall performance parameters of the optimized FG-OTFT-NVM are comparable to those reported by other state-of-the-art memories.Furthermore,we prepare the single tunneling/floating-gate layer from the blending solution of PS and TIPS-Pen in chlorobenzene,which simplifies the structure and the preparing process of the FG-OTFT-NVM and further highlights its advantages on the processing and cost.The proportion of the PS and TIPS-Pen in the single tunneling/floating-gate layer is optimized.As a result,good memory performances are achieved in the optimal device.Finally,the flexible FG-OTFT-NVMs are fabricated on the PES and PI substrate,respectively,with their core architecture is prepared by a fully sequence spin-coating method.The both memories exhibit obvious nonvolatile memory characteristics.Our research results demonstrate that it is possible to fabricate FG-OTFT-NVMs with its core architecture processed by a fully sequence spin-coating method,which has a great advantage in the fields of low-temperature and large-are processing,the energy consumption and cost,compared to the floating-gate memory based on Si semiconductor.Our research also exhibit that the FG-OTFT-NVM possess a promising application in the field of flexible,wearable electric devices.