The Research On Stacked Heterojunction Organic Field Effect Transistor Memory Based On Soluble Semiconductor And Polymer Blend Film

In the field of research and development of memory devices,in the past few years,organic field-effect transistors have attracted widespread attention due to their wide variety of raw materials,simplified manufacturing processes and large-scale production.Another important point is that organic devices can also be fabricated on flexible plastic substrates to complete the bending or folding process of the device,which is also unmatched by many inorganic semiconductor devices such as silicon.Although the development of organic field effect transistor memory is gaining momentum,the research on how the device operates smoothly and whether more data can be stored still needs to be improved.Due to the special properties of heterojunctions,they have always attracted much attention in organic field effect transistor memories.The organic field effect transistor memory with a heterojunction structure is composed of N-type semiconductors and P-type semiconductors,in which holes and electrons are used as the main carriers.Therefore,the heterojunction device can achieve bipolar storage characteristics.At present,as one of the important topics in the research of organic field effect transistor memory,pentacene,the OFET manufactured using it has excellent performance,which can reach the level of inorganic hydrogenated amorphous silicon transistors.However,there is still a disadvantage of using pentacene to make OFETs,that is,the pentacene material has very low solubility and is difficult to dissolve in organic solutions,making it impossible to make organic thin films by spin coating.Therefore,soluble Tips-pentacene has attracted people’s attention,and its device mobility can reach or even exceed current inorganic devices,and more importantly,it has good solubility and is easy to evaporate.In this paper,the blend film formed by Tips-pentacene and polymer is used as the research object.On the basis of the blend film,organic semiconductor materials are evaporated to form a heterojunction structure,thereby preparing a high-performance organic field effect transistor memory.The main research The contents and results are as follows:First,we spin-coated the blend solution of the polymer material polystyrene(PS)and the organic semiconductor material Tips-pentacene using solution processing to generate a phase-separated structure.The coating speed,spin coating time,annealing temperature and time were adjusted to optimize the phase-separated structure of the mixed film,and a single-layer blended film device with better device stability was prepared.Secondly,we sequentially evaporate N-type semiconductor material and P-type semiconductor material on the blend film to form a heterojunction structure,and then select different N-type semiconductor materials to prepare heterojunction devices,and characterize their electrical properties and film morphology.Compared with common organic stacked heterojunction field effect transistor memory devices,it simplifies the fabrication process and effectively improves the storage window and mobility of the device.And the blend film can be used as an organic semiconductor layer and a dielectric layer at the same time,the heterojunction structure based on the blend film has the ability to capture both holes and electrons,and has a large positive and negative storage window,and has good maintenance ability.Finally,after obtaining a heterojunction device with better performance,change the thickness of the N-type semiconductor layer-P13 film in the middle of the heterojunction,characterize the device and compare it,summarize the influence of the thickness of the N-type semiconductor on the device performance,and try to get the heterogeneity storage mechanism of the junction memory.