Organic Thin Film Transistor Memory Based On Polycyclic Aromatic Semiconductors:Design And Performance

Organic semiconductor materials' wide application in the the fields of organic light emitting diodes,organic thin film transistors,organic photovoltaic devices,and bioimaging and sensing has promoted the development of organic electronics.Transistor memory has a wide range of applications in the field of organic electronics,traditional transistor storage is based on a silicon-doped active layer.The device fabrication process has high requirements for temperature,environment,and cost.In recent years,the organic-semiconductor-active-layer-based field-effect-transistor memory has the advantages of low cost,low power consumption,simple preparation process,compatibility with a flexible substrate,which has attracted the attention of researchers.The common organic-effect transistor memory is based on a double heterojunction structure,which has a complex device structure,a slow write operation,a high preparation cost,and poor storage stability.To address this issue,we intend to use a high-mobility polycyclic aromatic hydrocarbon organic/polymer material to construct a single active layer field effect transistor memory.Our study mainly includes three parts:(1)We have screened of a batch of PAHs with higher mobility through structural designing,A high mobility material DPP-C16 which reached 0.1 cm2/V·s was obtained.After Comparing with the four materials containing the same unit,we have got PIDTI-BT and PIDTI-DTBT which have a mobility of 0.005 cm2/V·s and 0.003 cm2/V·s respectively.Meanwhile they have a memory window of-42 V and-45 V.The material structure's characteristics was comprehensive evaluated to get the design ideas.Providing materials and device structure support for the next step.(2)We have studied the the storage and mobility characteristics of optically active materials PIDTI-BT and PIDTI-DTBT in the light and dark field conditions,the effects of different mixed concentrations and types of molecular additives on the electrical properties and storage performance of the field-effect transistor memories were obtained.After adding 2 % volume fraction of dimethyl sulfoxide,the device has the best electrical properties and mobility reaches 10-2 cm2/V·s was screened out by AFM,SEM morphology characterization and electrical performance testing.Memory performance also has big improvement.The storage performance has been improved.The PIDTI-DTBT memory window has been increased from-45 V to-86 V.(3)Different thickness OFETs prepared by the material DTBCz and ?ChDT-DTDFBT were researched,a single-layer field effect transistor having no dependence on film thickness was obtained.Their thickness above 100 nm can still obtain higher yields and 10-3 cm2/V·s orders of magnitude mobility.Meanwhile ?ChDT-DTORBT has achieved 10-4 cm2/V·s order mobility at 164 nm thickness.In a word,our work has analyzed the advances in the research of OFET memory,targeted design materials,designed device structure,researched device preparation process.A reasonable approach has been achieved by the design of transistor memory materials,and the performance of PAHs-based organic field-effect transistor memories was be tuned.