Influence Of Carbon Nanomaterials Doping On Organic Thin-Film Transistor And Its Gas Sensing Properties

As one of the key components of modern electronic technology,Organic thin-film transistor(OTFT)has good biocompatibility and flexibility,giving it a wide range of application prospects in the field of wearable electronic products.Among them,the gas sensor based on OTFT has the advantages of flexible material design,working at room temperature and realizing multi-parameter detection,etc.,and can be used as an excellent detection platform for toxic and harmful gases.In recent years,researchers have mainly focused on OTFT-based high performance gas sensor research in four aspects:OSCs material molecular design,device structure,preparation technology,function layer and interface control.This paper focuses on the morphology control of the functional layer of the device,introduces two carbon nanomaterials including OH-MWCNTs and GO into active layers by blend solution at room temperature,and studies the influence of carbon nanomaterial doping on device performance and gas sensing characteristics.The specific research contents are as follows:1.The effects of OH-MWCNTs and GO doping on the electrical properties of OTFT were studied.With the introduction of OH-MWCNTs,the electrical performance of the device had been improved to a certain extent,which was attributed to the electrical conductivity of OH-MWCNTs.On the contrary,the introduction of GO bringed about a decrease in the electrical performance of the device.The reason was that GO doping bringed about a decrease in the order of the P3HT molecular chains,which in turn affected the transport of carriers.2.The effect of P3HT/OH-MWCNTs on the gas sensing characteristics of OTFT was studied.Using P3HT/OH-MWCNTs with different blend ratios as the active layer,a highly responsive NO₂ sensor was fabricated.Compared with the pure P3HT device,the10:1 device had the best sensing performance,and the current responsivity was improved by ca.10 times at 30 ppm.At the same time,the device also had good gas selectivity.Combined with the morphological characterization of the films,we believed that the introduction of OH-MWCNTs promoted the agglomeration of P3HT,and the gap created by larger agglomerates provided more space for the adsorption and interaction of NO₂,thereby achieving an improvement in gas sensitivity response.3.Inspired by the P3HT/OH-MWCNTs blend system,the influence of the P3HT/GO blend system on the gas sensitivity characteristics of OTFTs was further studied.The experimental results showed that the doping of GO could also effectively improved the gas-sensing characteristics of the device.Combined with the characterization results,we speculated that the doping of GO made the surface of the film rougher and effectively increased the area of interaction with NO₂.Eventually lead to an improvement in the gas sensitivity response.In summary,this work explores the possibility of achieving high-performance OTFT gas sensors through OH-MWCNTs and GO doping,and specifically analyzes the sensing mechanism of improving gas sensing characteristics.In addition,the selectivity is also studied for the practicability of the blend device.This simple solution blend method of carbon nanomaterial doping will provide a new idea and method for the preparation of high performance and low cost gas sensors based on OTFT.