基于敏化作用近红外响应有机场效应晶体管的研究

NIR Phototransistors Based on Sensitization

近红外响应有机场效应晶体管(NIR OFETs)在健康监控、疾病诊断方面拥有巨大的潜力。能实现近红外响应的有机场效应晶体管要求有机半导体层具有高迁移率以及强近红外吸收性能,但是兼具这2种属性的有机半导体材料较少,发掘现有材料自身潜力、探索新的制备工艺以实现器件性能的提高是一个很好的解决方法。笔者借鉴染料敏化太阳能电池中“敏化”的概念,用聚(2,5-双(3-十四烷基噻吩-2-基)噻吩并[3,2-b]噻吩)(PBTTT)薄膜作为电荷传输层,噻吩稠合的吡咯并吡咯二酮和噻吩的共聚物(P1)和[6,6]-苯基-C71-丁酸异甲酯(PC71BM)共混溶液制成的薄膜为红外吸收层,再通过真空热贴合(层压)的方式,成功制备了NIR OFETs的活性层。结果显示,层压器件较好地保留了2种材料各自的特性,在光强为52.7μW/cm^2的微弱的近红外光(λ=850 nm)照射下、沟道长度为40μm时,迁移率为0.0078 cm^2/(Vs),开关比为31739,光暗电流比为113.49,光响应度为0.12 A/W。

In order to study the multiphase flow and heat transfer laws of restart-up process for deep water oil and gas pipelines this paper establishes a mathematical model for the restart-up process of deep water pipelines,and provides definite conditions and solution for the model in combination of heat transfer and multiphase theory.With this model,the change laws of temperature and pressure parameters in the restart-up process of deep-water pipelines are simulated.Based on this,it carries out a prediction on generations of hydrate and an analysis on parameter sensitivity.Research results show that the start-up flow rate,thermal conductivity and thickness of insulating layer can improve the temperature distribution of fluid in the pipeline greatly,and the bigger the start-up flow rate is,the smaller the thermal conductivity is;the bigger the thickness and the higher temperature of fluid in the pipeline are,the less the risk of generation of hydrate is.The research conclusions can provide a guideline to safe operation of restart-up deep-water oil and water pipelines.Near-infrared organic field-effect transistors(NIR OFETs)show great potential in health monitoring and disease diagnosis,and therefore many researchers have been working on NIR OFETs with high sensitivity and high photoresponsivity.Not only high field-effect mobility but also strong NIR absorption is essential for the organic semiconductors in these OFETs.However,there are few organic semiconductors exhibiting both the above attributes.It is a good way to explore the potential of existing materials and to explore new fabrication processes for improving device performance.This paper borrowed the concept of“sensitization”in dye-sensitized solar cells.In NIR OFETs of concern,PBTTT(poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene)film is used as the charge transport layer and a film made from the blend solution of P1(a copolymer of thiophene-fused pyrrolopyrroledione and thiophene)and PC71BM([6,6]-phenyl-C71-butyric acid isomethyl ester)was used as NIR absorbing layer.Finally,vacuum heat bonding technology(lamination)was used to prepare the active layer in NIR OFETs.The results showed that the laminated device could better retain the advantages of each layer.When the channel length was 40μm with lamination temperature of 150℃,the field-effect mobility and the on-off ratio were 0.0078 cm^2 V-1s-1 and 31739 respectively.With illumination of 52.7μW/cm^2 at a wavelength of 850 nm,the photocurrent/dark current ratio reached 113.49 and the photoresponsivity was 0.12 A/W.