有机薄膜晶体管及其在传感器方面的应用

有机薄膜晶体管因其有机材料种类的多样性、简单的制备工艺和柔性兼容性等优点,在有机半导体器件的研究领域中广受关注。介绍了有机薄膜晶体管的研究进展,并进一步分析了有机薄膜晶体管的基本结构、工作原理及电学特性。同时介绍了有机薄膜晶体管作为传感器的发展进程,重点从有机薄膜晶体管作为传感器的敏感性、选择性等方面阐述,对有机薄膜晶体管作为传感器的优势做了详细的介绍。最后分析了有机薄膜晶体管作为传感器的工作机理。     

双异质结结构的双极型有机薄膜晶体管的研制

制备了基于F₁₆CuPc和CuPc的双异质结结构的双极型有机薄膜晶体管。该器件的载流子迁移率是相同工艺制备的F₁₆CuPc和CuPc双层单异质结有机薄膜晶体管器件的4~5倍。同时,该双异质结结构还能调整载流子的阈值电压,减少双层结构对薄膜厚度等工艺条件的苛刻要求。这种双异质结结构为提升双极型有机薄膜晶体管器件的性能提供了一种有效方法。     

喷雾工艺制备的高性能有机光敏薄膜晶体管

以聚3-己基噻吩(P3HT)为有机层、价格低廉的聚甲基丙烯酸甲酯(PMMA)为绝缘层制备了底栅顶接触型结构的有机薄膜晶体管(OTFT)。采用一种新型喷雾工艺来制备器件的有机薄膜层,通过测量有机薄膜晶体管的电学特性,可得出应用喷雾制备的器件有较好的性能。在100 mW/cm2标准模拟太阳光照下,测量基于P3HT的有机薄膜晶体管器源漏电流随时间的变化特性,结果表明基于P3HT的有机光敏薄膜晶体管,不仅具有明显的响应特性,而且具有很好的恢复特性。同时,对比黑暗和光照1,2,4 min下的OTFT特性转移曲线,得到器件的阈值电压随时间的变化曲线。     

喷雾工艺制备的高性能有机光敏薄膜晶体管

以聚3-己基噻吩(P3HT)为有机层、价格低廉的聚甲基丙烯酸甲酯(PMMA)为绝缘层制备了底栅顶接触型结构的有机薄膜晶体管(OTFT)。采用一种新型喷雾工艺来制备器件的有机薄膜层,通过测量有机薄膜晶体管的电学特性,可得出应用喷雾制备的器件有较好的性能。在100 mW/cm2标准模拟太阳光照下,测量基于P3HT的有机薄膜晶体管器源漏电流随时间的变化特性,结果表明基于P3HT的有机光敏薄膜晶体管,不仅具有明显的响应特性,而且具有很好的恢复特性。同时,对比黑暗和光照1,2,4 min下的OTFT特性转移曲线,得到器件的阈值电压随时间的变化曲线。     

氧对IZO低压无结薄膜晶体管稳定性的影响

本文在室温下制备了无结结构的低压氧化铟锌薄膜晶体管, 并研究了氧分压对其稳定性的影响. 氧化铟锌无结薄膜晶体管具有迁移率高、结构新颖等优点, 然而氧化物沟道层易受氧、水分子等影响, 造成稳定性下降. 在室温下, 本文通过改变高纯氧流量制备氧化铟锌透明导电薄膜作为沟道层、源漏电极, 分析了氧压对于氧化物无结薄膜晶体管稳定性的影响. 为使晶体管在低电压(<2 V)下工作, 达到低压驱动效果, 本文采用具有双电层效应和栅电容大的二氧化硅纳米颗粒膜作为栅介质; 通过电学性能测试, 制备的晶体管工作电压仅为1 V、 开关电流比大于10⁶、亚阈值斜率小于100 mV/decade以及场效 应迁移率大于20 cm²/V·s. 实验研究表明, 通氧制备的氧化铟锌薄膜的电阻率会上升, 导致晶体管的阈值电压向正向漂移, 最终使晶体管的工作模式由耗尽型转变为增强型. 关键词： 薄膜晶体管 无结 氧化铟锌 氧分子     

氧化物薄膜晶体管研究进展

氧化物半导体材料因其载流子迁移率高、制备温度低、电学均匀性好、对可见光透明和成本低等优势,被认为是最适合驱动有机发光二极管的薄膜晶体管(TFT)的半导体有源材料之一.目前氧化物TFT已成功地应用在平板显示的驱动背板上.本文从氧化物TFT的历史和发展状况出发,先介绍了氧化物半导体材料及其载流子输运机理,然后详细介绍了氧化物TFT的结构、制备方法以及电学稳定性,接着介绍了近些年来氧化     

基于二维有机无机杂化钙钛矿的薄膜晶体管

三维有机无机杂化钙钛矿因其优异的光电性能被视为光电领域极具前景的材料,但其在湿度环境下的不稳定性成为制约产业化进程的关键因素之一.本文采用一步溶液法成功制备了碘化铅基二维钙钛矿(PEA)₂(MA)_n–1Pb_nI_3n+1 (n=1, 3,6, 20, 30),对钙钛矿的维度及微观结构进行调控,并将其应用作为薄膜晶体管(TFTs)器件的半导体沟道层.实验结果表明,独特的二维层状结构和量子约束效应有效地抑制了器件的环境不稳定性和离子迁移现象, TFTs器件性能得到提高.基于准二维Quasi-2D (n=6)钙钛矿的薄膜晶体管器件空穴迁移率(μ_hole)达到3.9 cm²/(V·s)、阈值电压为1.85 V、开关比高于10⁴.首次提出将准二维有机无机杂化钙钛矿材料应用到薄膜晶体管中,为制备高性能、高稳定性的薄膜晶体管器件提供了新的思路.     

低栅极电压控制下带有phenyltrimethoxysilane单分子自组装层的有机薄膜晶体管场效应特性研究

制作了底栅极顶接触有机薄膜晶体管器件,60 nm的pentacene被用作有源层,120 nm热生长的SiO₂作为栅极绝缘层.通过采用不同自组装修饰材料对器件的有源层与栅极绝缘层之间的界面进行修饰,如octadecyltrichlorosilane （OTS）,phenyltrimethoxysilane （PhTMS）,来比较界面修饰层对器件性能的影响.同时对带有PhTMS修饰层的OTFTs器件低栅极电压调制下的场效应行为及其载流子的传输机理进行研究.结果得到,当|V 关键词： 有机薄膜晶体管 自组装单分子层 场效应迁移率 低栅极调制电压     

低电压有机薄膜晶体管驱动顶发射有机发光二极管的集成像素的研制

研究了有机薄膜晶体管(OTFT)驱动顶发射有机发光二极管(OLED)的集成制备技术。通过减小栅绝缘层的厚度,达到降低OTFT工作电压的目的。OLED采用标准的绿光器件,利用超薄的Al薄膜作为半透明阴极实现顶发射功能。实现了低电压工作的OTFT与顶发射OLED的集成,其中OTFT的阈值电压为2.0 V,饱和场效应迁移率为0.40 cm2·V-1·s-1。基于实验数据,对集成像素的电特性进行了计算分析,在-5~-10 V的栅电压调控下,像素亮度能在50~250 cd/m2的范围内实现线性灰度调控。     

硅薄膜晶体管液晶显示器的发展

在当前迅速发展的液晶显示技术中,薄膜晶体管液晶显示器以其大容量、高清晰度和高品质全真彩色［1］受到人们的广泛青睐.薄膜晶体管液晶显示器的显示质量和整体性能在很大程度上取决于薄膜晶体管性能,薄膜晶体管(TFT)是众多场效应晶体管（FET）中的一种［2］.非晶硅用于制作薄膜晶体管液晶显示器技术的成熟,使非晶体薄膜晶体管液晶显示器在薄膜晶体管液晶显示器的市场中占据了主导地位,而非晶硅薄膜晶体管由于其低迁移率、电导率［3］等性能,严重制约了薄膜晶体管液晶显示器的发展,寻找合适的替代品,追求高迁移率和高电导率一直是     

多层栅介质层有机薄膜晶体管的存储与光响应特性

在真空室内一次性制备了具有多层栅介质层结构的有机薄膜晶体管(OTFTs).结果表明,制备的OTFTs具有电控开关、存储和光敏多重功能特性.分析认为,存储特性归功于器件的结构,采用了分离的CaF2纳米粒子岛作为电荷俘获中心.在光照环境下,观察到了两种不同类型的光响应特性.快速的光响应来自于有源层吸收了能量大于带隙的光子所...     

Laser printing of multi-layered polymer/metal heterostructures for electronic and MEMS devices

A laser forward transfer technique for the simultaneous printing of polymer/metal stacked micro-laminates is introduced. Several different material combinations as well as stacking architectures are presented including single laser pulse deposited dual layer capacitors, three-layer stacks for potentially printing organic thin-film transistors (OTFTs), and photo-definable polymer/metal laminates and free-standing membranes for MEMS based sensors.     

现代航天光学成像遥感器的应用与发展

概述了当前航天光学成像遥感器在对地、对天观测的多个领域的应用现状,给出了国外著名高分辨率商业卫星的性能指标,归纳了在轨和即将发射的太空望远镜的工作参数,展望了以更高的地面分辨率、更宽的地面覆盖和更高成像质量为目标的高性能光学遥感器的发展方向。依托大型光学成像平台的模块化技术和天地一体化设计为代表的综合性光学遥感器,阐述了实现自动识别和在轨参数自动调整的智能型光学成像遥感器的可行性、环境条件和技术要求。总结了目前在航天光学成像遥感器设计中大口径、主动光学波前探测和在轨智能处理等方面的关键技术和实现难题,提出了可实现的研究思路和未来的发展前景。     

Composition influence of SiNx gate insulator fabricated by radio frequency (RF) Magnetron sputtering on characteristics of organic thin-film transistors

To investigate the effect of composition of SiNx on the properties of organic thin-film transistors (OTFTs), we fabricated bottom gate top contact OTFTs devices with different composition SiNx gate insulator. Pentacene based OTFTs with SiNx insulator, prepared using an interface modification process of UV-ozone treatment, exhibited effective mobility of 0.63 cm2/Vs and on/off current ratio of 10⁵. Overall improvement in field-effect mobility, threshold voltage was observed as silicon content in SiNx increases. The results demonstrate that the viability of using SiNx for OTFTs and of UV-ozone treatment could be used to improve the properties of organic thin-film transistors. The dependence of the contact angle on the SiNx film composition is evident for the untreated samples, the contact angle increases as the silicon content in the untreated nitride film increases. In contrast, the rise in contact angle across all samples after surface treatment signifies effective surface modification to promote hydrophobicity of the nitride surface. The hydrophobic surface is needed for the organic semiconductor.     

Analysis and comparison of total resistance models for accurate static modeling of long- and short-channel OTFTs produced with various organic materials

In the present study, long- and short-channel organic thin film transistors (OTFTs) produced with various organic semiconductor materials as active layers were fabricated, characterized, and modeled. Two charge transport models, the Meyer-Neldel rule grain boundary-trapping (MNR-GBT) and variable range-hopping models (VRH), were applied to investigate the total device resistance of different types of OTFTs fabricated with various organic semiconductor materials. A generalized method of assessing the current-voltage characteristics of both short- and long-channel OTFTs fabricated with different materials is also presented. All of the devices are described theoretically in terms of their current-voltage characteristics by considering the total resistance's dependence on the gate voltage, which was calculated by substituting the total resistance into the drain current equation. The calculated and measured total resistance and output current-voltage characteristics of each device are presented. Using the best modeled values for the total resistance, the experimental data of output current-voltage characteristics I_D(V_D) of different kinds of OTFTs are in agreement with those calculated for four different types of OTFTs with long and short channels. The developed model including the total device resistance (according to the Meyer-Neldel rule grain boundary-trapping model) can be applied to long and short-channel devices produced with different materials generalizing all types of OTFTs.     

不同绝缘层上生长的并五苯薄膜及其OTFT器件性能的研究

分别以SiO₂和PMMA为绝缘层材料制备了底栅顶接触结构的OTFT器件,得到以PMMA为绝缘层的器件具有更好的性能,其场效应迁移率为0.207 cm2·Vs-1,开关电流比为4.93×103,阈值电压为-4.3 V;而以SiO₂为绝缘层的器件,其场效应迁移率仅为0.039 cm2·Vs-1,开关电流比为5.98×102,阈值电压为-5.4 V。为分析器件性能差异的原因,测得了SiO₂和PMMA薄膜表面的AFM图谱及其上沉积并五苯薄膜后的AFM和XRD图谱。通过AFM图谱发现PMMA表面较SiO₂表面粗糙度小,其表面粗糙度的均方根值为0.216 nm,而二氧化硅薄膜表面粗糙度的均方根值为1.579 nm;且发现在PMMA上生长的并五苯薄膜的成膜质量优于在SiO₂,具有较大的晶粒尺寸和较少的晶粒间界。通过XRD图谱发现在PMMA上生长的并五苯薄膜具有明显的衍射峰,进一步证明了在PMMA上生长的并五苯薄膜具有更好的结晶状况,将更有利于载流子的传输。     

Effect of molecular structure on bias stress effect in organic thin-film transistors

Two thiophene-phenylene semiconductors, bis(2-phenylethynyl) end-substituted oligothiophenes (diPhAc-nTs, n = 2, 3), were studied as active layers in organic thin film transistors (OTFTs). Structural and electrical properties of such high vacuum evaporated thin films were compared to pentacene. All three oligomers behave as p-type semiconducting layers into OTFTs. In the same preparation and measurement conditions, diPhAc-3T possesses two of incontrovertible attributes of OTFTs for low cost applications, a high air-stable mobility at low substrate temperature (T_sub), i.e. typically 25 °C together with a reduced bias stress effect compared to the well-known pentacene semiconductor. This study brings to light on the role of the molecular structure involved in the active layer in thin-film devices and describes effects as thin film morphology as important parameters when optimizing the structure of OTFTs.     

Influence of thermal treatment on the performance of copper phthalocyanine thin-film transistors

Organic thin-film transistors (OTFTs) with bottom-gate and bottom-contact configuration based on copper phthalocyanines (CuPc) as active layer were fabricated. The performance of CuPc OTFTs was studied before and after thermal treatment on CuPc layer. The values of the threshold voltage before and after thermal treatment are −6.3 and −5.7 V, respectively. The field-effect mobility values in saturation regime of CuPc thin-film transistors before and after thermal treatment are 0.014 cm²/Vs and 0.0068 cm²/Vs, respectively. The experimental results indicate that there is a heavy decay on the mobility of CuPc based OTFTs mostly due to the crystalline morphology change induced by the thermal treatment, and absolute value of the threshold voltage after thermal treatment decreases with the decrease of the CuPc film thickness and the roughness.     

Optimization and improvement of TIPS–pentacene transistors (OTFT) with UV–ozone and chemical treatments using an all-step solution process

We fabricated an organic thin-film transistor (OTFT) using an all-step solution process. The printed layers, in which the electrode (silver), dielectric layer (BaTiO₃–PMMA), source–drain layer, and semiconductor 6,13-Bis(triisopropylsilylethynyl)pentacene(TIPS–pentacene), were optimized using roll-to-roll, an inkjet printer, and drop-casting. After coating the source–drain layer, we applied ultraviolet (UV)–ozone and self-assembled monolayer (SAM) treatments to the composite layer. The OTFTs treated with the UV–ozone and SAM treatments were found to exhibit excellent performance and good properties in comparison to silicon-based OTFTs.