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The temperature-dependent electrical and charge transport characteristics of pentacene-based ambipolar thin-film transistors (TFTs) were investigated at temperatures ranging from 77 K to 300 K. At room temperature (RT), the pentacene-based TFTs exhibit balanced and high charge mobility with electron (μe) and hole (μh) mobilities, both at about 1.6 cm2/V s. However, at lower temperatures, higher switch-on voltage of n-channel operations, almost absent n-channel characteristics, and strong temperature dependence of μe indicated that electrons were more difficult to release from opposite-signed carriers than that of holes. We observed that μe and μh both followed an Arrhenius-type temperature dependence and exhibited two regimes with a transition temperature at approximately 210–230 K. At high temperatures, data were explained by a model in which charge transport was limited by a dual-carrier release and recombination process, which is an electric field-assisted thermal-activated procedure. At T < 210 K, the observed activation energy is in agreement with unipolar pentacene-based TFTs, suggesting a common multiple trapping and release process-dominated mechanism. Different temperature-induced characteristics between n- and p-channel operations are outlined, thereby providing important insights into the complexity of observing efficient electron transport in comparison with the hole of ambipolar TFTs. 相似文献
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2,9-DPh-DNTT, an isomeric of diphenyl-dinaphtho[2,3-b:2′,3′-f]-thieno[3,2-b] thiophene (DPh-DNTTs), is an emerging candidate of high mobility organic semiconductor material. In this work, a high performance 2,9-DPh-DNTT organic thin-film transistor (OTFT) is fabricated by the method of weak epitaxy growth. The quality of 2,9-DPh-DNTT thin film was significantly improved when its epitaxial layer grows on an inducing layer of para-sexiphenyl (p-6P). Continuous large-area, highly ordered and terraced 2,9-DPh-DNTT polycrystalline thin films are obtained. The hole mobility of as-fabricated 2,9-DPh-DNTT thin-film transistor reaches up to 6.4 cm2 V−1s−1. This simple process of preparing high mobility 2,9-DPh-DNTT thin-film transistor supplies a facile route of large-area OTFT fabrication. 相似文献
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We investigated the resistive switching characteristics of a polystyrene:ZnO–graphene quantum dots system and its potential application in a one diode-one resistor architecture of an organic memory cell. The log–log I–V plot and the temperature-variable I–V measurements revealed that the switching mechanism in a low-current state is closely related to thermally activated transport. The turn-on process was induced by a space-charge-limited current mechanism resulted from the ZnO–graphene quantum dots acting as charge trap sites, and charge transfer through filamentary path. The memory device with a diode presented a ∼103 ION/IOFF ratio, stable endurance cycles (102 cycles) and retention times (104 s), and uniform cell-to-cell switching. The one diode-one resistor architecture can effectively reduce cross-talk issue and realize a cross bar array as large as ∼3 kbit in the readout margin estimation. Furthermore, a specific word was encoded using the standard ASCII character code. 相似文献
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We report on an organic-based photodetector that integrates a dual-gate organic thin-film transistor (DG-OTFT) with an organic photodiode (OPD) to produce a device with a high effective responsivity at low optical power and video-rate compatible response. In this device, the OPD operates in photovoltaic mode, instead of the commonly used photoconductive mode, to modulate one of the gate voltages of the DG-OTFT. Effective responsivity values of 10 A W−1 are measured at optical power values lower than 10 nW at 635 nm. Modeling of the operation of this new photodetector suggests that effective responsivity values up to 105 A W−1 can be achieved at optical powers of 1 nW using current printing technology and state-of-the-art organic semiconductors. 相似文献
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根据JFET线性区漏源之间沟道电阻受栅源电压控制的机理,推导JFET电流公式,对可变电阻的性能进行了分析。通过PSpice软件仿真了JFTT压控可变电阻,提出了改善JFET可变电阻非线性及扩展电阻动态范围的方法。结合单片机和D/A转换器,利用该方法设计了程控JFET可变电阻,其阻值范围为75.703~141.004Ω,分辨率低于0.025Ω,满足了自动气象站信号模拟器温度通道所需电阻阻值范围80.305~130.894Ω及分辨率低于0.03Ω的要求,为数据采集器温度通道的检定提供标准的可变电阻信号。 相似文献
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采用薄膜分散法制备格列齐特脂质体,以粒径和包封率为考核指标,通过单因素实验和正交实验优化制备条件,测定最优条件制备格列齐特脂质体的平均粒径和包封率。确定最优制备条件为:药脂比1∶10(g∶g)、超声时间10min、成膜温度60℃、缓冲液pH值6。所制备脂质体的平均粒径为(108.3±12.4)nm、包封率为(72.19±3.6)%、平均Zeta电位为(-40.8±2.3)mV,且在4℃下保存稳定性好。电镜照片显示,所制备脂质体圆整度好、粒径均一、无粘连。表明采用薄膜分散法制备格列齐特脂质体工艺稳定,质量可控。 相似文献
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