Effects of P3HT concentration on the performance of organic field effect transistors

Top-contact organic field effect transistors(OFETs) based on poly(3-hexylthiophene)(P3HT) with different concentrations in chloroform(CHCl3) are fabricated.The output characteristics indicate that the P3HT concentration has significant influence on the OFET devices.The performance of the devices firstly is enhanced with increasing the P3HT concentration,and then decreases.The optimized devices with the P3HT concentration of 2 mg/mL show the best performance.The fieldeffect mobility is up to 1.4×10-2 cm2/Vs,...     

Research of organic field effect transistors based on semiconducting single-walled carbon nanotubes

The metal-conducting single-walled carbon nanotubes(m-SWNTs)with small diameters(0.7 nm-1.1 nm)are selectively removed from the single-walled carbon nanotubes(SWNTs)by using HNO 3 /H 2 SO 4 mixed solution.Semiconducting single-walled carbon nanotubes(s-SWNTs)can be separated efficiently from the SWNTs with high controllability and purity based on this novel method,and the outcome is characterized by Raman spectrum.Moreover,the organic field effect transistors(OFETs)are fabricated based on the poly(3-hexylthiophene-2,5-diyl)(P3HT),and untreated SWNTs and separated SWNTs(s-SWNTs)are mixed with P3HT,respectively.It could be found that the P3HT/s-SWNT device exhibits a better field effect characteristic compared with the P3HT device.The current on/off ratio is increased by 4 times,the threshold voltage is also increased from-28 V to-22 V,and the mobility is increased from 3×10-3 cm2/Vs to 5×10-3 cm2/Vs.     

密码体系的安全性

目前,信息的安全问题日益突出,相关产品众多。评测此类产品的质量,对于完善产品的质量,保证信息的安全性至关重要。本文从分析针对安全的攻击模式入手,提出了安全系统设计的要素,为相关产品的评测提供了依据。     

双模式太阳跟踪器太阳质心提取算法

在传统太阳跟踪器的基础上结合图像处理技术,搭建一套双模式太阳跟踪器,并围绕太阳质心提取算法展开研究。针对太阳跟踪器在太阳被云雾遮挡时无法准确跟踪的问题,提出了一种基于快速中值滤波的去雾算法,根据暗通道先验计算出透射率图,使用快速中值滤波代替软抠图方法对透射率图进行平滑,还原出无雾图像。为避免人工阈值带来的分割误差,在去雾增强的图像上使用快速最大稳定极值区域(MSER)特征区域检测方法检测出太阳区域,并提取出太阳质心。实验证明该算法在雾霾天气下仍然能够还原出清晰的太阳图像,准确提取出太阳质心,并且算法复杂度较低,满足太阳跟踪器实时处理的需求。     

有机场效应晶体管输出特性的衰变与恢复

制作了以并五苯作为有源层的有机场效应晶体管（OFETs）。实验观察表明,在原位条件下,器件有很好的输出特性曲线;但在空气中放置3个月后,输出特性曲线明显衰退,并且关态电流增大;为恢复器件性能,在真空条件下,对器件进行加热处理。实验结果表明,经过热处理的晶体管输出特性极大改善。因此,真空热处理可以使衰退器件的输出特性得到...