聚合物驻极体衰减规律的探索过程

介绍了中国有关驻极体基本规律的探索,取得了一系列原创性公式：驻极体短路TSC的表达式、结晶聚合物中的跳跃电流公式、结晶聚合物驻极体分别在室温段和高温段等温放电的行为方程、ECM的使用寿命及其中的驻极体电阻率的估算。     

驻极体传声器工作电流的分析

最近,新乡市半导体厂曾经先后派有关人员走访（用户）传声器一些生产厂。在相互研究、探讨有关传声器和传声器管等方面的一些质量上的问题时,有的人曾提出：为什么传声器管组装成传声器之后,其工作电流（ＩＤＳ）会变小？与此同时,还提到其它一些类似的问题。确实,传...     

驻极体空间电荷的开路热刺激电流的解析式

用静电感应的理念去探求驻极体空间电荷的开路热激电流（TSC）的起源,用玻耳兹曼能量分配的统计规律导出其解析式。     

驻极体表面电位均匀及同步衰减的条件

关于驻极体表面电位异步衰减的现象，已在很多场合观察到了，但其原因并未得到解释。本文的目的就在于依据新近理论，找出驻极体表面电位均匀且同步衰减的条件。     

结晶聚合物驻极体中的跳跃电流和电荷储存

推导了聚合物和聚合物驻极体中的跳跃电流公式。依据这些公式导出了聚合物驻极体等温放电的理论公式，用驻极体等温衰减的数据估算出电子跳跃的步距约为10^-8m，用X光衍射实验测得的聚合物中结晶区的线度也是10^-8m量极。这从实验上支持上述公式的成立。理论和实验都证明稳态地储存的电荷几乎都被驻极体中的结晶区的能带所俘获。     

驻极体传声器声学特性的分析

本文分析了压强式驻极体传声器内在的物理参数和几何参数对传声器声学特性的影响。通过这些分析,我们可以合理选择有关参数,来设计不同用途的传声器。     

关于近代静电驻极体等温衰减规律的探索——兼及ECM的使用寿命及其驻极体的电阻率的估算

简述了驻极体的起源和历史上对聚合物驻极体等温放电的探索。详述了探索历程,回答了半个多世纪以来驻极体衰减的诸多未解难题。从繁多的实验数据中在人类历史上找到了驻极体等温放电的实验式和ECM中的驻极体在高温中和常温中两个独立的等温放电的行为方程,进而与生产实际相合,近似地建立了估算ECM使用寿命及其中驻极体电阻率的方法和计算式。     

测量传声器驻极体背极的制作及分析

本文介绍了测量传声器中驻极体背极的部分制作技术,并对驻极体材料的性能进行了高温外推测定和分析。在实验基础上,对微型驻极体样品的极化装置进行了改进。本文可供从事传声器生产和研究的有关人员参考。     

驻极体电容传声器温度特性分析和改进对策

着重讨论了驻极体电容传声器的温度特性,分析了影响驻极体电容传声器温度特性的主要因素：振膜、J-FET等对驻极体电容传声器性能的影响,弄清温度特性对这些特性的作用,这对改进工艺,获得稳定的、高性能的传声器有参考意义。另外．还对改善ECM温度特性的对策作了说明。     

电容换能器中的聚合物驻极体表面电位等温衰减解析式及其应用

本文依据驻极体内场推动介质中原有载流子的越垒电流等于驻极体电荷衰减时率的负值的物理过程,导出了电容换能器中聚合物驻极体表面电位等温衰减的解析式。该式与实验结果一致。据此,重建了驻极体高温外推法,解释了迄今为止的诸多驻极体稳定性实验现象。     

用恒流电晕充电改善聚丙烯驻极体的电荷贮存能力

本文通过恒压和恒流充电后的聚丙烯(Polypropyrene简称pp)驻极体的等效表面电位衰减曲线和开路TSD(Thermally Stimulated Discharge)电流谱线的测量,阐明了恒流电晕充电可使聚丙烯驻极体注入较大的体电荷。利用热脉冲技术确定恒流和恒压条件下电荷重心的迁移规律,说明了恒流电晕充电能明显地改善PP电荷的贮存稳定性。     

以半导体为基的薄膜驻极体电荷重心及电荷密度的测量

Ｃ－Ｖ分析法是在半导体技术Ｃ－Ｖ分析法基础上于９０扯代发展起来测量膜厚小于２μｍ且具有ＭＯＳ结构的薄膜驻极体电荷重心及电荷密度的新方法。     

Theoretical and Experimental Investigation of Barrier-Energy-Dependent Charge Injection Mechanisms in Organic Photodetectors

Charge injection is known as the major source of dark current under an applied reverse bias, which directly influences the performance of organic photodetectors with diode architecture. However, it is unclear which of various contributions, such as electron flow through the junction, shunt leakage, thermionic emission, and tunnelling, are dominant. This study investigates the thermionic emission and tunneling models to describe the origin of experimentally measured dark current generated in an organic photodetector. To elucidate the dominant mechanism, the barrier energies at anodic contacts are set from 0.6 to 1.0 eV using photosensitive layers composed of different acceptors. A linear relation is found between the natural logarithm of the dark current density under reverse bias and the square root of the barrier height, which strongly suggests direct tunneling as dominant mechanism for dark current injection. This conclusion is strengthened by temperature dependent dark current analysis. Further knowledge of the dominant mechanism by charge injection can help devise an effective strategy to suppress dark current for effective organic photodetector device implementation.     

聚合物光折变材料聚乙烯咔唑的陷阱态研究

利用热激电流(TSC)技术测量了聚合物光折变材料聚乙烯咔唑(PVK)的退极化电流曲线,获得了热激弛豫过程的活化能。发现聚乙烯咔唑材料的热激退极化电流曲线共有两个峰,低温峰位于338 K,对应的活化能约0.6 eV,高温峰位于417 K,对应的活化能范围在0.53~1.00 eV,在0.77 eV处呈现最大值,陷阱密度极大值为5.7×1013cm-3。同时证明了低温峰是源于偶极子退取向弛豫,高温峰则来自于陷阱中空穴的热释放。     

Identification of Cu-related thermally stimulated current trap in undoped semi-insulating GaAs

In the thermally stimulated current spectra of semi-insulating GaAs, a unique trap T_a at 170K is sometimes observed. The activation energy and capture cross section of T_a are 0.43 eV and 3.7×10⁻¹⁵ cm², respectively. Based on a good correlation with the Cu-related photoluminescence emission at 1.36 eV and the Cu-related deep level transient spectroscopy hole traps HL4 and HB4, we argue that T_a is a Cu-related hole trap.     

Characterization of deep centers in undoped semi-insulating GaAs substrates by normalized thermally stimulated current spectroscopy: Comparison of 100 and 150 mm wafers

A well-established characterization method for investigating deep traps in semi-insulating (SI) GaAs is thermally stimulated current (TSC) spectroscopy; however, TSC is not considered to be a quantitative technique because it involves carrier mobility, lifetime, and geometric factors, which are either unknown or poorly known. In this paper, we first show how to quantify a TSC spectrum, by normalizing with infrared (hv = 1.13 eV) photocurrent, and then apply this method (called NTSC) to study the lateral uniformity of the main deep centers across the diameters of undoped SI GaAs wafers. The wafers used in the study include both the standard 100 mm sizes and the new 150 mm variations, and are grown by both the low and high pressure liquid encapsulated Czochralski techniques. The results reveal that the 150 mm wafers have a worse NTSC uniformity for the main traps and a higher degree of compensation, as compared these parameters for the 100 mm wafers. In addition, nonuniformities related to the electric field effects on both the TSC spectrum and the low temperature photocurrent are found in the 150 mm wafer grown by the low pressure technique.     

Role of contacts in characterization of deep traps in semi-insulating GaAs by thermally stimulated current spectroscopy

The role of contacts in characterization of traps in semi-insulating (SI) GaAs by thermally stimulated current (TSC) methods has been demonstrated by comparing alloyed In and soldered In contacts. Alloyed In contacts, which have an ohmic characteristic, assure high sensitivities in both TSC and temperature dependent photocurrent (PC), and both are important for determining the trap concentrations in SI GaAs. On the other hand, soldered In contacts, which act like Schottky barriers, cause a significant reduction of both PC and TSC, particularly at low temperatures, and can lead to a misinterpretation of TSC results.     

锁相环中电荷泵的分析与设计

用SMIC0.18μmCMOS工艺设计了一种改进型电荷泵电路。该电路基本思想是使用电流参考支路和运放来实现充放电电流的高度匹配,改进则基于重复利用运放的考虑。传统结构为了消除电荷共享效应需要一个单位增益运放,而这一设计省去这个运放,简化了设计,同时也能够达到充放电电流的良好匹配。芯片测试结果显示,输出电压在0.4～1.4V的范围内,电荷泵充放电电流约为1.1mA,失配小于2%。