共查询到14条相似文献,搜索用时 62 毫秒
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利用正向交流(ac)小信号方法对发光二极管(LED)的电容-电压特性进行测量,可以观察到发光二极管中的负电容现象。首次提出测量到的负电容现象是表象,不存在负电容;首次提出发光二极管P-N结的结电容在特定的正向电压范围内等效于可变电容,特定参数的可变电容使电流的相位移相π,使得在测量中表现为负电容。 相似文献
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通过自建装置精确测试了发光二极管(LED)的低频(小于102Hz)电学特性。电学测量表明,所有LED在低频下都表现出明显的负电容(NC)现象,且频率越低NC现象越明显。调制发光测量表明,相对发光强度在低频下表现出明显饱和现象,并且随频率增加而减小。比较电学和光学的测量结果可以证实,辐射发光是产生NC现象的主要原因。通过对LED电学测量结果的详细分析得出了NC随电压和频率的变化关系式。 相似文献
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负阻发光二极管是一种p-n-p-n四层结构的半导体发光器件.它具有负阻特性,故其有开关特性.硅四层结构器件如接成三端形式,便是可控硅器件.如果发光二极管所用的晶体做成两端p-n-p-n器件,就可获得负阻特性并在通态发光.以下,介绍其结构原理及应用. 相似文献
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半导体GaN基蓝光发光二极管的精确电学特性 总被引:1,自引:5,他引:1
对传统的电容-电压(C-V)、电流 -电压(I-V)测量方法和我们自建的表征方法测量得到的蓝光发光二极管(L ED)正向特性的结 果做了详细的对比分析,发现传统测量方法得到的电学参量是不够精确的。但是传统C-V方法得到的表观电容以及我们自建方法得到的结电容在大电压和低 频率下都表现出了明显的负值,该实验结果与经典肖克莱理论相冲突。此外,我们精确 地得到了负的结电容以及结电导随电压和频率变化的经验表达式。这将为半导体二极管的正 向电学特性的理论研究提供实验基础。 相似文献
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随着微电子技术进入纳米领域,功耗成为制约技术发展的主要因素,因此,低功耗器件成为半导体器件领域的研究热点。负电容场效应晶体管基于铁电材料的负电容效应可有效地降低器件的亚阈值摆幅,从而降低器件的功耗。该文设计了一种基于绝缘体上硅(SOI)结构的铁电负电容场效应晶体管,利用TCAD Sentaurus仿真工具对负电容晶体管进行仿真研究,得到了亚阈值摆幅为30.931 mV/dec的负电容场效应晶体管的器件结构和参数。最后仿真研究了铁电层厚度、等效栅氧化层厚度对负电容场效应晶体管亚阈值特性的影响。 相似文献
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Michael Hoffmann Milan Pešić Korok Chatterjee Asif I. Khan Sayeef Salahuddin Stefan Slesazeck Uwe Schroeder Thomas Mikolajick 《Advanced functional materials》2016,26(47):8643-8649
To further reduce the power dissipation in nanoscale transistors, the fundamental limit posed by the Boltzmann distribution of electrons has to be overcome. Stabilization of negative capacitance in a ferroelectric gate insulator can be used to achieve this by boosting the transistor gate voltage. Up to now, negative capacitance is only directly observed in polymer and perovskite ferroelectrics, which are incompatible with semiconductor manufacturing. Recently discovered HfO2‐based ferroelectrics, on the other hand, are ideally suited for this application because of their high scalability and semiconductor process compatibility. Here, for the first time, a direct measurement of negative capacitance in polycrystalline HfO2‐based thin films is reported. Decreasing voltage with increasing charge transients are observed in 18 and 27 nm thin Gd:HfO2 capacitors in series with an external resistor. Furthermore, a multigrain Landau–Khalatnikov model is developed to successfully simulate this transient behavior in polycrystalline ferroelectrics with nucleation limited switching dynamics. Structural requirements for negative capacitance in such materials are discussed. These results demonstrate that negative capacitance effects are not limited to epitaxial ferroelectrics, thus significantly extending the range of potential applications. 相似文献
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Pavan Pujar Haewon Cho Srinivas Gandla Muhammad Naqi Seongin Hong Sunkook Kim 《Advanced functional materials》2021,31(43):2103748
The fabrication of Hf0.5Zr0.5O2-ferroelectric negative capacitor using solution combustion is presented for the first time. The starting materials used for the solution combustion to form equimolar Hf0.5Zr0.5O2 are to act as both combustible elements and cation sources. Jain's method, which is used for estimating the stoichiometric quantities of precursors in propellant chemistry, has also been modified and applied. The conventional assumption for this method that molecular oxygen does not take part in the reaction is refuted and stoichiometric combustion in the presence of molecular oxygen is proposed. This reaction is followed by post-rapid thermal processing to stabilize the metastable, non-centrosymmetric orthorhombic phase. The thin film stacks, Hf0.5Zr0.5O2/HfO2, are used to achieve sub-thermionic swing (forward sweep: 25.42 ± 8.05 mV dec−1, reverse sweep: 42.56 ± 4.87 mV dec−1) in MoS2 negative capacitance field effect transistors with a hysteresis of ≈ 40 mV at 1 nA, resulting in ultra-low-power operation. 相似文献
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变容二极管C-V特性的控制技术 总被引:1,自引:0,他引:1
本文针对变容二极管生产难点:C-V曲线的控制,在理论上分析了PN结纵横向结构对PN结C-V特性、串联电阻、反向电流的影响,得出了适当减小芯片面积,调高杂质浓度可以不增大串联电阻而减小反向电流、改善C-V特性的结论,并应用于生产。 相似文献