共查询到16条相似文献,搜索用时 171 毫秒
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介绍了验证PN结伏安关系特性实验的实验原理,并利用绘图软件Origin7.5对实验数据进行处理.结果表明,PN结的扩散电流和两端的正向电压之间满足指数关系.通过与理论公式的比较,准确地测出了玻尔兹曼常数. 相似文献
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介绍了PN结物理特性综合实验原理,利用绘图软件Matlab对实验数据进行曲线拟合,得到了PN结伏安特性函数表达式和PN结正向压降与温度间关系的拟合曲线,计算了常温下玻尔兹曼常数和PN结温度传感器灵敏度及T=0 K时的半导体近似禁带宽度。 相似文献
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对GaN基蓝光发光二极管(LED)正向电压温度特性进行了研究,发现在温度较高时,正向电压随温度的变化系数逐渐减小,直至出现拐点,正向电压随温度的变化系数由负数变为正数.此时若继续升高温度,则正向电压随温度升高迅速增加,并常常伴随有器件失效的现象发生.在小电流情况下,这种现象不很明显,随着电流的增加,现象表现得越来越明显,拐点出现的温度也越来越低,而且温度超过拐点之后,正向电压值增加得更快.通过与相同封装的另一组器件测试结果对比,排除了封装材料玻璃转换温度的影响.分析认为,这一现象的出现是由器件等效串联电阻
关键词:
发光二极管
氮化镓
正向电压
温度系数 相似文献
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实验观察到低温下低掺杂硅 P-N 结的异常现象.在14—25K 的温区里,出现正向伏安特性曲线交叉、击穿电压峰以及当正向注入电流恒定时正向电压随温度变化特性呈现非单调性.对异常现象作了讨论,提出低温下“热”载流子的存在引起杂质碰撞电离可能是产生这些现象的原因. 相似文献
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半导体数码管(或称LED数码管)的基本单元是删结,目前较多采用磷砷化镓做成的PN结,当外加正向电压时,就能发出清晰的光线.发光二极管的工作电压为1.5—3V。工作电流为几毫安到十几毫安,寿命很长.单个PN结可以封装成发光二极管,多个PN结可以按分段式封装成半导体数码管,其管脚排列如图1所示. 相似文献
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应用计算机测定PN结正向压降的温度特性 总被引:3,自引:2,他引:1
采用电热法把待测的PN结放置于温度可连续变化的热源中,利用精确的温度传感器进行温度测量,并利用计算机数据采集技术,直观地再现了PN结正向压降随温度线性变化的整个物理过程,提高了测量的精度. 相似文献
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功率型LED已经越来越多地运用于航空照明领域,迅速准确地获得LED的结温对航空灯具的散热设计显得极为重要。介绍了一种运用小电流K系数测量LED结温的方法。利用了LED半导体芯片的伏安特性,通过构建测量系统获得LED两端瞬间压降值来算出LED的结温。具有获得LED结温快速、准确、非破坏性等特点。 相似文献
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The measured volt-ampere and volt-capacitance characteristics, together with the thermal emf of the point contact, form the basis for a discussion of possible models of the rectifying barrier in a contact between metal and electronic gallium arsenide prior to, and at various stages in, electric forming.Prior to forming, current is rectified at the p-n junction in the surface region of the semiconductor. Contact properties do not depend on the metal used. The initial forming pulses destroy the surface film and produce either a Schottky barrier or an abrupt microalloy-type p-n junction. As the forming current increases, diffusion processes play an ever greater role, and a p-n junction with smoothly distributed impurities is created. 相似文献
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介绍了验证PN结伏安关系特性实验的实验原理,对实验测得的数据进行处理,给出了测量公式和最后结果数据,提供程序界面、源代码。 相似文献
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K.H. Lee 《Solid State Communications》2005,135(3):162-165
We have studied numerically a rectifying effect in an underdamped Josephson junction ratchet array driven by dc and ac current. The array consists of both alternating potential barriers and alternating inter-capacitances along the direction of vortex flow. The guide banks of high critical currents are assigned for all the longitudinal junctions to prevent the percolative pattern of vortex motion. In some junction parameters, we see a rectifying effect which indicates a finite value of the time-averaged voltage at zero dc bias. The directional dependence of the vortex motion becomes fairly large when the junction parameters lie in an optimal range which gives rise to a Shapiro step at zero dc bias. Such a rectifying effect survives for small thermal fluctuation, but eventually disappear beyond a certain critical temperature. 相似文献
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I. Puica V. Popescu P. Mazzetti A. Stepanescu Gh. Ciobanu 《Physica C: Superconductivity and its Applications》1997,290(3-4):303-310
The 1/f voltage noise in bulk polycrystalline high-temperature superconductors (HTSC) under bias current and magnetic field has its origin in the noise current-dependence of the grain boundary junctions (GBJs), due in turn to the correlated effects of junction critical current and normal resistance fluctuations. The analogy between the results obtained by varying the bias current through the specimen and those performed with temperature as variable is evidenced. The noise maxima obtained in both sets of measurements turn out to be caused by the junction critical current fluctuations, which dominate when the currents flowing through the GBJs are close to the Josephson critical current. The anti-phase correlation between the normal resistance and the critical current fluctuations is responsible for the monotonical decrease of the noise at constant bias current, with the temperature exceeding the value corresponding to the noise maximum. In contrast, varying the bias current at fixed temperature, the voltage noise exhibits a local minimum followed by an increasing tendency after passing through the maximum. 相似文献
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PN结正向电压与温度关系实验中的实际问题 总被引:1,自引:0,他引:1
本文就PN结正向电压与温度关系研究实验中所涉及的常见问题进行了阐述,并提出了相应解决办法。本文能为相关实验工作者提供参考。 相似文献