共查询到18条相似文献,搜索用时 140 毫秒
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在研制硅光敏器件的十多年中,我们注意到两点:一是硅光敏器件的成品率不够高;二是无法用它们探测微弱的光,即它们的信噪比较小.这两点是由同一原因引起的,那就是它们的暗电流偏大. 结型光敏器件的原理是基于描述p-n结光电特性的位移近似公式[1]:式中IL 为输出的信号电流,I.c为p-n结的短路电流,Ic是p-n结的反向饱和电流,V为加在p-n结上的电压(光生电压或外加的电压),q为电量,k为玻耳兹曼常数,T为温度.光敏二极管(用于光伏效应器件时除外)、光敏三极管和达林顿光敏管都是使接受入射光的p-n结(以下简称为受光p-n结)处于反向偏压下工作,即V《… 相似文献
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自从晶体管问世之后,人们就注意到p-n结的温度特性,随着温度的升高,p-n结反向电流加大,正向压降减小,它是引起晶体管电路温度漂移的主要原因.从五十年代到现在,人们一直在从器件与线路两个方面努力克服这种影响.另一方面,一切与温度有关的物理过程又都可以利用来测量温度.利用p-n结测温,从六十年代开始引起了人们的兴趣[1],七十年代逐渐在一些测量控制系统中获得应用.由于它兼有热敏电阻、热电偶和铂电阻的某些优点:线性度好、灵敏度高、输出阻抗低、温度范围较宽,正在发展成为一门新的测温技术.本文将从p-n结中的物理过程分析这种温度传感… 相似文献
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半导体三极管在饱和区工作时,其等效电路可以用一个三极管及一个由集电极及基极构成的二极管联成的电路表示出来,其中三极管在有源区工作,而二极管在正向偏压下工作。这样的等效电路具有比较明显的物理意义。利用这个电路来求漂移管在一个共基极电路中脉冲工作下的储存时间。解出非平衡少数载流子的连续性方程,求出二极管p-n结附近非平衡少数载流子密度的稳定态分量及暂态分量,从而得到决定储存时间的方程。计算结果表明,储存时间与基极区域及集电极区域中非平衡载流子的寿命及表面复合速度有关。减少寿命及增加表面复合速度就可以减少储存时间。 相似文献
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利用正向交流(ac)小信号方法对GaN发光二极管的电容-电压特性进行测量,可以观察到GaN发光二极管中的负电容现象。正向偏压越大,测试频率越低,负电容现象越明显。测量到的负电容现象是表象,不存在负电容;提出GaN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。分析可变电容对正向交流小信号响应得到:特定参数的可变电容使结电容电流相位落后于交流小信号电压相位π/2,使得在测量中表现为负电容。发现表观电容-正向电压曲线的极值点与理论模型相吻合,证明了该理论模型的正确性。 相似文献
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We consider the excess mechanical stresses induced in semiconductor devices when an external pressure is applied near a p-n junction. The excess stresses are calculated for a p-n tunnel diode under hydrostatic pressure. It is found that these stresses significantly influence the pressure dependence of the peak current in GaAs tunnel diodes. The hysteresis in the peak current is caused by a displacement of electrode material in the neighborhood of the contact.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 60–63, April, 1976. 相似文献
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We realize p- and n-type doping of the organic semiconductor zinc-phthalocyanine using a novel strong organic donor. This allows us to demonstrate the first stable and reproducible organic p-n homojunctions. The diodes show very high built-in potentials, attractive, e.g., for organic solar cells. However, the diode characteristics cannot be described by the standard Shockley theory of the p-n junction since the ideality factor strongly increases with decreasing temperature. We show that this behavior can be explained by deviations from the Einstein relation for disordered materials. 相似文献
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This paper proposes a novel super junction (SJ) SiGe switching power
diode which has a columnar structure of alternating p- and
n- doped pillar substituting conventional n- base region
and has far thinner strained SiGe p+ layer to overcome the
drawbacks of existing Si switching power diode. The SJ SiGe diode
can achieve low specific on-resistance, high breakdown voltages and
fast switching speed. The results indicate that the forward voltage
drop of SJ SiGe diode is much lower than that of conventional Si
power diode when the operating current densities do not exceed
1000 A/cm2, which is very good for getting lower operating
loss. The forward voltage drop of the Si diode is 0.66V whereas that
of the SJ SiGe diode is only 0.52 V at operating current density of
10 A/cm2. The breakdown voltages are 203 V for the former and
235 V for the latter. Compared with the conventional Si power diode,
the reverse recovery time of SJ SiGe diode with 20 per cent Ge
content is shortened by above a half and the peak reverse current is
reduced by over 15%. The SJ SiGe diode can remarkably improve the
characteristics of power diode by combining the merits of both SJ
structure and SiGe material. 相似文献
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利用直流电源对发光二极管(LED)的结电容充电,切断直流电源后对LED的电压-时间特性进行测量。当充电电压低于LED复合发光的门槛电压,LED的电压-时间特性与普通二极管的相似。当充电电压高于LED复合发光的门槛电压,首次观察到:开始放电的瞬间会出现一个快速下降过程,快速下降到门槛电压以下;LED上的电压越高,快速下降到的电压越低。对该现象进行分析,得到一些新的结论。当LED的正偏电压高于复合发光的门槛电压后,出现了注入到扩散区的非平衡载流子随正偏电压的提高而减小的现象,即dQ/du<0。 相似文献
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针对快前沿高重频脉冲的应用需求,设计并研制了一种基于半绝缘砷化镓(SI-GaAs)材料的新型脉冲压缩二极管,通过实验对其压缩性能和重频运行能力进行了测试。实验结果表明,利用此开关能够将前级脉冲的上升沿压缩约270倍和脉宽压缩14倍;并在50 Ω负载上,获得脉冲幅度1.3 kV、上升沿约1.6 ns、脉宽40.59 ns的电脉冲,重复频率达1 kHz,总计运行47 min,触发约两百万次。为研究脉冲压缩二极管的工作原理,对其静态伏安特性进行测试。分析认为,在电压初步加载阶段,SI-GaAs材料内的电场增强型的俘获与离化机制导致耐压增强,二极管在实验过程中出现延迟击穿现象;逆向偶极畴效应产生牵引机制,引发快速上升的位移电流,进而导致反偏结雪崩击穿,二极管表现出瞬间负阻特性,在负载上输出高压纳秒电脉冲。新型脉冲压缩二极管无外加触发快脉冲的前级器件,自身可以维持一定时间的强烈雪崩击穿状态,因此具有体积小、生产成本低的优点,可用于制作小型化高重频的纳秒脉冲功率源。 相似文献
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采用电化学氧化聚合染料增感方法,利用有机染料直接耐晒翠兰对太阳电池顶区材料聚苯胺进行了有机染料增感研究,制备出了Al栅/DS-PAn/n-Si/Al结构的染料增感聚苯胺/硅异质结太阳电池.研究表明,染料增感可使聚苯胺在光照射下光生载流子明显增强,较大幅度地改善聚苯胺的可见光谱响应;J-V特性表明,电池二极管的曲线因子约为6.3,p-n结的潜在势垒高度为0.89 eV;与未增感的PAn/n-Si异质结太阳电池相比,染料增感的DS-PAn/n-Si异质结太阳电池的短路电流和转换效率得到了较大提高,在37.2 W/m2的光照射下,经染料增感的电池短路电流较增感前提高了约6倍,填充因子可达57%,转换效率达1.42%. 相似文献
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《Current Applied Physics》2015,15(4):504-510
Temperature dependence of the lifetime of nonequilibrium charge carriers limited by recombination process in a p-n junction space-charge region has been obtained from current–voltage, capacitance–voltage and thermometric characteristics of GaP p+-n junctions in the temperature range 150–500 K. The results have been refined using the data of the junction relaxation characteristics. Parameters of the carriers' lifetime sensitivity to the temperature and current have been determined. It has been established that the charge carriers recombine predominantly through deep single-level amphoteric-type centres. The depth of the centres makes approx. (EC-1.25 eV). We suppose that the nature of the centres formation is not connected with the junction fabrication technology. It has rather fundamental origin. The results of the present investigation could be used in the development of devices based on wide bandgap semiconductors and particularly high temperature diode sensors. 相似文献