共查询到18条相似文献,搜索用时 140 毫秒
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利用脉冲恢复技术测量了有限宽基区n+-on-p光电二极管中的少子寿命.实验发现,反向恢复时间同正、反向电流的大小有关.从恢复时间ts与IF/IR函数关系提取的少子寿命随着基区厚度与少子扩散长度比值降低而明显增大.在77 K时,采用传统方法脉冲回复技术提取的少子寿命为28 ns,而当考虑短基区效应时,所提取的少子寿命为51 ns.这表明HgCdTe光电二极管的基区厚度与少子扩散长度比值是采用脉冲恢复技术测量少子寿命技术中的一个重要参数.只有当基区厚度大于三倍少子扩散长度时,传统方法中无限基区厚度的假设条件才成立. 相似文献
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介绍了两种测量半导体材料载流子双极迁移率的原理和方法。用载流子漂移实验方法测量了n型Hg1-xCdxTe(x=0.2)材料在80K时的双极迁移率,讨论了测量条件对双极迁移率的影响。 相似文献
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通过传统光电导衰退法和微波反射光电导衰退法两种方法对长波、中波及短波碲镉汞材料进行了载流子寿命测试,并对结果进行了比较。通过对比发现这两种方法测得的中波和短波材料的结果相差不大。但是对于长波材料,载流子寿命测试结果相差比较大,主要是因为长波材料寿命比较小,在相同的光激发条件下和偏流下,光电导灵敏度小,从而导致测出的信号小,在拟合的过程中偏差较大,导致载流子寿命相差较大。另外,用两种方法在同一短波材料的不同区域进行测试,传统光电导衰退法在材料电极附近测试结果明显偏小,电极区载流子寿命不到其他部分的50%。说明传统光电导衰退法测试载流子寿命受电极的影响比较大。 相似文献
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少数载流子寿命是长波红外HgCdTe材料的重要性能参数。从大量实际数据统计中发现长波红外n型HgCdTe材料的液氮温度电阻和室温电阻的比值与材料载流子寿命有定关系,电阻比值在2 ̄6之间有较大的载流子寿命值,而电阻比值大于10的寿命值较小。 相似文献
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采用改进的光致开路电压衰退方法测量了不同组分Hg1-xCd,Te光伏探测器中光生少数载流子寿命。激发光源为脉冲YAG激光泵浦的光学参量产生器/放大器形成的可调谐红外脉冲激光器。为了减小结电容和串联电阻的影响,引入稳态背景光照明。用存储示波器记录pn结两端开路状态下的电压变化。从指数衰退的曲线经拟合得到开路电压的衰退时间常数,认为其反映了碲镉汞pn结中光生载流子的寿命。实验结果表明:四种组分的探测器在液氮温度下其少数载流子寿命值范围在18—407ns之间。 相似文献
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采用红外透射法测n型HgCdTe晶片的组分x.范德堡法测晶片的载流子浓度n0。用实测值x和n0计算出在相同低温热处理条件下不同组分(0.190<x<0.230)的n型HgCdTe晶片77K时本征浓度ni和杂质浓度nd.得到比值nd/ni与组分x的关系曲线。对此曲线分析可知,77K时HgCdTe(0.190<X<0230)并不处于杂质电离饱和区,而是处于过渡区,故不可以将霍耳系数R确定的载流于浓度n0视为杂质浓度nd。 相似文献
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介绍了一种非接触式用于测量少子寿命的微波反射法,并与通常的光电导衰退法进行了比较。 相似文献
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在测试中波碲镉汞光伏器件的瞬态响应时,当激光光斑照射器件表面位置距离光敏面较远时,器件表现为特殊的双峰脉冲响应现象,分析表明出现这种异常双脉冲现象的原因是光敏区内的少子漂移和光敏区外侧向收集的少子扩散有时间上的差异。通过对器件施加反向偏压,脉冲响应随反向偏压的增大由双峰变成单峰的实验结果,验证了少子侧向收集是导致器件形成双峰的主要原因。对第二个峰拟合得到p区的少数载流子寿命。将瞬态响应获得的少子寿命与该p型中波碲镉汞材料的理论计算和光电导衰退法得到的少子寿命相对比,发现三种方式得到的少子寿命随温度的变化趋势基本一致,这说明了可以通过瞬态光响应得到中波碲镉汞器件的少子寿命。 相似文献
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本文在数值分析和实验数据的基础上,提出了用单色光高频光电导衰减法测量硅单晶少子寿命的表面复合修正公式。 相似文献
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P. S. Wijewarnasuriya M. D. Lange S. Sivananthan J. P. Faurie 《Journal of Electronic Materials》1995,24(5):545-549
We have studied the minority-carrier lifetime on intentionally indium-doped (211)B molecular beam epitaxially grown Hg1-xCdxTe epilayers down to 80K with x ≈ 23.0% ± 2.0%. Measured lifetimes were explained by an Auger-limited band-to-band recombination
process in this material even in the extrinsic temperature region. Layers show excellent electron mobilities as high as ≈2
x 105 cm2v-1s-1 at low temperatures. When the layers are compensated with Hg vacancies, results show that the Schockley-Read recombination
process becomes important in addition to the band-to-band processes. From the values of τn0 and τp0 of one sample, the obtained defect level is acceptor-like and is somewhat related to the Hg vacancies. 相似文献
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R. Sewell C. A. Musca J. M. Dell L. Faraone K. Józwikowski A. Rogalski 《Journal of Electronic Materials》2003,32(7):639-645
The steady-state lifetime of photogenerated minority carriers has been investigated in heterostructure HgCdTe devices fabricated
on molecular-beam epitaxy (MBE) grown material. A wider bandgap capping layer (Hg(1−x)Cd(x)Te, x = 0.44) was grown on a narrower bandgap absorbing layer (Hg(1−x)Cd(x)Te, x = 0.32, λco,80K = 4.57 μm) material in an uninterrupted MBE growth to create an abrupt heterointerface. Steady-state lifetime as a function
of temperature over the range 80–300 K was extracted from photoconductive responsivity at an optical wavelength corresponding
to the peak responsivity at that temperature. At 80 K, the photoconductors exhibit a specific detectivity of 4.5 × 1011 cm Hz−1/2W−1 (chopping frequency of 1 kHz). For each measurement temperature, the steady-state excess carrier lifetime determined experimentally
was compared to the theoretical bulk lifetime for material with x = 0.32 and effective n-type doping density of 3.7 × 1014 cm−3. Theoretical calculations of the Auger-1 lifetime based on expressions developed by Pratt et al. were not able to account
for the reduction in lifetime observed at temperatures above 180 K. Two approaches have been attempted to resolve this discrepancy:
A semiempirical expression for Auger lifetime attributed to Meyer et al. was used to fit to the data, with the Auger coefficient
γ as a fitting parameter. However, the resulting Auger coefficient found in this work is more than an order of magnitude higher
than that reported previously. Alternatively, the reduction in effective lifetime above 180 K may be understood as a “loss”
of carriers from the narrow bandgap absorbing layer that are promoted across the potential barrier in the conduction band
into a low lifetime, wider bandgap capping layer. The reduction in lifetime as a function of inverse temperature for temperatures
above 180 K may be fitted by a “cap lifetime” that has an activation energy equal to the change in bandgap across the heterostucture
and scaled by a fitting constant. 相似文献
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脉冲MOS结构少子产生寿命的统一表征 总被引:2,自引:2,他引:0
本文提出了一种采用脉冲MOS结构测量少子产生寿命的统一表征谱方法,此方法基于任何一种收敛弛豫过程均可以转换成一种衰减的指数函数的思想,应用关以样原理获得脉冲MOS结构瞬态电容差值谱,从谱图中我们可以直接得到关于少子产生寿命信息。本文综合了众多脉冲MOS结构测量少子产生寿命的物理模型,分析了不同模型之间的精细差别。 相似文献