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An InP/InGaAs single heterojunction bipolar transistor(SHBT) with high maximum oscillation frequency (f_(max)) and high cutoff frequency(f_t) is reported.Efforts have been made to maximize f_(max) and f_t simultaneously including optimizing the epitaxial structure,base-collector mesa over-etching and base surface preparation.The measured f_t and f_(max) both reached 185 GHz with an emitter size of 1×20μm~2,which is the highest f_(max) for SHBTs in mainland China.The device is suitable for ultra-high spee... 相似文献
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An InP/InGaAs single heterojunction bipolar transistor (SHBT) with high maximum oscillation frequency (fmax) and high cutoff frequency (ft) is reported. Efforts have been made to maximize fmax and ft simultaneously including optimizing the epitaxial structure, base–collector mesa over-etching and base surface preparation. The measured ft and fmax both reached 185 GHz with an emitter size of 1 × 20 μ m2, which is the highest fmax for SHBTs in mainland China. The device is suitable for ultra-high speed digital circuits and low power analog applications. 相似文献
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在此篇文章中,开发出了适用于工业化生产的氢化非晶亚氧化硅(a-SiOx:H)作为太阳能电池的钝化层的工艺方法。a-SiOx:H钝化层使用PECVD方法,在大概250℃条件下生长,气体由一氧化氮、氦气和硅烷组成。我们又进一步研究了退火对少数载流子寿命和表面复合速率的影响,因为其对太阳能电池的最终效率影响很大。在4•Ω•cm,P型FZ硅片上测试,少数载流子寿命在退火前只有270us,在退火之后可以达到670us,相应的表面复合速率从70 cm/s 降到30 cm/s。光学特性分析发现,和在太阳能电池中经常使用的本征非晶硅钝化层相比,a-SiOx:H在蓝光附近的光的吸收率有很大的下降。本文引入制作a-SiOx:H钝化层的方法成本低、质量高,适合于工业化生产。 相似文献
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本文以广州大坦沙污水厂、沥氵窖污水厂投标项目为例 ,以单位抗力成本方法优选大型污水处理构筑物桩基方案 ,以供相关工程参考借鉴。 相似文献
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主要研究讨论软土地基液化问题与污水处理构筑物抗浮和承载力要求的解决方法,总结设计,施工,检测经验,以利相关工程参考借鉴。 相似文献
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