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Low specific on-resistance GaN-based vertical heterostructure field effect transistors with nonuniform doping superjunctions 下载免费PDF全文
A novel Ga N-based vertical heterostructure field effect transistor(HFET) with nonuniform doping superjunctions(non-SJ HFET) is proposed and studied by Silvaco-ATLAS,for minimizing the specific on-resistance(R_(on)A) at no expense of breakdown voltage(BV).The feature of non-SJ HFET lies in the nonuniform doping concentration from top to bottom in the n-and p-pillars,which is different from that of the conventional Ga N-based vertical HFET with uniform doping superjunctions(un-SJ HFET).A physically intrinsic mechanism for the nonuniform doping superjunction(non-SJ) to further reduce R_(on)A at no expense of BV is investigated and revealed in detail.The design,related to the structure parameters of non-SJ,is optimized to minimize the R_(on)A on the basis of the same BV as that of un-SJ HFET.Optimized simulation results show that the reduction in R_(on)A depends on the doping concentrations and thickness values of the light and heavy doping parts in non-SJ.The maximum reduction of more than 51% in R_(on)A could be achieved with a BV of 1890 V.These results could demonstrate the superiority of non-SJ HFET in minimizing R_(on)A and provide a useful reference for further developing the Ga N-based vertical HFETs. 相似文献
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利用代谢组学研究大气细颗粒物的生殖毒性效应 总被引:1,自引:0,他引:1
大气细颗粒物(PM2.5)污染已成为严峻的环境问题,探究PM2.5的毒性效应和机理变得尤为重要.本研究利用基于液相色谱/质谱的代谢组学技术,分析经PM2.5悬混液气管滴注暴露后成年雄性大鼠睾丸代谢组的全局变化,采用偏最小二乘判别分析法和非参数检验进行统计分析.结果表明,PM2.5暴露组大鼠睾丸的油提和水提代谢指纹谱均可与对照组实现准确区分,表明PM2.5暴露对大鼠睾丸的整体代谢网络产生了显著影响,最终鉴定出56个差异代谢物.通路分析显示,PM2.5暴露会引起大鼠睾丸的氨基酸和核苷酸代谢紊乱、类固醇激素代谢失衡以及脂类代谢异常,而这些重要通路可能是PM2.5生殖毒性的关键分子事件. 相似文献
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构建含有极化势的静电屏蔽势和单纯的静电屏蔽势这两种原子势模型,应用第二玻恩近似(SBA)理论,分别对激光场中电子-氦原子散射截面进行了理论计算。对比实验结果发现含有极化势的静电屏蔽势给出的结果与实验符合较好。表明极化势在激光辅助电子-原子散射中起着重要作用。 相似文献
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新建HI-13串列加速器辐射防护联锁系统采用PLC自动化控制,增加与优化了原系统的联锁控制逻辑,在充分保证人员辐射安全的同时,使系统状态显示更直观,操作更方便. 相似文献
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Bing Zhang 《中国物理 B》2022,31(5):58503-058503
By using the MOS-based model established in this paper, the physical process of photoelectron generation, transfer, and storage in the four-transistor active pixel sensor (4T-APS) pixels can be simulated in SPICE environment. The variable capacitance characteristics of double junctions in pinned photodiodes (PPDs) and the threshold voltage difference formed by channel nonuniform doping in transfer gates (TGs) are considered with this model. The charge transfer process of photogenerated electrons from PPDs to the floating diffusion (FD) is analyzed, and the function of nonuniform doping of TGs in suppressing charge injection back to PPDs is represented with the model. The optical and electrical characteristics of all devices in the pixel are effectively combined with the model. Moreover, the charge transfer efficiency and the voltage variation in PPD can be described with the model. Compared with the hybrid simulation in TCAD and the Verilog-A simulation in SPICE, this model has higher simulation efficiency and accuracy, respectively. The effectiveness of the MOS-based model is experimentally verified in a 3 μ m test pixel designed in 0.11 μ m CIS process. 相似文献
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钼团簇因具有独特的结构、电子和物理化学性质,被期待在未来的纳米科技中扮演重要角色,但是它们的基态结构至今还存在争议. 本研究采用粒子群优化(CALYPSO)方法对Mon (n=2∽18)团簇的晶体结构进行全局域能量最小化搜索,并结合第一性原理方法进一步优化. 计算表明:当4s和4p半核态不作为价态时,Mon (n=2∽18)团簇有明显的二聚体趋势,原子数为偶数的团簇往往是“幻数”团簇,具有较高的稳定性;但是,将4s和4p电子作为价电子后,平均杂化指数Hsp、Hsd和Hpd显著降低,二聚体趋势急剧减弱. 本文报道了Mon(n=11,14,15)团簇的新基态结构,证明了半核态对于Mon团簇是十分重要的. 相似文献
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基于点击化学和重氮盐法的双共价键固定化方法,制备了一种高灵敏、可重复使用的电化学发光(ECL)适体传感器.该方法以可卡因为分析物,以可卡因适体为分子识别物质,以钌联吡啶衍生物为ECL信号物质.采用电化学方法在玻碳电极表面重氮化叠氮苯胺,通过点击反应连接炔基功能化的钌联吡啶衍生物标记可卡因适体,获得适体传感器.该传感器在共反应剂存在下,产生弱的电化学发光信号,可卡因存在下,电化学发光信号增加.基于此,建立了"信号增强"型检测可卡因的电化学发光分析新方法.电化学发光信号与可卡因浓度在0.1nmol·L~(-1)~100 nmol·L~(-1)范围内呈良好的线性关系,检出限为60 pmol·L~(-1).该传感器具有良好的稳定性,可重复多次使用.该双共价键法在构建ECL传感器方面具有很好的应用前景. 相似文献