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在多结太阳电池结构中,P型锗单晶片不仅作为衬底,也是整体电池结构中的一个结。在外延生长过程中,需要进行多次异质外延生长,因此,对P型锗单晶片的表面质量提出了更高的要求。通过对P型锗片去蜡技术的研究,提高了锗片表面质量,降低了外延生长过程中雾缺陷的比例。 相似文献
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同质外延层厚度、铝离子注入深度及光刻偏差会导致4H-SiC浮结结势垒肖特基二极管中浮结位置偏离最优值,器件特性变差。通过数值模拟的方法对浮结横向及纵向位置偏差对其电学特性的影响进行了研究。纵向方向,两个梯形电流分布使得通态比电阻随着浮结由主结向下移动而缓慢增加。击穿电压由距离主结3.5μm处的607V增加到5.6μm处的1 030V。随着浮结进一步向下移动,击穿电压急剧下降,最终保持在550V。这个变化趋势可以通过浮结在漂移区中不同纵向位置的电场分布进行解释。横向方向,浮结与主结对准及交叉放置时电场呈周期性分布且非常均匀,浮结均匀的承担了电压,击穿电压较高。浮结横向偏差时,电流导通路径变长,通态比电阻增加。计算结果表明,浮结与主结对准与交叉放置时Baliga品质因子达到了9.8×109 W/cm2,16%高于1.3μm横向偏差时的8.2×109 W/cm2。因此,4H-SiC浮结结势垒肖特基二极管设计时必须考虑工艺偏差对其特性的影响。 相似文献
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提出了一种新结构半导体双波长激光器 ,即用隧道结把两个发射不同波长的激光器结构通过外延生长的方法连接起来。通过计算和设计 ,制备了性能良好的大功率激射的双波长半导体激光器。双波长器件的实际激射波长分别为 95 1 nm和 987nm,为基模激射。器件在 5 3 0 m A直流工作时输出功率达到 5 0 0 m W,斜率效率为1 .3 3 W/A。在 2 A电流时功率达 2 .4W,斜率效率为 1 .3 8W/A;3 A电流时功率达 3 .1 W,斜率效率为 1 .2 1 W/A。 相似文献
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采用离子束辅助固相外延技术,在Ge基片上制备了SiGe/Ge异质结。利用高分辨透射电镜(HRTEM)、能量散射谱(EDX)、喇曼散射谱对SiGe/Ge异质结的形貌、成分和结构等物理性质进行了表征。还利用上述分析手段研究了固相外延温度对SiGe/Ge异质结中SiGe外延层生长的影响。结果表明,低能条件下(30keV)离子注入有利于形成SiGe外延层;通过对SiGe外延层高分辨晶格像的傅立叶分析得出,900℃下进行固相外延能够有效抑制SiGe外延层中点缺陷的生成;而且利用该技术外延生长的SiGe层完全弛豫。 相似文献
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液相外延法生长的PbTe-PbSbTe异质结外延层的失配位错已经用腐蚀坑法进行了研究。沿〈100〉方向平行于异质结的失配位错线密度与予期的值很符合。这表明由于PbTe-PbSnTe之间的晶格失配引起的应变因引入失配位错而完全消除。从腐蚀坑的分布,电子探针分析和计算表明,在外延生长时失配位错分布在由锡自扩散所决定的区域中的异质结附近。 相似文献
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本文采用Lowdin微扰原理改进计算效率的局域密度泛函(LDF)线性Muffin-tin轨道原子球近似(LMTO-ASA)能带从头计算方法,以平均键能Em作参考能级,计算了以闪锌矿结构氯化硼为衬底外延生长金刚石(C/BN)、以C0.5(BN)0.5合金为衬底外延生长金刚石与闪锌矿结构氯化硼(CIBN)、以金刚石为衬底外延生长闪锌矿结构氯化硼(C\BN)和金刚石与氮化硼以平均晶格常数匹配生长(C-BN)等四种不同情况下,宽禁带半导体异质结C/BN的价带偏移△Ev值,结果分别为1.505、1.494、1.38 相似文献
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通过LP-MOVPE研制了实用化的AlGaAs/GaAsHBT材料。采用CCl4作为P型掺杂剂进行基区重掺杂。所作HBT增益为20~35,截止频率fT>50GHz,最大振荡频率fmax>60GHz,X波段功率HBT输出功率大于5W。 相似文献
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用 CCl4 作为掺杂剂 ,进行了掺碳 Al Ga As层的 LP-MOCVD生长 ,并对其掺杂特性进行了研究 ,分析了各生长参数对掺杂的影响 ;研制了碳掺杂 Al Ga As限制层 80 8nm大功率半导体激光器 ;激光器单面连续波输出功率大于 1 W,功率效率为 0 .7W/ A。 相似文献
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利用常压MOCVD技术在较低生长速率下生长出多种GaAs/AlGaAs多量子阱结构材料,利用低温PL谱和TEM对材料结构进行了表征。所得势阱和势垒结构厚度均匀平整,最窄阱宽为1.8nm。本研究表明,低速率(γ≤0.5nm/s)连续生长工艺能够避免杂质在界面富集,优于间断生长工艺,且在掺si n~+-GaAs衬底上所得量子阱发光强度高于掺Cr SI-GaAs衬底上的结果。 相似文献
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The thermochemical etching behavior of GaAs/AlGaAs multilayer structure during laser beam scanning has been studied. The etch
rate changes between GaAs and AlGaAs epilayers as the etching process proceeds through the layered sample. The phenomenon
can be explained by the difference of thermal parameters of the heterojunction interface. The local temperature rise from
laser irradiation has been calculated to investigate etching characteristics for GaAs and AlGaAs. It is concluded that the
good thermal confinement at GaAs/AlGaAs interface produces the wider etch width of GaAs layer than that of AlGaAs layer in
GaAs/AlGaAs multilayer. The maximum etch rate of the GaAs/AlGaAs multilayer was 32.5 μm/sec and the maximum etched width ratio
of GaAs to AlGaAs was 1.7. 相似文献
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AlInGaAs/AlGaAs应变量子阱增益特性研究 总被引:2,自引:0,他引:2
采用Shu Lien Chuang方法计算了AlInGaAs/AlGaAs应变引起价带中重、轻空穴能量变化曲线,在Harrison模型的基础上详细地计算了AlInGaAs/AlGaAs和GaAs/AlGaAs量子阱电子、空穴子能级分布并且进一步研究了这两种材料在不同注入条件下的线性光增益.进一步计算比较可以得出AlInGaAs/AlGaAs应变量子阱光增益特性要优于GaAs/AlGaAs非应变量子阱增益特性,因此AlInGaAs/AlGaAs应变量子阱半导体材料应用于半导体激光器比传统GaAs/AlGaAs材料更具优势. 相似文献
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Giorgio Biasiol Frank Reinhardt Anders Gustafsson Eli Kapon 《Journal of Electronic Materials》1997,26(10):1194-1198
We demonstrate that the formation of GaAs quantum wires on self-limiting AlGaAs grown on V grooves occurs via a transient
increase of the growth rates in a set of different nanofacets. Upon growth of sufficiently thick layers on AlGaAs, the GaAs
surface reaches a self-limiting profile as well, through an equalization of the relative growth rates on these facets. Atomic
force microscopy studies show that the step density in the facets along the groove evolves with GaAs thickness in the same
way as the facets extension, thus suggesting a role of the step distribution in the establishment of the self-limiting profiles.
The self-limiting GaAs groove profile is much broader than the AlGaAs one at corresponding growth temperatures; however, it
can be sharpened down to a radius of curvature of 5 nm for T = 550°C. Under these conditions, GaAs was successfully used as
a barrier material for growing vertical arrays of self-ordered InGaAs wires. 相似文献
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Self-ordering of GaAs/AlGaAs quantum wires grown by organometallic chemical vapor deposition on grooved substrates was studied. The evolution of the surface profile at the corner between two quasi-{111}A planes was evaluated using cross-sectional transmission electron microscopy. The radius of curvature at the corner exhibits a reproducible, self-limiting value of 7.7 ± 0.7 nm, which increases linearly during subsequent growth of GaAs layers and decreases exponentially to its self-limiting value during further growth of AlGaAs layers. This provides the basis for the self-ordering of periodic, vertically stacked arrays of quantum wires with virtually identical shape, size and composition. 相似文献
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E. A. Evropeytsev G. V. Klimko T. A. Komissarova I. V. Sedova S. V. Sorokin S. V. Gronin D. Yu. Kazantsev B. Ya. Ber S. V. Ivanov A. A. Toropov 《Semiconductors》2014,48(1):30-33
The growth of III–V/II–VI:Mn heterostructures with a high hole concentration in the AlGaAs:Be/GaAs/AlGaAs 2D channel situated in the immediate vicinity of the AlGaAs/Zn(Mn)Se heterovalent interface by molecular-beam epitaxy is reported. Despite the decrease in the hole concentration in the GaAs channel upon a decrease in the distance between the channel and the heterovalent interface, the hole concentration reaches a value of 1.5 × 1013 cm?2 at a temperature of 300 K even at the minimum distance of 1.2 nm. Deep profiling by dynamic secondary-ion mass spectrometry confirmed the back diffusion of Mn from ZnMnSe into the III–V part. High hole concentration and the presence of magnetic manganese ions in the GaAs conduction channel determine the interest in the structures as possible objects in which the effect of magnetic ordering in heterogeneous semiconductor systems can be studied. 相似文献