InxGa1—xAs／AlyGa1—yAs多量子阱的高压光致发光研究

用金刚石对顶砧压力装置在浓氮温度下和０～４ＧＰａ的压力范围内测量了不同阱宽（１．７～１１．０ｎｍ）的ＩｎｘＧａ１－ｘＡｓ／ＡｌｙＧａ１－ｙＡｓ（ｘ，ｙ＝０．１５，０；０．１５，０．３３；０，０．３３）多量子阱的静压光致发光谱，发现在Ｉｎ０．１５Ｇａ０．８５Ａｓ／ＧａＡｓ多量子阱中导带第一子带到重空穴第一子带间激子跃迁产生的光致发光峰能量的压力系数随阱宽的增加而减小，在Ｉｎ０．１５Ｇａ０．８５Ａｓ／     

气态源分子束外延InP和InAs基Ⅲ－Ⅴ族化合物材料

本文简要报告我们气态源分子束外延实验结果．材料是ＧａＡｓ（１００）衬底上外延的晶格匹配的Ｉｎｙ（Ｇａ１－ｘＡｌｘ）１－ｙＰ（ｘ＝０～１，ｙ＝０．５），ＩｎＧａＰ／ＩｎＡｌＰ多量子阱；在ＩｎＰ（１００）衬底上外延的ＩｎＰ，晶格匹配的ＩｎＧａＡｓ、ＩｎＡｌＡｓ以及ＩｎＰ／ＩｎＧａＡｓ、ＩｎＰ／ＩｎＡｓＰ多量子阱，ＩｎＧａＡｓ／ＩｎＡｌＡＳＨＥＭＴ等．外延实验是用国产第一台化学束外延（ＣＢＥ）系统做的．     

压变应In0.63Ga0.37As／InP单量子阱的变温光致发光研究

我们对用ＧＳＭＢＥ技术生长的Ｉｎ０．６３Ｇａ０．３７Ａｓ／ＩｎＰ压应变单单量子阱样品进行了变温光致发光研究，Ｉｎ０．６３Ｇａ０．３７Ａｓ阱宽为１ｎｍ到１１ｎｍ，温度变化范围为１０Ｋ到３００Ｋ，发现不同阱宽的压变变量子 激子跃迁能量随温度的变化关系与体Ｉｎ０．５３Ｇａ０．４７Ａｓ材料相似，温度系数与阱宽无关，对１ｎｍ的阱，我们观察到其光致发光谱峰为双峰，经分析表明，双峰结构由量了阱界面起伏一个分子单     

GaAs／Al_xGa_（1－x）As多量子阱红外焦平面性能初探

ＧａＡｓ／Ａｌ＿ｘＧａ＿（１－ｘ）Ａｓ多量子阱红外焦平面性能初探周士源（南京理工大学南京２１００９４）热电流和量子效率是ＧａＡｓ／Ａｌ＿ｘＧａ＿（１－ｘ）Ａｓ多量子阱红外焦平面的两个最关键的特性，它决定着焦平面阵列的探测率和噪声等效温差ＮＥＴＤ。本文...     

Ⅲ族锢源对LP－MOVPE方法生长In_（1－x）Ga_xAs材料的影响

本文报道了利用低压金属有机物汽相外延（ＬＰ－ＭＯＶＰＥ）技术，在（００１）ＩｎＰ衬底上生长Ｉｎ_（１－ｘ）Ｇａ_ｘＡｓ体材料及Ｉｎ_（１－ｘ）Ｇａ_ｘＡｓ／ＩｎＰ量子阶结构材料的结果．对于ＴＭＧ／ＴＥＩｎ源，Ｉｎ_（１－ｘ）Ｇａ_ｘＡｓ材料的非故意掺杂载流子依匿为７．２×１０１６ｃｍ－３，最窄光致发光峰值半宽为１８．９ｍｅＶ，转靶Ｘ光衍射仪对量子阶结构材料测到±２级卫星峰；而对于ＴＭＧ／ＴＭＩｎ源，非故意掺杂载流于浓度为３．１×１０￣１５ｃｍ￣（－３），最窄光致发光峰值半宽为８．９ｍｅＶ，转靶Ｘ光衍射仪对量子阶     

InAs／GaAs亚单层结构的静压光谱研究

在１５Ｋ下测量了ＩｎＡｓ／ＧａＡｓ亚单层结构的静压光致发光，静压范围为０～８ＧＰａ．常压下ＩｎＡｓ层中重空穴激子的发光峰随ＩｎＡｓ层厚的减小向高能移动，同时峰宽变窄，强度减小．其压力行为与ＧａＡｓ基体的基本一致，表明量子阱（线、点）模型仍适用于ＩｎＡｓ／ＧａＡｓ亚单层结构．得到平均厚度为１／３单分子层的样品中由于附加的横向限制效应引起的电子和空穴束缚能的增加分别为２３和４２ｍｅＶ     

3～5.3μmIn_xGa_(1-x)As/Al_yGa_(1-y)As/Al_zGa_(1-z)As非对称台阶量子阱红外探测器

本文报道我们率先研制出的３～５．３μｍＩｎｘＧａ１－ｘＡｓ／ＡｌｙＧａ１－ｙＡｓ／ＡｌｚＧａ１－ｚＡｓ非对称台阶量子阱红外探测器的制备和性能．该探测器具有光伏特征，７７Ｋ温度、±７Ｖ外偏压下的５００Ｋ黑体探测率达到约１．０×１０１０ｃｍ·Ｈｚ１／２／Ｗ，并且，与１→２子带间跃迁相对应的光电流峰值响应波长可随外偏压在中红外（３～５．３μｍ）波段作适当调谐．运用平面波展开法，依据样品的阱、垒结构参数，计算了ＩｎｘＧａ１－ｘＡｓ／ＡｌｙＧａ１－ｙＡｓ／ＡｌｚＧａ１－ｚＡｓ非对称台阶量子阱１→２子带间跃迁的Ｓｔａ     

InGaAsP及其量子阱结构的LP－MOCVD

报道了用低压金属有机化学汽相淀积（ＬＰ－ＭＯＣＶＤ）技术在（１００）ＩｎＰ衬底上生长ＩｎＧａＡｓＰ体材料及ＩｎＧａＡｓＰ（１．３μｍ）／ＩｎＧａＡｓＰ（１．６μｍ）量子阱结构的生长条件和实验结果。比较了５５０℃和５８０℃两个生长温度下Ｉｎ１－ｘＧａｘＡｓｙＰ１－ｙ体材料及相应量子阱结构的特性，表明在５８０℃生长条件下，晶体具有更好的质量和特性。     

新结构高性能In_（0．3）Ga_（0．7）As／In_（0．29）Al_（0．

新结构高性能Ｉｎ_（０．３）Ｇａ_（０．７）Ａｓ／Ｉｎ_（０．２９）Ａｌ_（０．７１）Ａｓ／ＧａＡｓＨＥＭＴ研究证明，ＩｎＧａＡｓＨＥＭＴ的结构优于ＧａＡｓＭＥＳＦＥＴ和习用的ＡｌＧａＡｓ／ＧａＡｓＨＥＭＴ。在ＧａＡｓ上制备的赝配结构ＨＥＭＴ（ＰＭ－ＨＥ...     

GaAs／Al_xGa_（1－x）As多量子阱红外探测器的光调制光谱研究

运用光调制光谱方法测量了ＧａＡｓ／ＡｌｘＧａ（１－ｘ）Ａｓ多量子阱红外探测器材料的调制反射谱，结果表明光调制光谱可以精确确定阱宽、Ａｌ组分、子带跃迁能量和探测峰值波长等许多重要参数，结合实验结果，采用Ｋｒｏｎｉｇ－Ｐｅｎｎｙ模型对材料能带结构进行了理论计算，与实验结果相符．     

In_(0.15)Ga_(0.85)As/GaAs和GaAs/Al_(0.3)Ga_(0.7)As量子阱的静压下光致发光的对照研究

在77K,0—60kbar范围内对在同一衬底上生长的In_(0.15)Ga_(0.85)As/GaAs和GaAs/Al_(0.3)Ga_(0.7)As量子阱的静压下的光致发光进行了对照研究。在GaAs/Al_(0.3)Ga_(0.7)As量子阱中同时观察到导带到轻重空穴子带的跃迁。而在In_(0.15)Ga_(0.85)As/GaAs阱中只观察到导带到重空穴子带的跃迁。与GaAs/Al_(0.3)Ga_(0.7)As的情况相反,In_(0.15)Ga_(0.85)As/GaAs 量子阱的光致发光峰的压力系数随阱宽的减小而增加。在压力大于48kbar时观察到多个与间接跃迁有关的发光峰,对此进行了简短的讨论。     

In0.15Ga0.85As／GaAs多量子阱子能带跃迁压力效应

用光调制吸收光谱方法在不同压力条件下研究了In_(0.15)Ga_(0.85)As/GaAs应变多量子阱的子能带跃迁,发现子能带跃迁能量随压力的变化行为与构成量子阱的组成体材料带间跃迁能量的变化相似,并且子能带跃迁能量压力系数与量子阱的宽度有关。还讨论了压力可能引起的导带不连续率的变化和In_(0.15) Ga_(0.85)As应变层的临界厚度。     

应变超晶格In_(0.15)Ga_(0.85)As/GaAs的电镜和光谱研究

用光调制反射谱和透射电镜技术研究分子束外延生长的应变超晶格In_(0.15)Ga_(0.85)As/GaAs,并讨论了实验结果。     

In_xGa_(1-x)As/GaAs应变单量子阱结构的静压光致发光研究

在室温和液氮温度下,0-60kbar范围内对In_xGa(1-x)As/GaAs应变单量子阱结构进行了静压光致发光研究.在室温下,量子阱中发光峰随压力的变化是亚线性的,而在液氮温度下是线性的.阱中发光峰的压力系数比GaAs势垒的小约10％左右.发现对应于导带第二子带的发光峰的压力系数略大于第一子带的.此结果与GaAs/Al_xGa_(1-x)As量子阱的情况正好相反.     

Design and Realization of Resonant Tunneling Diodes with New Material Structure

A new material structure with Al0.22Ga0.78As/In0.15Ga0.85As/GaAs emitter spacer layer and GaAs/In0.15Ga0.85As/GaAs well for resonant tunneling diodes is designed and the corresponding device is fabricated.RTDs DC characteristics are measured at room temperature. Peak to valley current ratio and the available current density for RTDs at room temperature are computed.Analysis on these results suggests that adjusting material structure and optimizing fabrication processes will be an effective means to improve the quality of RTDs.     

一种新材料结构的RTD器件的设计及实现

设计了一种带有Al0.22Ga0.78As/In0.15Ga0.85As/GaAs发射极空间层和GaAs/In0.15Ga0.85As/GaAs量子阱的共振隧穿二极管(RTD)材料结构,并且成功地制作了相应的RTD器件.在室温下,测试了RTD器件的直流特性,计算了RTD器件的峰谷电流比和可资电流密度.在分析器件特性的基础上,指出调整材料结构和优化工艺参数将进一步提高RTD器件的性能.     

不同阱宽的In_xGa_(1-X)As/GaAs应变量子阱的压力行为

在77K下测量了不同阱宽(30-160A)的In_xCa_(1-x)As/GaAs应变量子阱的静压下光致发光谱.静压范围为0-60kbar.发现导带第一子带到重空穴第一子带的激子发光峰的压力系数从 160A阱的 9.74meV/kbat增加到 30A 阱的 10.12meV/kbar.计算表明,阱变窄时电子波函数向压力系数较大的势垒层中的逐步扩展是压力系数随阱宽变小而增加的原因之一.在压力超过50kbar后观察到两个与间接跃迁有关的发光峰.     

Photoemission characteristics of transmission-mode negative electron affinity GaAs and (ln,Ga)As vapor-grown structures

Several types of transmission-mode negative electron affinity (NEA) photocathodes were investigated. The first group consisted of GaAs cathodes of various thicknesses grown on a composite structure composed of a GaP substrate and a Ga(As,P) buffer layer. These cathodes were of two types, one having an abrupt Ga(As,P)/GaAs interface and the other having a compositionally graded interface. The latter type exhibited the highest transmission-mode quantum efficiency, 0.11 electron per incident photon at 0.85 μm. It is assumed that the electron diffusion length L in the GaAs layer is limited by misfit dislocations arising from the lattice mismatch between the GaAs and the Ga(As,P) buffer layer. L increased with cathode layer thickness more rapidly for the graded structure, suggesting that misfit dislocation propagation into the GaAs layer is less when the dislocations are generated gradually (graded structure) than when they are introduced abruptly (ungraded structure). The second group of samples consisted of (In, Ga)As alloy cathodes of various compositions grown on both GaAs and GaP substrates with lattice-mismatch-reducing buffer layers of (In, Ga)As, (In, Ga)P, and Ga(As,P). It was found that photosensitivity was improved significantly by reducing the amount of lattice mismatch between the (In, Ga)As cathode layer and the substrate or buffer layer. Using an (In, Ga)As cathode with an (In,Ga)P buffer layer grown on a GaP substrate, transmission quantum efficiencies in excess of 0.01 were obtained over the relatively broad wavelength range of 0.7 to 1.04 µm.     

Negative differential resistance of GaAs/Al/sub x/Ga/sub 1-x/As multiquantum well structures under high power photoexcitation: structure optimisation for an oscillator

A study is presented of the photocurrent behaviour of p-i-n diodes having GaAs/Al/sub x/Ga/sub 1-x/As MQW absorption regions for varying incident power, incident wavelength and barrier height, given by the Al fraction x. Optimum results for applications in high power oscillators are expected to be obtained for 0.1>     

大功率In(Ga)As/GaAs量子点激光器

利用分子束外延技术和 S- K生长模式 ,系统研究了 In As/Ga As材料体系应变自组装量子点的形成和演化 .研制出激射波长λ≈ 960 nm,条宽 1 0 0μm,腔长 80 0μm的 In( Ga) As/Ga As量子点激光器 :室温连续输出功率大于 3.5W,室温阈值电流密度 2 1 8A/cm2 ,0 .61 W室温连续工作寿命超过 3760小时