Optoelectronic characteristics of InGaAs (P)/InP strained quantum well and superlattice

利用低压金属有机化合物化学汽相沉积（MOCVd）生长技术在InP衬底上生长IngAAS/InP应变量子阱、超晶格和IngAASP/InP量子阱结构材料，利用77k光荧光（Pl）测量这一应变量子阱和量子阱的光学性质，利用双晶X光测量应变超晶格的性质。InGaAs/InP strained quantum well and superlattice,and InGaAsP quantum well were grown on InP substrate by low-pressure metal organic vapor deposition (LP-MOCVD).The optical characteristics of the strained quantum well and quantum well were studied by photoluminescent (PL) at 77 K, while the characteristics of InGaAs/InP strained superlattice are measured by X-ray double crystal diFFraction.福建省自然科学基金;国家自然科学基

Growth and Properties of Ultra Thin GeO_2 by Rapid Thermal Oxidation

超薄氧化锗对钝化gE MOSfET器件中高介电常数栅介质与gE界面具有重要的意义。通过研究400~550℃下快速热氧化锗制备氧化锗的过程及其性质,发现在一定温度下较短的氧化时间内,氧化锗的厚度随氧化时间的增加呈明显的两段线性关系。在开始阶段,氧化锗具有高的生长速率;当氧化锗厚度达到一定值(与温度相关)时,氧化速率变慢,与dEAl-grOVE氧化模型中的线性生长速率基本一致。X射线光电子能谱(XPS)测试结果表明氧化锗中存在不同价态的gE,且随着氧化时间的增加,氧化锗的氧化程度逐渐提高。在550℃下氧化180 S形成的氧化锗用于gE-MOS结构,C-V特性表明在禁带中央处获得了较小的界面态密度,达到1.7x1012 CM-2EV-1。It was demonstrated that the ultra thin germanium oxide was effective to passivate the high-k dielectric/Ge interface for fabrication of high performance germanium MOSFET.The properties of the ultra thin germanium oxide formed by rapid thermal oxidation were investigated which were in temperature range from 400 ℃ to 550 ℃.The two distinct linear relationships between germanium oxide thickness and oxidation time are observed during the initial oxidation of Ge.At the very beginning,the oxidation rate is very high,which is reduced significantly when the oxide thickness reaches a certain value(depending on oxidation temperature).The slower oxidation rate on the later stage is in fair agreement with the prediction of Deal-Grove model.The X-ray photoelectron spectra from the germanium oxide reveals that the various of chemical states of Ge exist in the oxide and the degree of oxidation of Ge increases with oxidation time.The capacitance-voltage characteristics of the Ge MOS structure with germanium oxide fabricated at 550 ℃ for 180 s shows small hysteresis and relatively lower interface state density of 1.7×1012 cm-2eV-1 at midgap.国家重大研究计划项目(2012CB933503);国家自然基金(61036003;61176092;60837001);中央高校基础业务费项目(2010121056

The Characterization of InGaN and InGaN/GaN Quantum Wells Grown by LP-MOCVD

【中文摘要】 利用 MOCVD系统在 Al2 O3衬底上生长 In Ga N材料和 In Ga N/ Ga N量子阱结构材料。研究发现 ,In Ga N材料中 In组份几乎不受 TMG与 TMI的流量比的影响 ,而只与生长温度有关 ,生长温度由 80 0℃降低到 74 0℃ ,In组份的从 0 .2 2增加到 0 .4 5 ;室温 In Ga N光致发光光谱 (PL)峰全半高宽 (FWH M)为 15 .5 nm;In Ga N/ Ga N量子阱区 In Ga N的厚度 2 nm,但光荧光的强度与 10 0 nm厚 In Ga N的体材料相当。 【英文摘要】 InGaN bulk material and InGaN/GaN quantum well were grown by low pressure metal organic chemical vapor deposition(LP MOCVD),and they were characterized by X ray and photo luminescence(PL) maximum at room temperature.The PL full width of half of InGaN grown at 800 ℃ is 15.5 nm at room temperature and the peak wavelength is 437 nm.The In composition in InGaN did not dependent on the ratio of TMG and TMI but on the growth temperature and the In content increases from 0.22 at 800 ℃ to 0.45 at 740 ℃.The In com...福建省自然科学基金资助项目 (E9820001) ; 国家教育部高等学校骨干教师资助计划项目资

The Photoluminescence Properties of Self assembled and Nano sized Silicon Quantum Dots

【中文摘要】 用 Si H4 气体的减压 CVD法 ,在氧化硅以及石英基板上自然形成了高密度的 (～ 10 11cm-2 )纳米尺寸的半球状硅晶粒 (硅量子点 ) ,并且对其光学吸收和发光 (Photo- luminescence,PL)特性进行了评价。用表面热氧化了的硅量子点样品 ,在室温条件且在高于 1.2 e V以上的能量范围内观察到了 PL谱。随着量子点尺寸的减少 ,PL谱的光学吸收限移向高能方向。 PL谱的峰值能呈现大幅度的 (约 0 .9e V)斯塔克移动 ,并且 PL谱的强度几乎与温度无关 ,说明发光来自与局域能级相关联的发光和复合过程。 【英文摘要】 Using the low pressure CVD method with SiH 4 gas, we have accumulated the silicon quantum dots in self assembled and nano sized on a silica glass substrate. The optical absorption and photoluminescene spectra have been observed. With decreasing the size of silicon quantum dot, the limit of optical absorption shifts to higher energy. The intensity of photoluminescence spectrum is independent of temperature, which means that the photoluminesce...福建省自然基金资助项

爆生气体作用下孔壁岩石开裂的机理及影响因素研究

开发低渗透油气田最有效的手段是改善低渗透储层物性,但目前常用的水力压裂、酸化和高能气体压裂等措施也各有其不足,因此对岩石具有应力波和爆生气体双重作用的"层内爆炸"方法应运而生。针对爆生气体作用下孔壁岩石的开裂问题,通过分析试验数据,建立了考虑试样惯性的力学模型,并从动力学角度对动态载荷作用下孔壁岩石产生多裂缝的机制做了数值模拟研究。试验及数值模拟结果表明,爆生气体动态载荷作用下孔壁岩石产生多裂缝的实质是试样对动态载荷的结构响应,孔壁岩石能否产生多裂缝主要取决于载荷、约束、结构和材料属性等因素的影响。此外还得到了不同加载速率和初始损伤条件下孔壁岩石开裂的一般规律

Rock damage experiment and evaluation method by exploding wave

通过水中爆炸激波对试样的损伤试验来模拟激波对地层岩石的破坏作用。试验中观测了爆炸后试样内部裂纹形貌的分布，利用自制传感器测到了试样内部的激波压力，优化筛选出了损伤度模型。通过对试样弹性波速进行处理和分析，给出了试样的动态损伤阈值求解方法。结果表明，激波在试样中的传播符合指数衰减规律，相对损伤度、无量纲波速的平方、无量纲拉应力它们两两之间呈线性关系

Optimum design of the well number for InGaAsP/InP SCH QW laser and its fabrication

【中文摘要】 根据对InGaAsP－InP分别限制量子阱激光器结构的注入效率的分析和利用X射线衍射对InGaAsP－InP20个周期的多量子阱结构异质界面的研究，设计、制备了4个阱的InGaAsP－InP分别限制量子阱激光器结构。利用质子轰击制得条形激光器。阈值电流为100mA，直流室温连续工作。单面输出外微分量子效率为36％。 【英文摘要】 Based on the analysis of injection efficiency for InGaAsP/InP SCH - QW laser and the research on X - ray diffraction kinetic simulation, a four - well InGaAsP - InP MQW laser structure is designed and fabricated. A stripe laser under CW operation with threshold as low as 100 mA is also obtained by means of proton implantation with single - side external differential quantum efficiency of 36%.福建省自然科学基金;国家自然科学基

激波作用下岩石损伤试验及评价方法

通过水中爆炸激波对试样的损伤试验来模拟激波对地层岩石的破坏作用。试验中观测了爆炸后试样内部裂纹形貌的分布，利用自制传感器测到了试样内部的激波压力，优化筛选出了损伤度模型。通过对试样弹性波速进行处理和分析，给出了试样的动态损伤阈值求解方法。结果表明，激波在试样中的传播符合指数衰减规律，相对损伤度、无量纲波速的平方、无量纲拉应力它们两两之间呈线性关系

Development for InP MISFET for OEIC

用MOCVD方法生长了n＋－InP/n－InP/SI－InP材料，以HfO2为介质膜，用电子束蒸发和选择化学腐蚀研制成栅宽0.002mm、栅长为0.2mm的具有蘑菇状栅极结构的InPMISFET。直流特性测量表明，跨导gm=80－115ms/mm，开启电压VT－3.62V，沟道的有效电子迁移率ueff=674cm2/V·S，界面态密度NSS=9.56×1011cm－2。设计计算的特征频率fT97.1GHz，最高特征频率fmax64.7GHz，尚未发现器件性能的漂移现象。本器件可作为InP基的单片光电子集成器件(OEIC)的放大部分。A mushroom gate structure InP MISFET was developed by the electron beam evaporation and chosen chemical etching. The device has n＋ － InP/n－ InP/SI－ InP: Three layers structure which made by LP－ MOCVD as matter, has Ti－ Al film as gate electrode, has Ti－ Al/Au－ Ge film as source electrode or drain electrode. The gate dimension is 0.002mm× 0.2 mm. The D C Character shows that the transconductance gm is about 80～ 115 ms/mm, the threshold voltage VT is about － 3.62 V, the channel effective electron mobility is about 674 cm2/V· S, the average electron velocity Va is about 1.22× 107 cm/s, the interface state density Nss is about 9.56× 1011 cm－ 2, The cut－ off frequency fT is about 97.1GHz, the maximum working frequency fmax is about 64.7GHz. Up to now, we have not fought the flotation of device quality. The device can be used in InP substrate OEIC as amplificatory element.国家自然科学基金资助项目!(69486004);; 福建省自然科学基金资助项目!(F97003