基于 In$_{{\bf 1}-x}$Ga$_{x}$P 梯度合金核无镉量子点的制备及 LED 应用

低毒性磷化铟量子点(indium phosphide quantum dot, InP QD)作为最有可能取代有毒重金属镉基量子点的材料, 已经在下一代商业显示和照明领域中显示出巨大潜力. 然而, 合成具有高荧光量子产率(photoluminescence quantum yield, PL QY)的InP QD 仍然具有挑战性. 因此, 提出了以乙酰丙酮镓作为镓源, 在高温下通过乙酰丙酮基对表面配体的活化作用, 生成具有梯度合金核的 In$_{1-x}$Ga$_{x}$P/ZnSe/ZnS 量子点, 有效解决了原有的 InP 与 ZnSe 之间晶格失配的问题; 同时减少核壳界面缺陷, 使量子点的荧光量子产率高达 82%, 所制备量子点发光二极管(quantum dot light-emitting diode, QLED)的外量子效率(external quantum efficiency, EQE)达到 3.1%. 相比传统的 InP/ZnSe/ZnS 结构量子点, In$_{1-x}$Ga$_{x}$P/ZnSe/ZnS 量子点荧光量子产率提高了 25%, 器件的外量子效率提高了近一倍. 该方案为解决 InP 量子点荧光量子产率低、发光器件性能差等问题提供了新的思路.     

GaAs/InP异质材料及MESFET器件研究

用低压金属有机气相外延（LP－MOCVD）在InP衬底上生长出较高质量的GaAs材料，并对材料进行Raman、光致发光（PL）谱的测试分析，结果表明在GaAs／InP外延层中存在伸张应力致使Raman的LO模式的频率红移；PL谱峰较强，16K下测到GaAs的特征激子峰和杂质相关的激子峰，表明了GaAs外延层的晶体质量较好。以此生长方法制备了金属－半导体场效应晶体管（MESFET），其单位跨导可达200ms/mm。该器件已经达到GaAs同质结构的器件水平。     

n—Ga1—xAlxAs的电子喇曼散射,束缚声子和DX中心

观测到ｎ－Ｇａ１－ｘＡｌｘＡｓ的束缚声子和电子喇曼散射．对ｎ－Ｇａ１－ｘＡｌｘＡｓ进行喇曼散射实验，揭示了在低温光照条件和组分超过某临界值的合金半导体存在着有效质量型的浅施主能级，引起束缚声子和电子喇曼散射．在较高温度，此能级电子减少到由ＤＸ中心表征的施主深能级．实验结果证实了Ｇａ１－ｘＡｌｘＡｓ的ｎ型杂质具有深－浅双稳特性．根据晶格动力论，浅释了Ｇａ１－ｘＡｌｘＡｓ中施主的电荷态．     

差温生长法制备 1.55 μm InP/InGaAsP/InP 激光晶片

采用差温生长法制备了１．５５μｍＩｎＰ／ＩｎＧａＡｓＰ／ＩｎＰ双异质结激光晶片．差温生长法是在高温（约６２６℃）状态下生长ＩｎＧａＡｓＰ有源层;然后降低温度,在低温（约６００℃）状态下生长Ｐ－ＩｎＰ上限制层．此方法有效地解决了这种结构长波区（λ＞１．４５μｍ）的回熔问题,并克服了其他方法的缺点．     

LP-MOCVD法制备高质量InP薄膜

本文报导以国产三甲基铟(TMIn)和进口的磷烷(PH_3)为源,采用低压金属有机化合物化学气相沉积(LP-MOCVD)方法,在InP衬底上生长高质量InP的工艺条件以及外延层的电学特性和光学特性.     

测量InGaAsP/InP异质界面的化学斜面法

本文利用AES(俄歇电子能谱)测量了InGaAsP/InP异质界面的组分分布和界面宽度,提出了化学斜面法测量界面宽度的新方法.同时讨论了晶格失配对界面宽度的影响.     

GaInP/(Al_xGa_(1-x))InP多量子阱结构的光荧光特性分析

利用金属有机化合物气相沉积(MOCVD)技术生长了GaInP/(AlxGa1-x)InP多量子阱(MQW)结构材料,对其进行光荧光特性测量,观察到在波长λ=647 8nm和λ=861 6nm处分别存在一个强发光锋和一个弱发光峰.理论计算和实测结果基本一致.     

Defects in NTD InP probed by positron annihilation spectroscopy

Two samples of high purity InP extracted from the same wafer were examined by positron annihilation spectrum analysis after having been, processed by means of thermal Neutron Transmutation Doping (NTD). Compared with the as grown sample with an average positron lifetime of 246 ps at 300 K, the high dose doped one has an average lifetime of 251 ps and the lower dose doped one 248 ps measured under the same condition, indicating that some defects have been introduced in the NTD process. Annealing experimental results show a steady decrease in the average lifetime with increasing annealing temperature up to 550°C. And a peak in lifetime curve around 500°C was observed which may be attributed to defects related structure conversion. Temperature experiments conducted on the low dose doped sample from 150K to 290 K suggest the existence of vacancy-impurity complex which have given rise to an abnormal reduction of average lifetime with increasing temperature. Also a n-type InP sample (A61) was irradiated with thermal neutrons in another reactor and the lifetime results display an increase of 15 ps. Furthermore, to study epithermal neutron irradiation effects on InP, measurements were performed on an n-type InP sample (N119) along with one p-type sample (P118) after having been irradiated with high fluence of epithermal neutrons. The former has an average lifetime of 262 ps and the latter 247 ps after irradiation. The results prove that on some occassion epithermal neutrons can produce sizable defects in InP. Foundation item: Supported by the Science Foundation of Hubei Province (203980532) Biography: WEN Xiang-e (1976-), male, Master candidate, Research direction; majar research interest is defects in semiconductor materials using positron annihilation spectroscopy.     

适于测量波长1.3μm的超短光脉冲的强度自相关系统

本文介绍了一种适于测量半导体激光器产生的波长1.3μm的超短光脉冲的强度自相关系统的原理和装置。对波长1.3μm的InGaAsP/InP激光器产生的超短光脉冲的测量结果表明,该装置具有很高的分辨率和较高的灵敏度。