多孔氧化铝薄膜的制备和光学特性研究

采用阳极氧化法制备了二维有序纳米孔氧化铝膜.研究了工艺参数对多孔薄膜有序性、孔径、膜厚度等的影响，测量了多孔氧化铝有序膜的光透过、光吸收和光发射等光学特性.结果表明，在波长360 nm附近多孔氧化铝有序膜的光透过谱线和光吸收谱线发生突变，波长大于360 nm时，光透过增强；波长小于360 nm时，光吸收增强.多孔氧化铝有序膜的光致发光强度和峰位与激发光波长有关，光致发光谱范围在340~600 nm.     

静压下Znse/Zn1-xCdxSe应变超晶格的光致发光研究

本文首次在室温和0-2.5GPa静压范围内研究了Znse/Zn0.74Cd0.26Se应变超晶格的静压光致发光,观察到了室温条件下的超晶格阱层的重空穴激子跃迁随压力的亚线性变化的特性.经过计算机拟合实验数据得到了一阶和二阶压力系数.理论计算得到的一阶压力系数与实验得到的压力系数符合得较好.     

多孔硅发光时间效应及物理模型

通过剖析与阳极氧化时间、大气中存放时间、激光照射时间等与时间有关的多孔硅光致发光实验现象，提出了一个既通过局域在量子线上激子态复合同时又通过一热释过程后经表面态复合的综合发光机理，它能定性地解释多孔硅发光的时间效应及其它实验结果．     

8-羟基喹啉铝在多孔铝中的发光研究

利用多孔铝非常高的孔隙率,将8-羟基喹啉铝(Alq3)镶嵌到多孔铝中,得到Alq3/多孔铝镶嵌膜,研究了不同条件下制备的多孔铝镶嵌膜的荧光光谱。实验表明,Alq3在多孔铝中的发光峰位在490 nm左右,比其在固态粉末状态蓝移了许多。Alq3/多孔铝镶嵌膜的发光特性与多孔铝中嵌入Alq3分子的数量及聚集程度有关。当分子数量较多、聚集程度较大时,发光增强,光谱峰位红移,但聚集程度太大时,易发生荧光猝灭现象。数量较多时,由于Alq3分子大多以范德瓦尔斯力结合,聚体较少,所以峰位移动幅度不大。实验中还发现,Alq3因为处在小孔中,光学性质稳定,荧光光谱带宽超过100 nm,比一般染料大得多,这使Alq3/多孔铝镶嵌膜有可能在固体可调谐激光器方面得到新的应用;同时也为探究Alq3/多孔铝镶嵌膜在电致发光器件中的发光特性奠定了基础,为将其进一步推向实用提供了实验依据。     

Temperature－Dependent Photoluminescence of ZnTe Films Grown on Si Substrates

ZnTe films have been prepared on Si substrates by metal-organic chemical vapour deposition (MOCVD), and the temperature-dependent photoluminescence (PL) properties were investigated. The near-band-edge (NBE) emission of the ZnTe sample at 83K shows an asymmetry line shape, which can be decomposed into two Gaus-siam lines labelled by FE and BE. Temperature-dependent PL intensity of the NBE peak shows two variation regions, and an expression with two dissociation channels fits well to the experimental data. The results of the temperature-dependent full width at half maximum (FWHM) and peak energy were well understood under the framework of the two-dissociation-channel model. That is, at low temperature, the emission from bound excitons governs the NBE peak, while above 157K, the free exciton emission becomes dominant gradually. A simple model with three energy levels was employed to describe the variation in emission intensity of BE and FE with temperature.     

Structural Characteristics and Photoluminescence of Zinc Oxide Nanocrystals

We have prepared zinc oxide nanocrystals using a new type of solid-state reaction.The nanosized grains were obtained by changing the heat treatment temperature and the sizes were determined to be from 10 to 42 nm.The lattice vibrational Raman spectra were measured and assigned at different grain sizes.We observed a strong visible emission centred at 580 nm in the nanosized ZnO at room temperature.We have investigated the photoluminescence properties under different grain sizes after annealing.The weakening of the luminescence is attributed to the decrease of intrinsic structural defects,mainly,oxygen vacancies and the increase of the grain size in the nanocrystals.     

磁共振光学测量——自旋共振的延伸和发展

 过去的几十年中,电子自旋共振技术(ESR)在研究半导体材料缺陷及材料的电性能方面起到不可估量的作用。然而,当探测现代外延层、层问结构和超晶格时,由于材料体积小而导致总自旋数目减少与电子自旋共振的低灵敏度相矛盾,则ESR的重要性就显现不出。磁共振光学测量(ODticalDetectionofMagneticResonance,简称ODMR)的出现是一种物理和技术上的必然选择。本文对ODMR进行简要介绍,以便对磁共振技术感兴趣者了解这一新技术。     

多孔硅光致发光的温度效应研究

通过对多孔硅光致发光峰随测量温度变化的研究，发现随测量温度的下降，光致发光峰位有两种截然不同的移动方向：发光峰中心波长较长的样品，主峰向低能方向移动(即红移)；而发光峰位波长较短的样品则向高能方向移动(即蓝移).根据多孔硅光致发光峰的温度效应，定性地给出了发光效率随波长变化的模拟曲线，并由此能较好地解释多孔硅光致发光峰位随温度变化而移动的实验现象. 关键词：