Gap－LPE掺S浓度的控制及对发光效率的影响

报道了具有双ｎ型结构的ＧａＰ绿色发光二极管在汽相掺杂、液相外延过程中，对硫（Ｓ）掺杂浓度的控制和监测方法，并研究了掺Ｓ浓度对发光效率的影响。     

P－GaP中离子注入缺陷的形成

研究了Ｚｎ~＋离子注入ｐ－ＧａＰ半导体所引起的缺陷。在电流密度为０．０３μＡ／ｃｍ~２下，将注入Ｚｎ~＋离子剂量为１×１０１~（１４）离子／厘米~２的ＧａＰ样品腐蚀出蚀坑后用ＳＥＭ观察，结果表明，在离子注入区域有缺陷形成。     

第一性原理研究GaP的电子结构和光学性质

利用基于密度泛函理论（DFT）,采用赝势平面波方法和广义梯度近似法(GGA)研究了闪锌矿ZB结构和盐岩RS结构GaP的基态电子结构、光学性质,根据能带理论初步研究GaP基态能带结构、总态密度（DOS）和分波态密度（PDOS）,并计算出吸收系数,反射率,复介电函数,复折射率及能量损失函数。     

Dislocations in vapor phase epitaxial GaP

Dislocations in VPE GaP grown on (100) oriented LEC GaP substrates have been characterized, and their origins and effects on LED performance have been investigated. In non-nitrogen doped epilayers, the dislocations are found to originate in the substrate and propagate through the epilayers in straight lines in [100] and <211> directions. The dislocation density of the epilayer is found to be nearly equal to that of the substrate. Introduction of nitrogen during growth of the epilayer has been observed to bend these so-called “inclined≓ dislocations propagating through the layer into [0−1 1] directions in the (100) plane and thus produces segments of [0 −1 1] dislocations to relieve the lattice parameter mismatch due to N. The mismatch dislocation density is observed to be proportional to the N doping level. At very high N doping levels, > 10¹⁹ cm^-3, a large number of new inclined dislocations are observed, which may be in part due to GaN precipitation. The effects of dislocations on LED properties were investigated by measuring dislocation densities in the individual diodes using the electron beam induced current mode of the SEM and comparing this with the spot brightness and luminous flux. The dislocations were observed to produce dark spots in the EL emission in many cases. For a series of runs where all growth and processing parameters were fixed, a good correlation between B/J and dislocation density was observed with B/J decreasing with increasing dislocation density in the range < 1 × 10⁴ cm⁻² to 1 × 10⁶ cm⁻².     

纳米GaP粉体在水溶液中的分散性能及其PVP复合薄膜的制备

采用三种不同类型的分散剂对纳米磷化镓(GaP)粉体进行分散,并用测量滤液吸光度的方法来比较分散效果;测定了纳米GaP粉体的等电点,以及采用十二烷基苯磺酸钠分散时的Zeta电位,并初步制备了纳米GaP /聚乙烯吡咯烷酮(PVP)复合薄膜.结果表明,分散剂的选择、分散剂的浓度、pH值都对分散效果有着重要的影响;制备的纳米GaP / PVP复合薄膜具有良好的可见光透光性和一定的紫外线吸收性能.     

CVT法生长GaP多晶

阐述了CVT(化学气相输运)法生长GaP的基本反应和输运速度,采用CVT法生长出了GaP多晶.设计了石英管的结构以制造出一个局部的低温区域,防止了GaP在管壁的生长.生长出的GaP多晶相对密度为98;,红外透过率达到30;,努普硬度为611kg/mm2.散射颗粒测试表明主要的光散射颗粒为多晶中存在的孔隙.     

发光二极管阵列中上隔离沟槽的设计与制备

分析了发光二极管阵列上隔离沟槽的理想尺寸。采用湿法腐蚀方法对金属层、p-GaP层及多层AlGaInP进行了逐层腐蚀，完成了宽2μm深6μm的上隔离沟槽的制作。腐蚀后的上隔离沟槽边缘平整，其深度和宽度可以解决注入电流在相邻像素之间产生的干扰问题。     

GaP Raman Terahertz high accuracy spectrometer and its application to detect organic and inorganic crystalline defects

One of the most important uses of THz spectrometry is to detect defects in molecular structure or in crystals efficiently. We applied GaP Raman THz (GRT) spectrometer to detect and evaluate defects in inorganic and organic materials. High THz-wave absorption due to high defect density of GaSe crystal lowered the efficiency of THz wave generation, when the crystal is used as nonlinear material for DFG (Difference Frequency Generation). Defects in organic molecules could be observed as changes in frequency, intensities of the absorption, and broadenings of the spectra.     

GaN and other materials for semiconductor spintronics

Existing semiconductor electronic and photonic devices use the charge on electrons and holes to perform their specific functionality, such as signal processing or light emission. The field of semiconductor spintronics seeks to exploit the spin of charge carriers in new generations of transistors, lasers, and integrated magnetic sensors. The use of such devices depends on the availability of materials with practical magnetic-ordering temperatures. Here, we summarize recent progress in the development of GaN and other wide bandgap semiconductors that retain ferromagnetic properties above room temperature.     

Atomic layer epitaxy of AlP and (AlP)n(GaP)n superlattice using ethyldimethylamine alane as a new aluminum source

Atomic layer epitaxy (ALE) of AlP was realized using ethyldimethylamine alane (EDMAAl) as a new Al source. Self-limiting growth of AlP took place at one and two monolayers per ALE cycle. Secondary ion mass spectroscopy revealed that the amounts of incorporated impurities (carbon, hydrogen and oxygen) in ALE-grown AlP layers was greatly suppressed by using the new Al source, to nearly the same levels as in high-quality MOVPE-grown layers. We also achieved the successful ALE growth of (AlP)_n(GaP)_n short-period superlattices (SLs), taking advantage of the overlapping temperature windows of ALE-GaP and ALE-AlP. X-ray diffraction measurements showed reasonably good interface abruptness of SLs as low as 3. The PL emission peak from SLs involving Al-containing layers was observed in ALE growth for the first time.