选择区域生长高质量InGaAsP多量子阱材料

采用LP-MOVPE在SiO_2掩膜的InP衬底上实现了高质量的InGaAsP多量子阱(MQW)的选择区域生长(SAG)。通过改变生长温度和生长压力，MQW的适用范围由C波段扩展至L波段，即MQW的光致发光波长从1546nm延展至1621nm。光致发光(PL)测试表明

InGaN/AlGaN双异质结绿光发光二极管

报道了用LP-MOVPE技术在蓝宝石(α-Al_2O_3)衬底上生长出以双掺Zn和Si的InGaN为有源区的绿光InGaN/AlGaN双异质结结构，并研制成功发射波长为520-540nm的绿光LED。

低压-金属有机物汽相外延生长的Ga（1-x）InxAs/InP激光器中深能级的研究

应用深能级瞬态谱(DLTS)技术详细研究低压-金属有机物汽相外延(LP-MOVPE)生长的Ga_(0.74)In_(0.53)As/InP量子阱、宽接触和质子轰击条形异质结激光器中的深能级。样品的DLTS表明,在宽接触激光器的i-Ga_(0.47)In(0.53)As有源层里观察到 H1(Ev+0.09eV)和E1(E_c-0.35eV)陷阱,它们可能分别与样品生长过程中扩散到i-Ga_(0.47)In_(0.53)As有源层的Zn和材料本身的原生缺陷有关。而条形激光器的i-Ga_(0.47)In_(0.53)A_s有源层的 H_2(E_v+0.11eV)和 E_2(E_q-0.42eV)陷阱则可能是H1和E1与质子轰击引起的损伤相互作用的产物 。

Growth and characterization of GaN on LiGaO2 and LiAlO2

The nearly lattice-matched LiGaO2 and LiAlO2 substrates have been used for the growth of GaN by LP-MOVPE. GaN epilayers have been grown on the two substrates at very low input partial pressure of hydrogen and relatively low growth temperature. The difference in the growth rate, crystal and optical qualities of hexagonal GaN epilayers grown on LiAlO2 and LiGaO2 substrate with two polar domains are investigated. LiAlO2 and LiGaO2 single crystal with a single domain structure and an adequate surface plane are promising substrates for the growth of high quality of hexagonal GaN thin films.

Growth and characterization of GaN on LiGaO2

The nearly lattice-matched (0 0 1)LiGaO2 substrates have been used for the growth of GaN by LP-MOVPE, GaN epilayers have been grown on both domains at very low input partial pressure of hydrogen and relatively low growth temperature. The differences in the growth rate, crystal and optical qualities of hexagonal GaN epilayers grown on LiGaO2 substrate with two polar domains are investigated. LiGaO2 single crystal with a single domain structure and an adequate surface plane is a promising substrate for the growth of high quality of hexagonal GaN thin films. (C) 1998 Published by Elsevier Science B.V. All rights reserved.

Characteristics of oxide-free InGaAlAs layers grown by narrow stripe selective MOVPE

Narrow stripe selective MOVPE has been used to grow high quality oxide-free InGaAlAs layers on an InP substrate patterned with SiO2 masks at optimized growth conditions. Mirror-like surface morphologies and abrupt cross sections are obtained in all samples without spike growth at the mask edge. For the narrow stripe selectively grown InGaAlAs layers with a mesa width of about 1.2 mu m, a bandgap wavelength shift of 70 nm, a photoluminescence (PL) intensity of more than 80% and a PL full width at half maximum (FWHM) of less than 60 meV are obtained simultaneously with a small mask width variation from 0 to 40 mu m. The characteristics of the thickness enhancement ratio and the PL spectrum dependence on the mask width are presented and explained by considering both the migration effect from a masked region and the lateral vapour diffusion effect.

The Soldier's Wife (LP)

Audio recording of 10 tracks funded by Legacy, The Australia Council, and Arts Queensland. The recordings explore the untold stories of soldiers' wives through song. It features the vocal and songwriting talents of Jackie Marshall, Bertie Page, Sahara Beck, Emma Bosworth, Roz Pappalardo, and Kristy Apps. Recorded, Mixed, Mastered, and Co-Produced by Phil Graham.

Technological adoption and use after mass market displacement: The case of the LP record

This paper investigates the reasons why some technologies, defying general expectations and the established models of technological change, may not disappear from the market after having been displaced from their once-dominant status. Our point of departure is that the established models of technological change are not suitable to explain this as they predominantly focus on technological dominance, giving attention to the technologies that display highest performance levels and gain greatest market share. And yet, technological landscapes are rife with technological designs that do not fulfil these conditions. Using the LP record as an empirical case, we propose that the central mechanism at play in the continuing market presence of once-dominant technologies is the recasting of their technological features from the functional-utilitarian to the aesthetic realm, with an additional element concerning communal interaction among users. The findings that emerge from our quantitative textual analysis of over 200,000 posts on a prominent online LP-related discussion forum (between 2002 and 2010) also suggest that the post-dominance technology adopters and users appear to share many key characteristics with the earliest adopters of new technologies, rather than with late-stage adopters which precede them.

Optimization of off-oriented Ge substrates for MOVPE-grown GaAs solar cells

GaAs/Ge heterostructures having abrupt interfaces were grown on 2degrees, 6degrees, and 9degrees off-cut Ge substrates and investigated by cross-sectional high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy, photoluminescence spectroscopy and electrochemical capacitance voltage (ECV) profiler. The GaAs films were grown on off-oriented Ge substrates with growth temperature in the range of 600-700degreesC, growth rate of 3-12 mum/hr and a V/III ratio of 29-88. The lattice indexing of HRTEM exhibits an excellent lattice line matching between GaAs and Ge substrate. The PL spectra from GaAs layer on 6degrees off-cut Ge substrate shows the higher excitonic peak compared with 2degrees and 9degrees off-cut Ge substrates. In addition, the luminescence intensity from the GaAs solar cell grown on 6degrees off-cut is higher than on 9degrees off-cut Ge substrates and signifies the potential use of 6degrees off-cut Ge substrate in the GaAs solar cells industry. The ECV profiling shows an abrupt film/substrate interface as well as between various layers of the solar cell structures.

Comparison of Optimum Reactive Power Schedule with Different Objectives Using LP Technique

Three algorithms for reactive power optimization are proposed in this paper with three different objective functions. The objectives in the proposed algorithm are to minimize the sum of the squares of the voltage deviations of the load buses, minimization of sum of squares of voltage stability L-indices of load buses (:3L2) algorithm, and also the objective of system real power loss (Ploss) minimization. The approach adopted is an iterative scheme with successive power flow analysis using decoupled technique and solution of the linear programming problem using upper bound optimization technique. Results obtained with all these objectives are compared. The analysis of these objective functions are presented to illustrate their advantages. It is observed comparing different objective functions it is possible to identify critical On Load Tap Changers (OLTCs) that should be made manual to avoid possible voltage instability due to their operation based on voltage improvement criteria under heavy load conditions. These algorithms have been tested under simulated conditions on few test systems. The results obtained on practical systems of 24-node equivalent EHV Indian power network, and for a 205 bus EHV system are presented for illustration purposes.

GaN-based LEDs grown on 6-inch diameter Si (111) substrates by MOVPE

The issues and challenges of growing GaN-based structures on large area Si substrates have been studied. These include Si slip resulting from large temperature non-uniformities and cracking due to differential thermal expansion. Using an A1N nucleation layer in conjunction with an AlGaN buffer layer for stress management, and together with the interactive use of real time in-situ optical monitoring it was possible to realise flat, crack-free and uniform GaN and LED structures on 6-inch Si (111) substrates. The EL performance of processed LED devices was also studied on-wafer, giving good EL characteristics including a forward bias voltage of ∼3.5 V at 20 mA from a 500 μm × 500 μm device. © 2009 SPIE.