Ultraviolet emission efficiency enhancement of a-plane AlGaN/GaN multiple-quantum-wells with increasing quantum well thickness Appl. Phys. Lett. 100, 261901 (2012) Photoexcited carrier dynamics in AlInN/GaN heterostructures Appl. Phys. Lett. 100, 242104 (2012) Photoluminescence recovery by in-situ exposure of plasma-damaged n-GaN to atomic hydrogen at room temperature AIP Advances 2, 022149 (2012) On conversion of luminescence into absorption and the van Roosbroeck-Shockley relation Appl. Phys. Lett. 100, 222103 (2012) Nature of optical transitions involving cation vacancies and complexes in AlN and AlGaN Appl. Phys. Lett. 100, 221107 (2012) Additional information on J. Appl. Phys. Dependence on the excitation power and temperature of the photoluminescence emission of GaAs quantum well laser structures using GaAs/AlAs superlattices in the waveguide is reported. The effects related to a quality reduction due to the presence of a thick ternary AlGaAs cladding layer in the bottom of the laser structure were elucidated by comparing to the photoluminescence of a similar waveguide structure, except for the AlGaAs bottom layer. The excitation power dependence shows the strong excitonic origin of the light emission in the temperature range 4-300 K in both structures. Carrier transport mechanisms through the superlattices is analyzed from the evolution of the photoluminescence of the quantum well and the superlattice confining layers; a structure dependent transparency temperature is defined, at which transport changes from tunneling assisted to extended minibands regime. The value of this parameter depends on the localized states in the superlattice minibands, caused by interface roughness.

Titania (TiO2) nanoparticles (NPs) are widely employed in applications that take advantage of their photochemical properties (e.g. pollutant degradation, photocatalysis). Here, we study the interrelation between crystallinity, surface hydroxylation and...

Structural and optical properties of InAs/AlAsSb quantum dots with GaAs(Sb) cladding layers Appl. Phys. Lett. 100, 243108 (2012) The electronic band structure of GaBiAs/GaAs layers: Influence of strain and band anti-crossing J. Appl. Phys. 111, 113108 (2012) Growth of AlN/SiC/AlN quantum wells on Si(111) by molecular beam epitaxy Appl. Phys. Lett. 100, 232112 (2012) Time-resolved photoluminescence, positron annihilation, and Al0.23Ga0.77N/GaN heterostructure growth studies on low defect density polar and nonpolar freestanding GaN substrates grown by hydride vapor phase epitaxy The optical properties of a novel system, the GaAs/GaP strained-layer superlattice, are studied and compared with a theoretical model. Photoluminescence and photoreflectance measurements revealed that among the set of superlattices under study type-I and type-II behaviors (similar to those found in the lattice-matched GaAsl AlAs system) are present. The evolution of the photoluminescence peaks as a function of temperature and excitation density supported the assignment of the transitions involved. This is to our knowledge the first observation of direct (type-I) and indirect (type-II) transitions in strained-layer superlattices. A comparison with a theoretical model has led to an estimation of the conduction-band offset as 0.4 eV, which is the first value obtained from experiment in a GaAs/GaP heterojunction.

The need of higher yields on the wafermanufacturing environment is pushing the yield analysts to develop new techniques and tools for yield improvement. With this scope, we present SmartBitTM, a software tool that provides detailed information about yield limitors by correlating bitmap to in-line defect data in an automatic mode, expediting the yield leaming task.Based on the spatial correlation of bitmap data and the information of defects coming from the inline inspections, SmartBitTM provides a pareto where yield loss sources are separated and weighted by impact. SmartBitTM also offers detailed information about the killer defects (defect class, origin, size, kill ratio and more) into a set of reports specially designed to obtain an overall view about the main problems affecting the fab yield. This is the key to fast and efficient yield leaming. These reports are generated automatically using data from the full production of memory-products enhancing the reliability and completeness of the analysis.