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Metal Organic Chemical Vapor Deposition (metal + organic_chemical_vapor_deposition)
Selected AbstractsGrowth of Fe doped semi-insulating GaN on sapphire and 4H-SiC by MOCVDPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2006M. Rudzi Abstract We report a study of iron doped GaN layers grown on sapphire and SiC by Metal Organic Chemical Vapor Deposition (MOCVD) using ferrocene as the Fe precursor. The influence of iron doping on the electrical, structural and morphological properties of the GaN layers was studied. A resistivity of 6x103 ,cm and higher was achieved in contrast to 3 ,cm for the undoped film. Defect selective etching showed that Fe doping increases the threading dislocation (TD) density which might be responsible for the increase in resistivity. A turn-on, turn-off effect is described and a memory effect which is responsible for a decrease of the surface quality of the samples. In situ annealing of the susceptor and the use of a clean liner after each growth run helps to reduce this effect and maintain the good quality of GaN layers. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] InGaN-based 518 and 488,nm laser diodes on c -plane GaN substratePHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2010Takashi Miyoshi Abstract We succeeded in fabricating InGaN-based laser diodes (LDs) with a wavelength of 518 and 488,nm under continuous wave (cw) operation. The both LDs structures were grown on conventional c -plane GaN substrates by metal organic chemical vapor deposition (MOCVD). The threshold current and threshold voltage were 45,mA and 5.5,V at 518,nm, 30,mA and 4.5,V at 488,nm, respectively. The lifetime test of these LDs was carried out under high driving temperature up to 80,°C in cw operation. Lifetime was estimated to be over 5000,h with an optical output power of 5,mW at 80,°C in 515,518,nm LDs from 1000,h operation, and was estimated to be over 10,000,h with an output power of 60,mW at 60,°C in 488,nm LDs from 2000,h operation. [source] Polarized Raman scattering studies of nonpolar a -plane GaN films grown on r -plane sapphire substrates by MOCVDPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 15 2006Haiyong Gao Abstract Nonpolar (110) a -plane GaN thin films were grown on r -plane (102) sapphire substrates by low-pressure metal organic chemical vapor deposition (MOCVD). The stress characteristics of the a -plane GaN films were investigated by means of polarized Raman scattering spectra in backscattering configurations. The experimental results show that there are strong anisotropic in-plane stresses within the epitaxial a -plane GaN films by calculating the corresponding stress tensors. The temperature dependence of Raman scattering spectra was studied in the range from 100 K to 550 K. The measurements reveal that the Raman phonon frequencies decrease with increasing temperature. The temperature at which nonpolar a -plane GaN films are strain free is discussed. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Growth and characterization study of multidimensional hierarchical ZnO nanostructuresPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 5 2007Dong Jun Park Abstract ZnO multidimensional hierarchical structure was successfully fabricated with the sequence of ZnO top layers/ZnO nanorods/ZnO buffer/Si(111) substrate by continuous controlling growth condition in metal organic chemical vapor deposition (MOCVD) system. Transmission electron microscopy (TEM) showed that ZnO nanorods in hierarchical structure had a single crystal hexagonal wurtzite structure with ,0001,ZnO growth direction. Only near band edge (NBE) emissions with very weak deep level emission are observed around 3.28 eV. This indicates that ZnO hierarchical structure grown by MOCVD shows a good optical quality and less interior defects. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effect of growth temperature of AlN interlayers on the properties of GaN epilayers grown on c-plane sapphire by metal organic chemical vapor depositionPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 10 2010J. S. Xue Abstract The effect of growth temperature of AlN interlayers on the properties of GaN epilayers grown on c-plane sapphire by metal organic chemical vapor deposition has been investigated by high resolution X-ray diffraction (HRXRD) and Raman spectroscopy. It is concluded that the crystalline quality of GaN epilayers is improved significantly by using the high temperature AlN (HT-AlN) interlayer in GaN buffers. The density of threading dislocation is reduced especially for edge type dislocations. Higher compressive stress exists in GaN epilayers with HT-AlN interlayer than with low temperature AlN (LT-AlN) interlayer, which is related to the reduction of strain relaxation caused by the formation of misfit dislocation. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The effect of absorption layer of different quantum well arrangement on optoelectronic characteristics of nitride-based photovoltaic cells grown by MOCVDPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue S2 2009Y. K. Fu Abstract In this study, III-nitride solar cells with multi-quantum well (MQW) absorption layer were grown on sapphire substrates by metal organic chemical vapor deposition (MOCVD). The effect of different quantum well (QW) arrangement on optoelectronic characteristics of III-nitrides photovoltaic cells was investigated. It was found that the upper quantum well (QW) layer will dominate electroluminescence (EL) emission mechanism and the electrical characteristics of solar cell. The advantage of modulating the short-circuit current density (JSC) and open-circuit voltage (VOC) can be obtained by different arrangement of blue and green QW in MQW absorption layer. The optimum electrical characteristics of solar cell with a JSC of 0.30 mA/cm2, a VOC up to 1.51 V, fill factor (FF) as high as 0.601, and a series resistance (RS) of 9 , can be obtained by using MQW absorption layer. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Formation of nitride laser cavities with cleaved facets on transferred laser diodes on GaAs substratesPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2008Wen-Chien Yu Abstract Smoothly cleaved facets with high reflectivities have been demonstrated on GaN laser diodes after the devices were transferred onto GaAs substrates. The GaN based laser diode structure was first fabricated by metal organic chemical vapor deposition (MOCVD) on c-plane sapphire substrates. The samples were then mounted onto thin GaAs substrates using wafer-bonding technology. Laser lift-off (LLO) technique was applied to remove the original sapphire substrate and transfer the GaN laser structure onto GaAs substrates. Since the cubic substrates have well-defined laser cavity cleavage facet, the GaN structures bonded onto the substrates also formed smooth facets after cleavage. The cleaved facets of GaN laser diodes have been characterized using atomic force microscopy (AFM) with less than 2 nm roughness. The present study demonstrated the feasibility of transferring GaN laser structures onto other more appealing substrates for formation of laser cavities. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Observations on surface morphologies and dislocations of a-plane GaN grown by metal organic chemical vapor depositionPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2007T. S. Ko Abstract In this study, we grew non-polar a-plane GaN thin films on r-plane sapphire using a series of growth conditions by metal-organic chemical vapor deposition. The results showed that high temperature and low-pressure conditions benefited two-dimension growth could lead to a fully coalesced a-plane GaN layer with a very smooth surface. The best surface morphology with an excellent mean roughness of 10.5 Å was obtained. The different thickness AlN as a nucleation layer and the different ,/, ratio were also considered. The results revealed that the surface morphology would get worse when the thickness of nucleation layer and ,/, ratio were away from the values of optimal condition. The observation of transmission electronic microscopy shown the lowest density of threading dislocations was 1.85×1010/cm2. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Impurity free vacancy disordering of self-assembled InGaAs quantum dots by using PECVD-grown SiO2 and SiNx capping filmsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 4 2003J. H. Lee Abstract Impurity free vacancy disordering (IFVD) of InGaAs self-assembled quantum dots (SAQDs) grown by metal organic chemical vapor deposition (MOCVD) method has been carried out at 700,°C for the time range from 1 min to 4 min by using SiO2 and SiNx,SiO2 dielectric capping layers. The photoluminescence (PL) peak was blue shifted up to 157 meV and its full width at half maximum (FWHM) was narrowed from 76 meV to 47 meV as the annealing time increased. The integrated PL intensity was increased after the thermal annealing, which may be attributed to a defect quenching. There was an optimum annealing condition to get the largest integrated PL intensity for each dielectric capping. SiNx,SiO2 double capping layers have been found to induce larger integrated PL intensity and better carrier confinement after the thermal annealing of SAQDs compared to SiO2 single capping layer, even though SiNx,SiO2 double capping induced larger blue-shift than SiO2 single capping. [source] MOCVD as a dry deposition method of ZnSe buffers for Cu(In,Ga)(S,Se)2 solar cellsPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 5 2004Susanne Siebentritt Abstract ZnSe prepared by metal organic chemical vapor deposition is used as a buffer layer in Cu(In,Ga)(S,Se)2 solar cells without any utilization of wet chemistry. Cell efficiencies are as good as cells with the conventional CdS buffer. Stability of unencapsulated cells under damp heat conditions is somewhat lower for the alternative buffer. The first stages of photoassisted growth are studied. X-ray photoemission spectroscopy shows that a continuous layer is formed. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||