Characterization of InGaN quantum wells with gross fluctuations in width

Gross well-width fluctuations are observed in InGaN quantum wells (QWs), and have been linked to an overall three-dimensional morphology consisting of a network of interlinking InGaN strips. While these networks may be clearly observed in atomic force microscopy of appropriate uncapped epilayers, the surface morphology of capped (QW) samples reveals little or nothing of the subsurface structure of the InGaN. Hence transmission electron microscopy (TEM) must be used to determine the variations in QW thickness and composition. The network structure may be observed in either bright-field TEM or scanning transmission electron microscope high angle annular dark field images in plan-view studies of single QWs. It is suggested that multi-QWs could be imaged in cross section and the anisotropy of the network structure used as a potential signature of the three-dimensional morphology. The anisotropic nature of the network structure correlates well with the alignment of step edges in the GaN pseudosubstrates, and i...

[1]  C. Humphreys,et al.  Role of gross well-width fluctuations in bright, green-emitting single InGaN∕GaN quantum well structures , 2007 .

[2]  Debbie J. Stokes,et al.  Three-dimensional atom probe studies of an InxGa1−xN∕GaN multiple quantum well structure: Assessment of possible indium clustering , 2007 .

[3]  A. Uedono,et al.  Origin of defect-insensitive emission probability in In-containing (Al,In,Ga)N alloy semiconductors , 2006, Nature materials.

[4]  Colin J. Humphreys,et al.  Highlighting threading dislocations in MOVPE-grown GaN using an in situ treatment with SiH4 and NH3 , 2006 .

[5]  P. Hinze,et al.  Suppression of nonradiative recombination by V-shaped pits in GaInN/GaN quantum wells produces a large increase in the light emission efficiency. , 2005, Physical review letters.

[6]  E. Yu,et al.  Observation of In concentration variations in InGaN/GaN quantum-well heterostructures by scanning capacitance microscopy , 2005 .

[7]  C. Humphreys,et al.  Optical and microstructural studies of InGaN∕GaN single-quantum-well structures , 2005 .

[8]  C. Humphreys,et al.  Revealing all types of threading dislocations in GaN with improved contrast in a single plan view image , 2004 .

[9]  C. Humphreys,et al.  Growth and characterisation of GaN with reduced dislocation density , 2004 .

[10]  Colin J. Humphreys,et al.  Electron-beam-induced strain within InGaN quantum wells: False indium “cluster” detection in the transmission electron microscope , 2003 .

[11]  J. D. Smith,et al.  Growth of InGaN quantum dots on GaN by MOVPE, employing a growth temperature nitrogen anneal , 2003 .

[12]  A. G. Cullis,et al.  Electron-beam-induced segregation in InGaN/GaN multiple-quantum wells , 2003 .

[13]  S. Ting,et al.  Morphological evolution of InGaN/GaN quantum-well heterostructures grown by metalorganic chemical vapor deposition , 2003 .

[14]  Christian Teichert,et al.  Self-organization of nanostructures in semiconductor heteroepitaxy , 2002 .

[15]  J. Narayan,et al.  Effect of thickness variation in high-efficiency InGaN/GaN light-emitting diodes , 2002 .

[16]  C. Humphreys,et al.  Effect of growth interruptions on the light emission and indium clustering of InGaN/GaN multiple quantum wells , 2001 .

[17]  Paul R. C. Kent,et al.  Carrier localization and the origin of luminescence in cubic InGaN alloys , 2001 .

[18]  Kazumi Wada,et al.  Exciton localization in InGaN quantum well devices , 1998 .

[19]  Nakamura,et al.  The roles of structural imperfections in InGaN-based blue light-emitting diodes and laser diodes , 1998, Science.

[20]  Shuji Nakamura,et al.  Role of self-formed InGaN quantum dots for exciton localization in the purple laser diode emitting at 420 nm , 1997 .

[21]  E. C. Carr,et al.  CORRELATION OF CATHODOLUMINESCENCE INHOMOGENEITY WITH MICROSTRUCTURAL DEFECTS IN EPITAXIAL GAN GROWN BY METALORGANIC CHEMICAL-VAPOR DEPOSITION , 1997 .

[22]  Sugawara.  Theory of spontaneous-emission lifetime of Wannier excitons in mesoscopic semiconductor quantum disks. , 1995, Physical review. B, Condensed matter.

[23]  G. Andrew D. Briggs,et al.  Growth modes in heteroepitaxy of InGaN on GaN , 2005 .