Strain-relaxed InGaAs buffer layers grown by molecular-beam epitaxy for 1.3 μm Fabry–Pérot optical modulators

AbstractThe Hall effect and photoluminescence measurements combined with annealing and/or ion milling were used to study the electrical and optical properties of HgCdTe films grown by molecular-beam epitaxy on GaAs substrates with ZnTe and CdTe buffer layers. Unintentional donor doping, likely from the substrate, which resulted in residual donor concentration of the order of 1015 cm−3, was observed in the films. Also, acceptor states, possibly related to structural defects, were observed.

Download Full-text

Selective Area Growth and Structural Characterization of GaN Nanostructures on Si(111) Substrates

Crystals ◽

10.3390/cryst8090366 ◽

2018 ◽

Vol 8 (9) ◽

pp. 366 ◽

Cited By ~ 8

Author(s):

Alexana Roshko ◽

Matt Brubaker ◽

Paul Blanchard ◽

Todd Harvey ◽

Kris Bertness

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Lattice Mismatch ◽

Buffer Layers ◽

Selective Area Growth ◽

Gan Nanowires ◽

Selective Area ◽

Area Growth ◽

Eutectic Formation

Selective area growth (SAG) of GaN nanowires and nanowalls on Si(111) substrates with AlN and GaN buffer layers grown by plasma-assisted molecular beam epitaxy was studied. For N-polar samples filling of SAG features increased with decreasing lattice mismatch between the SAG and buffer. Defects related to Al–Si eutectic formation were observed in all samples, irrespective of lattice mismatch and buffer layer polarity. Eutectic related defects in the Si surface caused voids in N-polar samples, but not in metal-polar samples. Likewise, inversion domains were present in N-polar, but not metal-polar samples. The morphology of Ga-polar GaN SAG on nitride buffered Si(111) was similar to that of homoepitaxial GaN SAG.

Download Full-text

Effect of V/III Ratio on the Properties of GaN Layers Grown by Molecular Beam Epitaxy Using NH3

MRS Proceedings ◽

10.1557/proc-512-69 ◽

1998 ◽

Vol 512 ◽

Author(s):

N. Grandjean ◽

M. Leroux ◽

J. Massies ◽

M. Mesrine ◽

P. Lorenzini

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Flux Ratio ◽

Buffer Layers ◽

Force Microscopy ◽

Sapphire Substrates ◽

Atomic Force ◽

Piezoelectric Field ◽

Secondary Ion

ABSTRACTAmmonia as nitrogen precursor has been used to grow III-V nitrides by molecular beam epitaxy (MBE) on c-plane sapphire substrates. The efficiency of NH3 has been evaluated allowing the determination of the actual V/III flux ratio used during the GaN growth. The effects of the V/III ratio variation on the GaN layer properties have been investigated by photoluminescence (PL), Hall measurements, atomic force microscopy (AFM), and secondary ion mass spectroscopy (SIMS). It is found that a high V/III ratio leads to the best material quality. Optimized GaN thick buffer layers have been used to grow GaN/AlGaN quantum well (QW) heterostructures. Their PL spectra exhibit well resolved emission peaks for QW thicknesses varying from 3 to 15 monolayers. From the variation of the QW energies as a function of well width, a piezoelectric field of 450 kV/cm is deduced.

Download Full-text