Photoluminescent and structural properties of GaN thin films obtained by radical-beam gettering epitaxy on porous GaAs (0 0 1)

The Mechanism of Growth of GaN Films by the HVPE Method on SiC Synthesized by the Substitution of Atoms on Porous Si Substrates

“…To form an ordered mesoporous structure a standard technology was used. [1][2][3] Fig. 1 shows a typical SEM micrograph of the cross-section of the Si (111) substrate with a mesoscopic pore system.…”

“…Thus two variants will be considered: i) two-dimensional nuclei of "emptiness" are being formed on the GaN layer surface ii) real GaN nuclei are formed. The free energy of the nuclei of two-dimensional etch pits in GaN or 2D-GaN nuclei can be written in general form as follows 14 F = 2πhγr − πr 2 h ξ − h Aκ ln r r 0 , [1] where A = G GaN b 2 /4π, r 0 is the radius of the dislocation core, beyond which the theory of the elastic continuum is valid (below for estimations we will assume that r 0 ∼ a); G GaN is the shear modulus of GaN; b is the Burgers vector of dislocation in GaN; κ = cos ψ 2 + sin ψ 2 /(1 − ν) for a dislocation of a mixed type, b cos ψ is the helical component of the Burgers vector, b sin ψ is the edge component of the Burgers vector, 17 ν is Poisson's ratio of GaN, for purely edge dislocation κ = 1/(1 − ν) , and for a purely screw dislocation κ = 1; is the volume per molecule in GaN, ∼ 10 −29 m −3 ; γ is the surface energy of the GaN face, ξ is the chemical affinity (the chemical affinity formula for GaN growth will be given below). The minus sign in formula (1) before the last term indicates the formation of an etching pit at the site where the dislocation was.…”

Improvement of Porous GaAs (100) Structure through Electrochemical Etching Based on DMF Solution

“…Porous GaAs has been identified as a potential substrate for promoting low threading dislocations and strain for overgrown epitaxial layer [1]. Producing porous GaAs in a well-defined structure with high pore distribution density is quite challenging.…”

Optical properties of p-type porous GaAs

“…Porous GaAs attracts attention in recent years as a promising substrate for GaN epitaxy, for the purpose of minimizing some negative effects due to large lattice mismatch and difference in the thermal expansion coefficient of GaAs and GaN, which usually leads to high strains and the high defect density in GaN/GaAs structures. Among the first attempts of using porous GaAs as a substrate for GaN epitaxy, it was reported in [4][5][6]. Earlier [7], we reports about properties of cubic GaN films obtained by nitridation of porous GaAs (001).…”