A Numerical Study on the Growth Process of InGaSb Crystals Under Microgravity with Interfacial Kinetics

Abstract

In x Ga 1−x Sb bulk crystals are to be grown using a GaSb(seed)/InSb/GaSb(feed) sandwich-structured sample onboard the International Space Station (ISS). The InGaSb crystals will be grown on top of GaSb seed single crystals with different orientations viz., (111)A, (111)B, (110), (100) in order to examine and understand the growth kinetics of the crystals. In the present work, a numerical model of the crystal growth system has been developed to investigate the interface kinetics effects on the growth process by taking kinetics coefficient into account. The proposed numerical model was applied to evaluate the effect of crystal orientation on growth rate. Simulation results showed that the kinetics coefficient, whose value depends on crystal orientation, affected the growth rate of InGaSb crystal and the dissolution rate of GaSb feed crystal in the sandwich system. Nomenclaturevector in the vertical direction f interface position (m) g gravity acceleration (m · s −2 ) La latent heat (J · kg −1 ) m slope of the interface n unit vector normal to the interface p pressure (Pa) T temperature (K) u fluid velocity component in the horizontal direction (m · s −1 ) t time (s) v fluid velocity vector (m · s −1 ) v fluid velocity component in the vertical direction (m · s −1 ) x horizontal direction coordinate (m) y vertical direction coordinate (m) y + dimensionless wall distance (-) G acceleration normalised by gravity of Earth (m · s −2 )Greek symbols α thermal diffusivity (m 2 · s −1 ) β kinetics coefficient (m · s −1 ) β(0) kinetics coefficient at the unperturbed interface (m · s −1 ) β st kinetics coefficient of steps (m · s −1 ) β C solutal expansion coefficient (-) Microgravity Sci. Technol. β T thermal expansion coefficient (K −1 ) λ thermal conductivity (W · m −1 · K −1 ) μ viscosity (kg · m −1 · s −1 ) ρ density (kg · m −3 ) ν kinematic viscosity (m 2 · s −1 ) C concentration difference (-)

Investigation of directionally solidified InGaSb ternary alloys from Ga and Sb faces of GaSb(111) under prolonged microgravity at the International Space Station

“…19 A numerical model was developed to evaluate the effect of crystal orientation on the growth rate. 20 The International Space Station (ISS) provides prolonged microgravity conditions for materials production, space medicine, plant biology, biotechnology, and communications, which have been explored since 2000. Significant results in the fields of cell biology, plant architecture, human physiology, and materials science have been reported utilizing the space platform "ISS".…”

Numerical simulation of InGaSb crystals growth under microgravity onboard the international space station

“…This is mainly due to the suppression of convective flow in the solution (melt). Therefore, several experimental and numerical studies were performed for a better understanding of the InGaSb crystal dissolution and growth process by comparing the terrestrial and microgravity conditions [3][4][5][6][7][8][9]. Also recently Inatomi et al have compared the InGaSb crystals grown on the ISS and on Earth, and demonstrated that the shape of the growth interface was a slightly concave towards the seed under microgravity [10].…”

Numerical simulation of InGaSb crystals growth under microgravity onboard the international space station

“…This is mainly due to the suppression of convective flow in the solution (melt). Therefore, several experimental and numerical studies were performed for a better understanding of the InGaSb crystal dissolution and growth process by comparing the terrestrial and microgravity conditions [3][4][5][6][7][8][9]. Also recently Inatomi et al have compared the InGaSb crystals grown on the ISS and on Earth, and demonstrated that the shape of the growth interface was a slightly concave towards the seed under microgravity [10].…”