Experimental study of the solid–liquid interface dynamics and chemical segregation in concentrated semiconductor alloy Bridgman growth

Modeling of a space experiment on Bridgman solidification of concentrated semiconductor alloy

“…From the numerical modeling, a small increase of the convective intensity, because of the solutal effect, is found, which can be generally neglected. On the ground, experiments and numerical simulation [3,5] show a strong damping solutal effect on the convection, which leads to a significant increase of radial segregation and interface curvature during the solidification of concentrated Ga 1Àx In x Sb (x ¼ 0:1 and x ¼ 0:2) alloys. On the contrary, in space, because the configuration is rather horizontal Bridgman, the level of the convection is almost constant during the solidification, so the increase of the radial segregation and interface curvature are limited [5].…”

“…The no-slip and, no-flux conditions for velocity and solute field, respectively, are imposed on the solid boundaries of the liquid domain. In practice, dewetting occurred [1], however, leading to only 50 mm of free surface, which is neglected in this analysis. At the solid-liquid interface, the thermal flux balance and solute balance conditions are…”

“…The purpose of the experiment is to study the thermal, chemical and dewetting phenomena during Bridgman growth of concentrated alloys under microgravity conditions [1,2] as compared with similar ground experiments [2,3]. The advanced gradient heating facility (AGHF) Bridgman furnace has a heating element and a cooling zone separated by an adiabatic zone.…”

Bridgman growth of concentrated GaInSb alloys with improved compositional uniformity under alternating magnetic fields

“…The use of this material as substrate for the thermophotovoltaic cells necessitates low band gaps which correspond to highly In-doped alloys. But experimental works on the concentrated Ga 1Àx In x Sb (x ¼ 0:1 and 0:2) alloy solidification, show a poor quality of the crystals because of large chemical segregations, which induce morphological destabilization of the crystal-melt interface [1,2].…”

Contribution to the stability analysis of the dewetted Bridgman growth under microgravity conditions

“…However attempts to get advantage of this concept to grow dewetted ice on the earth have failed [16]. For all these configurations, the theory of dewetting occurrence is well established and in all cases it is possible to compute the crystal-crucible gap thickness, which is of the order of some ten micrometers, in good agreement with the experimental results in space [17] and on the ground [9,17]. An impressive experimental observation concerns the stability of the growth, especially under microgravity conditions; the gap thickness remains constant along several centimetres of grown crystal.…”