| Crystal Research and Technology |
The doping of germanium with zinc from a remote, temperature-stabilized source was studied under microgravity. A nominally undoped Ge-crystal was grown by the Gradient-Freeze technique with the melt surface being in permanent contact with a gaseous atmosphere of zinc. The dopant and carrier concentrations in the solidified Germanium were measured by SIMS, Hall and resistance measurements and compared with the results of a terrestrial reference experiment as well as with concentration profiles calculated on the basis of the thermodynamics of the growth system. The results prove the possibility of vapour phase doping under microgravity. Moreover, the Zn-concentration at the initial phase boundary even agrees well with the equilibrium value, strongly indicating a nearly homogeneous distribution of the dopant within the melt before the crystallization.
Keywords: Zn, Ge, microgravity
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