Fletching-shaped Bi 4 Te 3 –ZnTe heterostructure nanowires

We investigated Bi 4 Te 3 –ZnTe axial heterostructure nanowires grown by physical vapor transport at the substrate temperature of 450 °C, utilizing ZnTe as the source and Bi 2 Te 3 as the catalyst. The temperatures of the source and catalyst materials were individually controlled by separating the source and catalyst boats. The axial heterostructure nanowires consisted of ZnTe and Bi 4 Te 3 segments. The Bi 4 Te 3 segment had an interesting fletching shape with three wings surrounded by a ZnO shell. A systematic redshift in the nanowire’s photoluminescence was observed as the excitation laser spot was moved from the heterojunction toward the root of the ZnTe segment, attributed to the formation of deep defect states under the Te-rich environment that resulted from using Bi 2 Te 3 as the catalyst instead of Bi.

Man Suk Song and Yong Kim

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