Controlling the abruptness of axial heterojunctions in III-V nanowires: beyond the reservoir effect.
Heterostructure nanowires have many potential applications due to the avoidance of interface defects by lateral strain relaxation. However, most heterostructure semiconductor nanowires suffer from persistent interface compositional grading, normally attributed to the dissolution of growth species in the common alloy seed particles. Although progress has been made for some material systems, most binary material combinations remain problematic due to the interaction of growth species in the alloy. In this work we investigate the formation of interfaces in InAs-GaAs heterostructures experimentally and theoretically and demonstrate a technique to attain substantially sharper interfaces. We show that by pulsing the Ga source during heterojunction formation, In is pushed out before GaAs growth initiates, greatly reducing In carry-over. This procedure will be directly applicable to any nanowire system with finite nonideal solubility of growth species in the alloy seed particle and greatly improve the applicability of these structures in future devices.
Solid State Physics, Lund University, Box 118, SE-221 00 Lund, Sweden. Kimberly.Dick@ftf.lth.se
Kimberly A
KA
Dick
Jessica
J
Bolinsson
B Mattias
BM
Borg
Jonas
J
Johansson
D001152:Arsenicals / Q000737:chemistry*; D004566:Electrodes; D005708:Gallium / Q000737:chemistry*; D007204:Indium / Q000737:chemistry*; D008422:Materials Testing; D012666:Semiconductors; D013499:Surface Properties
D001152:Arsenicals; D007204:Indium; C043055:gallium arsenide; D005708:Gallium; C076773:indium arsenide