Wide InP nanowires with wurtzite/zincblende superlattice segments are type-II whereas narrower nanowires become type-I: an atomistic pseudopotential calculation.

Zhang, Lijun; Luo, Jun-Wei; Zunger, Alex; Akopian, Nika; Zwiller, Val; Harmand, Jean-Christophe · Nano Lett · 2010

basic_science · Level V

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Abstract

Nanowire-superlattices with different structural phases along the nanowire direction, such as wurtzite (WZ) and zincblende (ZB) forms of the same compound, often exhibit a "type II" band-alignment with electrons on ZB and holes on WZ. This is a material property of most of III-V semiconductors. We show via InP nanowires that as the nanowire diameter decreases, quantum-confinement alters this basic material property, placing both electrons and holes on the same (ZB) phase. This structural design causes a dramatic increase in absorption strength and reduced radiative lifetime.