title: Tailoring the optical characteristics of microsized InP nanoneedles directly grown on silicon.
abstract: Nanoscale self-assembly offers a pathway to realize heterogeneous integration of III-V materials on silicon. However, for III-V nanowires directly grown on silicon, dislocation-free single-crystal quality could only be attained below certain critical dimensions. We recently reported a new approach that overcomes this size constraint, demonstrating the growth of single-crystal InGaAs/GaAs and InP nanoneedles with the base diameters exceeding 1 μm. Here, we report distinct optical characteristics of InP nanoneedles which are varied from mostly zincblende, zincblende/wurtzite-mixed, to pure wurtzite crystalline phase. We achieved, for the first time, pure single-crystal wurtzite-phase InP nanoneedles grown on silicon with bandgaps of 80 meV larger than that of zincblende-phase InP. Being able to attain excellent material quality while scaling up in size promises outstanding device performance of these nanoneedles. At room temperature, a high internal quantum efficiency of 25% and optically pumped lasing are demonstrated for single nanoneedle as-grown on silicon substrate. Recombination dynamics proves the excellent surface quality of the InP nanoneedles, which paves the way toward achieving multijunction photovoltaic cells, long-wavelength heterostructure lasers, and advanced photonic integrated circuits.
authors.affiliation: Department of Electrical Engineering and Computer Sciences, University of California at Berkeley , Berkeley, California 94720, United States.
authors.forename: Kun
authors.initials: K
authors.lastname: Li
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.forename: Fan
authors.initials: F
authors.lastname: Ren
authors.forename: Kar Wei
authors.initials: KW
authors.lastname: Ng
authors.forename: Thai-Truong D
authors.initials: TT
authors.lastname: Tran
authors.forename: Roger
authors.initials: R
authors.lastname: Chen
authors.forename: Connie J
authors.initials: CJ
authors.lastname: Chang-Hasnain