Tedeschi, DavideFonseka, AruniBlundo, Elenadel Aguila, Andres GranadosGuo, YananTan, Hark HoeChristianen, P.C.M.Jagadish, ChennupatiPolimeni, AntonioDe Luca, Marta2022-07-221936-0851http://hdl.handle.net/1885/269869The formation of wurtzite (WZ) phase in III-V nanowires (NWs) such as GaAs and InP is a complication hindering the growth of pure-phase NWs, but it can also be exploited to form NW homostructures consisting of alternate zincblende (ZB) and WZ segments. This leads to different forms of nanostructures, such as crystal-phase superlattices and quantum dots. Here, we investigate the electronic properties of the simplest, yet challenging, of such homostructures: InP NWs with a single homojunction between pure ZB and WZ segments. Polarization-resolved microphotoluminescence (μ-PL) measurements on single NWs provide a tool to gain insights into the interplay between NW geometry and crystal phase. We also exploit this homostructure to simultaneously measure effective masses of charge carriers and excitons in ZB and WZ InP NWs, reliably. Magneto-μ-PL measurements carried out on individual NWs up to 29 T at 77 K allow us to determine the free exciton reduced masses of the ZB and WZ crystal phases, showing the heavier character of the WZ phase, and to deduce the effective mass of electrons in ZB InP NWs (me= 0.080 m0). Finally, we obtain the reduced mass of light-hole excitons in WZ InP by probing the second optically permitted transition Γ7C ↔ Γ7uV with magneto-μ-PL measurements carried out at room temperature. This information is used to extract the experimental light-hole effective mass in WZ InP, which is found to be mlh = 0.26 m0, a value much smaller than the one of the heavy hole mass. Besides being a valuable test for band structure calculations, the knowledge of carrier masses in WZ and ZB InP is important in view of the optimization of the efficiency of solar cells, which is one of the main applications of InP NWs.M.D.L. acknowledges support from the Swiss National Science Foundation under the Ambizione grant (grant no. PZ00P2_179801). We acknowledge the support of HFMLRU/FOM, member of the European Magnetic Field Laboratory (EMFL). Part of this work has been supported by EuroMagNET II under the EU contract number 228043. A.G.D.A. gratefully acknowledges the financial support of the Presidential Postdoctoral Fellowship program of the Nanyang Technological University. The Australian authors acknowledge the Australian Research Council, the Australian National Fabrication Facility (ANFF), ACT node, and the Australian Microscopy and Microanalysis Research Facility (AMMRF), ACT node. E.B. and A.P. acknowledge funding from the Regione Lazio programme “Progetti di Gruppi di ricerca” legge Regionale no. 13/2008 (SINFONIA project, prot. no. 85- 2017-15200) via LazioInnova spa. H.A.F. acknowledges funding from the EPSRC (grant no: EP/P000916/1).application/pdfen-AU© 2020 American Chemical Societywurtzite and zincblendeInP nanowirescrystal-phase homostructuresexcitonsmagneto-photoluminescencecarrier effective masslight hole202010.1021/acsnano.0c041742021-08-01