TY - JOUR
T1 - Value and Anisotropy of the Electron and Hole Mass in Pure Wurtzite InP Nanowires
AU - Tedeschi, D.
AU - De Luca, M.
AU - Granados Del Águila, A.
AU - Gao, Q.
AU - Ambrosio, G.
AU - Capizzi, M.
AU - Tan, H. H.
AU - Christianen, P. C.M.
AU - Jagadish, C.
AU - Polimeni, A.
N1 - Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/10/12
Y1 - 2016/10/12
N2 - The effective mass of electrons and holes in semiconductors is pivotal in determining the dynamics of carriers and their confinement energy in nanostructured materials. Surprisingly, this quantity is still unknown in wurtzite (WZ) nanowires (NWs) made of III-V compounds (e.g., GaAs, InAs, GaP, InP), where the WZ phase has no bulk counterpart. Here, we investigate the magneto-optical properties of InP WZ NWs grown by selective-area epitaxy that provides perfectly ordered NWs featuring high-crystalline quality. The combined analysis of the energy of free exciton states and impurity levels under magnetic field (B up to 29 T) allows us to disentangle the dynamics of oppositely charged carriers from the Coulomb interaction and thus to determine the values of the electron and hole effective mass. By application of B - along different crystallographic directions, we also assess the dependence of the transport properties with respect to the NW growth axis (namely, the WZ ĉ axis). The effective mass of electrons along ĉ is me∥ = (0.078 ± 0.002) m0 (m0 is the electron mass in vacuum) and perpendicular to ĉ is me = (0.093 ± 0.001) m0, resulting in a 20% mass anisotropy. Holes exhibit a much larger (∼320%) and opposite mass anisotropy with their effective mass along and perpendicular to ĉ equal to mh = (0.81 ± 0.18) m0 and mh = (0.250 ± 0.016) m0, respectively. While no full consensus is found with current theoretical results on WZ InP, our findings show trends remarkably similar to the experimental data available in WZ bulk materials, such as InN, GaN, and ZnO.
AB - The effective mass of electrons and holes in semiconductors is pivotal in determining the dynamics of carriers and their confinement energy in nanostructured materials. Surprisingly, this quantity is still unknown in wurtzite (WZ) nanowires (NWs) made of III-V compounds (e.g., GaAs, InAs, GaP, InP), where the WZ phase has no bulk counterpart. Here, we investigate the magneto-optical properties of InP WZ NWs grown by selective-area epitaxy that provides perfectly ordered NWs featuring high-crystalline quality. The combined analysis of the energy of free exciton states and impurity levels under magnetic field (B up to 29 T) allows us to disentangle the dynamics of oppositely charged carriers from the Coulomb interaction and thus to determine the values of the electron and hole effective mass. By application of B - along different crystallographic directions, we also assess the dependence of the transport properties with respect to the NW growth axis (namely, the WZ ĉ axis). The effective mass of electrons along ĉ is me∥ = (0.078 ± 0.002) m0 (m0 is the electron mass in vacuum) and perpendicular to ĉ is me = (0.093 ± 0.001) m0, resulting in a 20% mass anisotropy. Holes exhibit a much larger (∼320%) and opposite mass anisotropy with their effective mass along and perpendicular to ĉ equal to mh = (0.81 ± 0.18) m0 and mh = (0.250 ± 0.016) m0, respectively. While no full consensus is found with current theoretical results on WZ InP, our findings show trends remarkably similar to the experimental data available in WZ bulk materials, such as InN, GaN, and ZnO.
KW - Wurtzite InP nanowires
KW - carrier effective mass
KW - excitons
KW - impurity states
KW - magneto-photoluminescence
UR - http://www.scopus.com/inward/record.url?scp=84991329797&partnerID=8YFLogxK
U2 - 10.1021/acs.nanolett.6b02469
DO - 10.1021/acs.nanolett.6b02469
M3 - Article
SN - 1530-6984
VL - 16
SP - 6213
EP - 6221
JO - Nano Letters
JF - Nano Letters
IS - 10
ER -