Excitonic properties of wurtzite InP nanowires grown on silicon substrate

Abstract

In order to investigate the optical properties of wurtzite (Wz) InP nanowires grown on Si(001) by solid source molecular beam epitaxy with the vapour-liquid-solid method, the growth temperature and V/III pressure ratio have been optimized to remove any zinc-blende insertion. These pure Wz InP nanowires have been investigated by photoluminescence (PL), time-resolved PL and PL excitation. Direct observation of the second and third valence band in Wz InP nanowires using PL spectroscopy at high excitation power have been reported and, from these measurements, a crystal field splitting of 74 meV and a spin-orbit interaction energy of 145 meV were extracted. Based on the study of temperature-dependent optical properties, we have performed an investigation of the thermal escape processes of carriers and the electron-phonon coupling strength.

Temperature dependence of optical properties of InAs/InP quantum rod-nanowires grown on Si substrate

“…In that case, E 2 can be associated to the thermally populated high-energy states in the B-band. This thermal population is confirmed by the relative increase of B transition PL intensity along with the temperature as observed for WZ InP NWs [47]. Fig.…”

“…The best fitting parameters for the two models are summarized in Table 3 along with parameters from the literature. These parameters are closed to the values reported in the literature for ZB InAs which indicates that ZB and WZ InAs have similar thermal parameters as observed for InP [47,54] and GaAs [55] (even if there is some discrepancy for this semiconductor materiel [56]). The low temperature data points (<100 K) are systematically below the Varshni curves by about 5 meV.…”

Cu3-xP Nanocrystals as a Material Platform for Near-Infrared Plasmonics and Cation Exchange Reactions

“…The final InP NCs (red curve) did not show any feature in the NIR region and exhibited instead an absorption edge having its maximum at ∼800 nm from which we extrapolated a bandgap of 1.55 eV. This value is slightly larger than the bulk band gap of WZ InP (832 nm, 1.49 eV), 39 − 43 thus we believe that a quantum confinement of carriers might take place in our InP NCs. Since the Bohr radius of bulk zinc-blende InP is around 110 Å (11 nm), 44 the confinement in our InP nanoplatelets should be along their (001) direction (the one perpendicular to the basal facets).…”

Monolithic integration of InP on Si by molten alloy driven selective area epitaxial growth

“…The highest PL intensity and the narrowest full width at half maximum (FWHM) are observed from the InP/Si structures annealed at 600°C, and the signals from the samples annealed at lower and higher temperatures both have decreased PL intensities. The signal from the sample annealed at 600 °C shows a narrow PL peak at the energy corresponding to InP in zincblende crystal phase and a contribution from type-II band alignment [43][44][45] (see section S5 of the SI for details). The observed PL peaks show FWHM below 25 meV at 77 K and 55 meV at 300 K, which is attributed to the high crystallinity of the grown InP structures.…”