Raman Spectroscopic Characterizations of Self-Catalyzed InP/InAs/InP One-Dimensional Nanostructures on InP(111)B Substrate using a Simple Substrate-Tilting Method

Abstract

We report optical phonon vibration modes in ensembles of self-catalyzed InP/InAs/InP multi core-shell one-dimensional nanostructures (nanopillars and nanocones) grown on InP(111)B substrates using liquid indium droplets as a catalyst via metal-organic chemical vapor deposition. We characterized the Raman vibration modes of InAs E1(TO), InAs A1(TO), InAs E1(LO), InP E1(TO), InP A1(LO), and InP E1(LO) from the ensemble of as-grown nanostructures. We also identified second-order Raman vibration modes, associated with InP E1(2TO), E1(LO+TO), and E1(2LO), in the InP/InAs/InP core-shell nanopillars and nanocones. Raman spectra of InP/InAs/InP nanopillars showed redshift and broadening of LO modes at low-frequency branches of InAs and InP. Due to the polar nature in groups III–V nanowires, we observed strong frequency splitting between InAs E1(TO) and InAs A1(LO) in InP/InAs/InP nanocones. The Raman resonance intensities of InP and InAs LO modes are found to be changed linearly with an excitation power. By tilting the substrate relative to the incoming laser beam, we observed strong suppression of low-frequency branch of InP and InAs LO phonon vibrations from InP/InAs/InP nanocones. The integrated intensity ratio of InP E1(TO)/E1(LO) for both nanostructures is almost constant at 0-degree tilt, but the ratio of the nanocones is dramatically increased at 30-degree tilt. Our results suggest that Raman spectroscopy characterization with a simple substrate tilting method can provide new insights into non-destructive characterization of the shape, structure, and composition of the as-grown nanostructures for the wafer-scale growth and integration processing of groups III–V semiconducting hetero-nanostructures into nanoelectronics and photonics applications.

Formation of a periodic structure on the surface of InP crystal during irradiation with bismuth ions

“…Such Raman spectra as in Fig. 7a-c are usually observed for nanowire-type structures of InP [17,18]. Another principal result of the analysis is the absence of peaks corresponding to the amorphous phase of InP for all considered irradiation doses.…”

Interface engineering on a Li metal anode for an electro-chemo-mechanically stable anodic interface in all-solid-state batteries

“…25 With a further increase in InI 3 to a molar ratio of 3 : 1 : 1, peaks of InP and β-In 2 S 3 clearly appeared in addition to those of PS 4 3− and P 2 S 7 4− (with a shoulder peak of P 2 S 6 4− ), suggesting that excessive InI 3 resulted in the precipitation of such side products. 26,27 Although these peaks were also observed in the solution with a molar ratio of 3 : 1 : 0.5, the intensity was almost negligible. Interestingly, the PS 4 3− peak at 420 cm −1 was not significantly shifted toward a low frequency but was close to the pure PS 4 3− peak position (Fig.…”

Layer-resolved release of epitaxial layers in III-V heterostructure via a buffer-free mechanical separation technique

“…Figure 3C shows the Raman spectra for process II. The two primary peaks of the Raman spectrum measured on the surface of the released layer correspond to the InP-like longitudinal optical (LO) mode and transverse optical (TO) mode ( 48 ). The main peaks observed on the surface of the remaining substrate correspond to the InAs-like LO mode and the GaAs-like LO mode ( 49 , 50 ).…”