Controlling the morphology and wavelength of self-assembled coaxial GaAs/Ga(As)Sb/GaAs single quantum-well nanowires

Abstract

Four GaAs/Ga(As)Sb/GaAs SQW NWs with different morphologies and photon energies from 1.323 eV to 0.762 eV were achieved.

The Self-Catalyzed Growth of GaAsSb Nanowires on a Si (111) Substrate Using Molecular-Beam Epitaxy

“…This newly observed peak could be attributed to the Si-2TA peak and arose due to the sparsity of the GaAsSb NWs (refer to Figure 1e). mode peak associated with GaSb exhibited a blue-shift when compared to the GaSb NWs [16], which could be attributed to the substitution of Sb with As. Furthermore, in comparison to the GaAsSb nanowires with an FFSb of 6.43% and an FFSb of 21.95%, a novel Raman mode peak emerged in the vicinity of 303 cm −1 [38].…”

“…To gain further insights into the microscopic lattice structure associated with the integration of Sb in GaAsSb NWs, we conducted Raman spectroscopy, as depicted in Figure 5. Our previous study [16] included a Raman analysis of GaSb and GaAs NWs, revealing two distinct peaks at approximately 225.5 and 234.2 cm −1 for the GaSb's transverse optical (TO) and longitudinal optical (LO) modes, and 267.61 and 291.86 cm −1 for the GaAs's TO and LO modes, respectively. Figure 5a displays the Raman spectra of the GaAs NWs, which exhibited two mode peaks at around 267.4 and 291.3 cm −1 , corresponding to the GaAs TO and GaAs LO modes, respectively.…”

“…By growing III-V ternary alloys as NWs on Si, a broad range of compositions with significant strain and adjustable properties can be achieved, which is challenging to accomplish in the planar geometry. The narrow-bandgap ternary alloy offers a remarkable bandgap tunability spanning a wide range, from approximately 870 nm (GaAs) to 1720 nm (GaSb) [15,16]. This range features a high absorption coefficient and excellent carrier mobility characteristics, and it covers the wavelengths relevant to optical communications [17,18].…”

“…To date, the self-catalyzed vapor-liquid-solid (VLS) technique has remained the primary approach for growing the majority of ternary nanowires (NWs). This technique has proven instrumental in enabling the growth of intricate NW structures, including quantum well or core-multishell NWs [16][17][18][19][20]. These advancements pave the way for the expanded utilization of such NWs in electronic and optoelectronic devices.…”

Excitation-wavelength-dependent photoluminescence in GaAs nanowires under high-pressure

“…Gallium Arsenide (GaAs) NWs have received considerable research interest because of their direct bandgap, remarkable elasticity and stiffness [17], high electron mobility [18], near-infrared light-emitting [19], and high photosensitivity [12]. To further optimize the optical performance of GaAs NWs and facilitate their application in devices, several methods were actively pursued, such as epitaxial growth of a core-shell structure [20], doping of foreign elements [21,22], chemical passivation [23] and quantum-well/dots design [24,25]. In spite of these remarkable progresses, researchers are still seeking methods for dynamically modulating the performance of GaAs NWs.…”