Raman characterization of single-crystalline Ga_0.96Mn_0.04As:Zn nanowires realized by ion-implantation

Abstract

Recent progress in the realization of magnetic GaAs nanowires (NWs) doped with Mn has attracted a lot of attention due to their potential application in spintronics. In this work, we present a detailed Raman investigation of the structural properties of Zn doped GaAs (GaAs:Zn) and Mn-implanted GaAs:Zn (Ga 0.96 Mn 0.04 As:Zn) NWs. A significant broadening and redshift of the optical TO and LO phonon modes are observed for these NWs compared to as-grown undoped wires, which is attributed to strain induced by the Zn/Mn doping and to the presence of implantation-related defects. Moreover, the LO phonon modes are strongly damped, which is interpreted in terms of a strong LO phonon-plasmon coupling, induced by the free hole concentration. Moreover, we report on two new interesting Raman phonon modes (191 and 252 cm −1 ) observed in Mn ion-implanted NWs, which we attribute to E g (TO) and A 1g (LO) vibrational modes in a sheet layer of crystalline arsenic present on the surface of the NWs. This conclusion is supported by fitting the observed Raman shifts for the SO phonon modes to a theoretical dispersion function for a GaAs NW capped with a dielectric shell.

Evaluation of carrier density and mobility in Mn ion-implanted GaAs:Zn nanowires by Raman spectroscopy

“…Interestingly, the hole concentration reduced to a value of (2.5±0.5) ×10 19 cm −3 after annealing the NWs. Recently, we showed that annealing of GaAs:Zn NWs results in the formation of a crystalline As/oxide shell around the NWs [35]. The line shape analysis indicates that holes are trapped or compensated by defects present in the c-As/ oxide shell or by interface imperfections.…”

Electrical transport properties of InAs nanowires synthesized by a solvothermal method

“…In current research, quasi-one-dimensional (1D) semiconductor nanostructures have attracted tremendous attention because of their significance in understanding low-dimensional phenomena and potential applications in advanced biological, electronic and photonic nanoscale devices [1][2][3][4][5][6][7][8].…”

In-situ study of electrical transport in Pd/n-Si under high energy ion irradiation

“…Depending on the strength of S e and S n , the SHI irradiation can be utilized to modify the Schottky barrier and transport properties in a controlled fashion either by generating the defects near the MS interface or removing the present defects by dynamic annealing [10,14]. Besides creating the defects in a controlled way, the energetic heavy ions are also used for doping and modifying the transport properties in bulk as well as nanostructures [15][16][17][18][19]. So, understanding the influence of SHI irradiation on the performance of Schottky barrier devices is an important field of research with technological applications to design better radiation-hard electronic devices.…”