Advanced characterization techniques including synchrotron radiation have been used to investigate the structural and electronic properties of doped silicon nanowires (NWs). Si L-edge, O K-edge and F K-edge XAS (x-ray absorption spectroscopy) spectra of silicon NWs at different doping levels have been collected at the BEAR beamline of the ELETTRA synchrotron radiation facility. XAS results show that the NWs structures are modified changing the type and level of doping and by the etching process. Optical Raman spectroscopy of NWs shows shifted and broadened first order optical mode, corresponding to a decrease in size of the crystallite domains inside the nanowires. The observed Raman shifts are compatible with the occurrence of a larger crystallite size in p-type NWs and smaller one in n-type NWs, in line with XAS results. Fabricated low-doped p-type NWs were also pressurized up to 24 GPa in a diamond anvil cell at room temperature and Raman scattering was recorded at selected pressures. The Si diamond crystal structure (dc-Si) is observed to persist up to ∼ 22 GPa, much higher than the phase transition onset (∼ 11 GPa) occurring in bulk silicon in the same experiment. © 2021, Springer Nature Switzerland AG.
Structural Properties of Porous Silicon Nanowires: A Combined Characterization by Advanced Spectroscopic Techniques
Rezvani S. J.
;Mijiti Y.;Gunnella R.;Pinto N.;Di Cicco A.
2021-01-01
Abstract
Advanced characterization techniques including synchrotron radiation have been used to investigate the structural and electronic properties of doped silicon nanowires (NWs). Si L-edge, O K-edge and F K-edge XAS (x-ray absorption spectroscopy) spectra of silicon NWs at different doping levels have been collected at the BEAR beamline of the ELETTRA synchrotron radiation facility. XAS results show that the NWs structures are modified changing the type and level of doping and by the etching process. Optical Raman spectroscopy of NWs shows shifted and broadened first order optical mode, corresponding to a decrease in size of the crystallite domains inside the nanowires. The observed Raman shifts are compatible with the occurrence of a larger crystallite size in p-type NWs and smaller one in n-type NWs, in line with XAS results. Fabricated low-doped p-type NWs were also pressurized up to 24 GPa in a diamond anvil cell at room temperature and Raman scattering was recorded at selected pressures. The Si diamond crystal structure (dc-Si) is observed to persist up to ∼ 22 GPa, much higher than the phase transition onset (∼ 11 GPa) occurring in bulk silicon in the same experiment. © 2021, Springer Nature Switzerland AG.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
