Investigation of structural, phonon modes and electronic environment of GaP:Si nanostructure thin films

Abstract

In the present work, silicon-doped gallium phosphide (GaP:Si) nanostructure thin films were deposited using atmospheric pressure chemical vapor deposition (APCVD) with Si doping wt.% varied from 0.5 to 2.5 wt%. AFM revealed the roughness varied from 5.612 to 7.337 nm and the wire-like shape was changed to agglomerated shape with the increase in Si doping from 0.5 to 2.5 wt% in GaP:Si thin films. Fractal dimension varied from 1.931 to 2.519 with an increase in Si doping wt.%. The d-spacing, lattice constant (a), crystallinity fraction and crystallite size (D) increased with an increase in Si wt.% in the GaP:Si films. The dislocation density and microstrain of GaP:Si varied from 0.020 to 0.001 ( × 1014 1/m2) and −0.0052 to 0.0072 respectively due to thermal stress and defect distribution. The TO and LO phonon lifetime varied from 0.41 to 0.33 ps and 0.45 to 0.27 ps respectively for GaP:Si thin films.