Indium phosphide films prepared by flash evaporation technique: Synthesis and characterization

Indium phosphide films were deposited by flash evaporating InP powder (99.995%) on glass substrates. Microstructural information was obtained from transmission electron microscope and atomic force microscope (AFM) studies. The average value (~ 0.33 nm) of surface roughness of the films was determined by AFM. X-ray diffraction traces indicated reflections from (111), (220) and (311) planes only. The band gap was found to vary between ~ 1.94 eV and 1.96 eV. ε∞ varied between 11.58 and 11.89 while the plasma frequency (ωp,) were seen to vary between 8.52 and 8.59 × 1014 s− 1. The bonding environment in the films was determined from Raman and Fourier transformed infrared measurements. The experimental absorption spectra could be faithfully described by considering the effect of scattering by the ultra small crystallites in the film alone. Photoluminescence peak located at ~ 1.5 eV may be ascribed due to transitions from states arising out of phosphorous vacancy to the valance band. The shoulders of the peak ~ 1.5 eV may originate from the DA transitions between VP and InP.