Synthesis and characterization of indium phosphide films prepared by co-evaporation technique

Polycrystalline indium phosphide films were successfully deposited on glass and Si substrates by co-evaporating indium and phosphorus from appropriate crucibles. Microstructural studies indicated the average crystallite size to be ∼78 nm. X-ray diffraction pattern indicated reflections from (111), (220) and (311) planes only. The surface roughness of the films was estimated to be 30 nm and the band gap as determined from the transmittance versus wavelength traces was found to be ∼1.42 eV. The PL spectrum measured at 300 K was dominated by a strong peak located ∼1.41 eV. The intensity of this peak increased significantly when recorded at lower (10 K) temperatures and shifted towards higher energy (∼1.54 eV). XPS studies indicated two peaks ∼444.5 eV and ∼451.9 eV, corresponding to peaks of 3d5/2 and 3d3/2 of In 3d core while the P 2p peak at ∼128.8 eV was assigned to only P in InP. Characteristics Raman peaks for InP at ∼303 cm−1 (TO) and ∼342 cm−1 (LO) were observed.

► High quality polycrystalline InP films synthesized by co-evaporation technique.
► EDAX studies indicated the In:P ratios ∼48:52 for all the films having low residual strain.
► Band gap of the films was ∼1.42 eV.
► PL studies indicated bound excitonic peak ∼1.41 eV.
► Raman peaks at ∼303 cm−1 (TO) and ∼342 cm−1 (LO) were observed.