Two-source coevaporation technique for synthesis of indium phosphide films with controlled composition

Synthesis of indium phosphide films with controlled composition by coevaporation technique has been demonstrated. Films with three different In:P ratios were deposited to represent phosphorous rich, stoichiometric and phosphorous poor InP films. Microstructural and compositional studies indicated films to be polycrystalline in nature, with grain size and shape varied with In:P ratio in the films. X-ray diffraction pattern indicated reflections from (1 1 1), (2 2 0) and (3 1 1) planes of InP only. The surface roughness of the films estimated from AFM studies was found to be 30 nm. PL spectrum measured at 10 K was dominated by a strong peak located ∼1.35 eV. Characteristic Raman peaks for InP at ∼306 cm−1 (TO) and ∼341 cm−1 (LO) were observed.

► Two source co-evaporation with assured reproducibility.
► Large grained polycrystalline films.
► Predominant zinc blende structure.
► Residual stress was lower in stoichiometric films.