High quality InN/GaN heterostructures grown by migration enhanced metalorganic chemical vapor deposition

We report on the structural properties and optical and electrical characteristics of InN epitaxial layers grown on highly resistive GaN templates using migration enhanced metalorganic chemical vapor deposition (MEMOCVD). The material quality of InN improved significantly for the layer thickness larger than 150 nm. The highest extracted value of the room temperature electron mobility was close to 850 cm2/V s for samples with electron carrier concentration of ∼4×1018 cm−3. The measured dependence of the electron mobility on electron concentration is interpreted using the model accounting for ionized impurity scattering, polar optical scattering, and compensation. The MEMOCVD-grown material exhibited stronger photoluminescence (PL) compared to InN deposited using conventional metalorganic chemical vapor deposition. Room temperature PL spectra were similar to InN grown using molecular beam epitaxy (MBE) with peak emission at 0.8 eV. The obtained results demonstrate the potential of the MEMOCVD technique for deposition of high quality InN epitaxial layers at reduced temperatures comparable to those used in MBE growth.