Optical spectroscopy of GaN grown by metalorganic vapor phase epitaxy using indium surfactant

Abstract

The effect of In surfactant during metalorganic vapor phase epitaxial growth on sapphire substrates on the properties of GaN layers is studied using time-resolved photoluminescence, cathodoluminescence, and scanning electron microscopy. The samples are divided into two groups, where hydrogen and nitrogen, respectively, have been used as a carrier gas during growth. It is shown that In-doped samples have a lower dislocation density, a narrower photoluminescence linewidth, and a longer free exciton lifetime. The influence of indium is stronger for GaN layers grown in nitrogen-rich conditions. The improvements of structural and optical properties are attributed to the effect of In on dislocations.

MOVPE growth of InN buffer layers on sapphire

“…It was reported in the literature that indium deposition on the substrate prior to MOCVD growth promotes the InN nucleation [21]. On another hand, surfactant effect of indium on GaN surfaces has already been reported in the literature [22]. Moreover, for InN grown by MBE, it was reported in the literature that In-rich condition promotes surface diffusion and lateral growth [13].…”

Growth and characterization of thick GaN layers grown by halide vapour phase epitaxy on lattice-matched AlInN templates

“…The contrast in a panchromatic image is related to the intensity of radiative emission in different regions, and the dark spots correspond to areas with higher densities of non-radiative recombination centers. The dark spot density (DSD) is related to TDD [15] and gives a lower limit of the TDD in GaN. The measured DSD for the samples are summarized in Table 1.…”

Indium-facilitated growth and characterization of N-polar GaN by RF plasma-assisted molecular beam epitaxy

“…It was reported that the surface morphology of GaN [4][5][6] could be improved and film growth kinetics would be modified when indium was introduced during growth. The benefits due to the indium incorporation include improvement of optical and electrical properties such as decrease of the yellow luminescence (YL), better photoluminescence (PL) intensity with narrower full-width at half-maximum (FWHM) and higher carrier mobility [6][7][8][9]. Strain relief and reduction in dislocation density are credited for the enhanced film quality.…”