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InN and In-rich InGaN layers have been grown on GaN templates using the pulsed metalorganic chemical vapor deposition (MOCVD) technique and compared with analogous layers grown by conventional MOCVD. Structural investigations were performed using x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Surface morphology was studied using atomic force microscopy. Electrical and optical properties were studied using Hall measurements and photoluminescence (PL) spectroscopy. All layers were free of metal droplets. InN grown using pulsed MOCVD showed fairly low background electron concentration ( n = 8 × 10 cm to 9 × 10 cm) and high electron mobility ( μ = 644 cm V s). Structural studies revealed increase of size (from 100 nm to 500 nm) and decrease of density of InN islands at higher growth temperatures. For In-rich InGaN layers (In content 68% and 80%) the density of islands was similar to that in InN, while the diameter varied from 50 nm to 150 nm. Inhomogeneities of In and Ga distribution in the layers resulting in broadened XRD lines and PL bands are discussed. [ABSTRACT FROM AUTHOR]

In this paper, a superior-quality InN/p-GaN interface grown using pulsed metalorganic vapor-phase epitaxy (MOVPE) is demonstrated. The InN/p-GaN heterojunction interface based on high-quality InN (electron concentration 5.19 × 10 18 cm -3 and mobility 980 cm²/(V s)) showed good rectifying behavior. The heterojunction depletion region width was estimated to be 22.8 nm and showed the ability for charge carrier extraction without external electrical field (unbiased). Under reverse bias, the external quantum efficiency (EQE) in the blue spectral region (300⁻550 nm) can be enhanced significantly and exceeds unity. Avalanche and carrier multiplication phenomena were used to interpret the exclusive photoelectric features of the InN/p-GaN heterojunction behavior.