Optical and structural properties of InGaN/GaN short-period superlattices for the active region of light- emitting diodes

InGaN/GaN‐based green‐light‐emitting diodes with an inserted InGaN/GaN‐graded superlattice layer

“…As the emission wavelength of the InGaN QWs shift from blue to green spectral regimes, however, the internal quantum efficiency (IQE) decreases significantly, resulting in a problem that is often referred to as the “green gap;” reportedly, this problem is due to the high‐density defects that result from a large lattice misfit (11%) between the InN and GaN, and high QW polarization fields that lead to a reduction of the ratio involving the radiative recombination rate and the non‐radiative recombination rate . There have been numerous studies to overcome the green gap problem including the use of the following: non‐polar or semipolar GaN templates , InGaN‐based quantum dots (QDs) for active regions , and short‐period superlattices . These methods, however, require an additional fabrication step to slice the as‐grown templates along the desired plane, a complicated growth procedure to form QDs, and/or an exact analysis of the composition‐ratio variation with the growth temperature to achieve lattice‐matching conditions.…”

Single quantum well deep-green LEDs with buried InGaN/GaN short-period superlattice

“…6). So, these structures are not classical short-period SLs, but layered nanocomposites, which is confirmed by optical investigations as well [12]. It looks feasible that the material with such kind of structure can suppress the influence of GaN buffer domain boundaries on InGaN QW formation, promoting for it a uniform composition.…”

“…1) [10][11][12] by alternating growth of In 0.1 Ga 0.9 N and growth interruption (GI) where the alkyl precursors were switched off and the carrier gas composition was changed from pure N 2 to a mixture of N 2 :H 2 ¼7:3. In this procedure, the indium concentration on the surface is governed by an interplay between InGaN decomposition during the GI, indium segregation, desorption, and incorporation into InGaN during subsequent growth.…”

Formation of Three-Dimensional Islands in the Active Region of InGaN Based Light Emitting Diodes Using a Growth Interruption Approach

“…The first set contains InGaN QWs that were overgrown by a GaN layer immediately after their formation (Table I, set 1). The reference structure contains 3 nm-thick InGaN layers grown at 760 C with a TEGa flow of 250 sccm and ammonia flow of 7 slm (Table I, 21,22 The series is divided into two sets. The first set contains 3.8 nm-thick In x Ga 1−x N QWs with x ≤ 18% that were overgrown by a GaN layer immediately after their formation (Table II, All structures were studied by various characterization methods, including X-ray diffractometry, transmission electron microscopy (TEM) and spectroscopy of photoluminescence (PL) and electroluminescence (EL).…”