Strain dependence of In incorporation in m-oriented GaInN/GaN multi quantum well structures

Abstract

We demonstrate a strong dependence of the indium incorporation efficiency on the strain state in m-oriented GaInN/GaN multi quantum well (MQW) structures. Insertion of a partially relaxed AlInN buffer layer opens up the opportunity to manipulate the strain situation in the MQW grown on top. By lattice-matching this AlInN layer to the c- or a-axis of the underlying GaN, relaxation towards larger a- or smaller c-lattice constants can be induced, respectively. This results in a modified template for the subsequent MQW growth. From X-ray diffraction and photoluminescence measurements, we derive significant effects on the In incorporation efficiency and In concentrations in the quantum well (QW) up to x = 38% without additional accumulation of strain energy in the QW region. This makes strain manipulation a very promising method for growth of high In-containing MQW structures for efficient, long wavelength light-emitting devices.

Reduced nonradiative recombination in semipolar green-emitting III-N quantum wells with strain-reducing AlInN buffer layers

“…Earlier work focused on QWs grown on nonpolar m-plane substrates, where the AlInN layers were successfully used for strain management in a multiquantum well (MQW) structure. 15,16 In the present work, we address the influence of the growth substrate and a strain-reducing AlInN buffer layer on nonradiative recombination in GaInN/GaN QW structures grown on semipolar ð11 22Þ GaN templates to check whether a similar defect formation mechanism as found by Langer et al 10 on the c-plane can be observed. On ð11 22Þ GaN, AlInN can be grown lattice-matched to the ½11 2 3 (or c 0 -direction) at a 25.8% InN mole fraction and is compressively strained (%À 1:04%) in the other in-plane direction, ½1 100 or m-direction.…”

Green Electroluminescence from Radial m-Plane InGaN Quantum Wells Grown on GaN Wire Sidewalls by Metal–Organic Vapor Phase Epitaxy

“…The crystal orientation is known to have a significant impact on the MQW growth (growth rate and In composition), nevertheless no clear tendency about the In incorporation is reported in the literature on m -plane surfaces regarding the c -plane orientation due to the strong dependence on growth conditions . In the case of MOVPE, Horenburg et al recently reported that In incorporation is strongly dependent on the strain state of the m -plane InGaN/GaN MQW systems by adding an InAlN buffer layer either lattice-matched along the c -axis or a -axis . The higher In incorporation corresponds to the situation having the c -axis lattice matched and an elastic strain along the a -axis.…”

Microscopic analysis of interface composition dynamics in m-plane AlInN

“…A detailed analysis of the strain state, structural and optical properties of this structure, especially of the AlInN and the MQW, has been published elsewhere. 24) The sample has undergone an extensive high-resolution Xray diffraction (HRXRD) analysis 24) using a Panalytical X'Pert Pro system. In order to determine the composition, in-and out-of-plane lattice constants and to assess the strain state, on-and off-axis reciprocal space maps as well as relative scans of several reflections have been measured.…”

“…Further, AlInN has been demonstrated to act as a strain manipulating buffer layer in nonpolar multi quantum well structures, significantly increasing the indium incorporation into GaInN quantum wells. 24) Beyond that, efficient radiative recombination has been shown in m-plane AlInN over a wide spectral range. Therefore, its growth behaviour in nonbasal orientations is of particular interest.…”