Characterization of InGaN/GaN multiple quantum well structures. Application to LEDs

InGaN/GaN Multi Quantum Well (MQW) structures were grown by MOCVD. For this study, var ious thicknesses of InGaN/GaN periods were investigated (from 9 0 to 130 Angstrom) as-well as the number of lattice periods (from 1 to 10). Transmission Electron Microscopy (TEM) revealed that the well/barrier inte rfaces are sharp. The (0002) High Resolution X-ray Diffraction (HRXRD) spec tra show multiple satellite peaks due to interferences on well/barrier inte rfaces. We observed a very accurate correlation between the thickness deduc ed from X-ray spectra and TEM. All these observations prove that the InGaN/ GaN interfaces are of high quality and well defined. The photoluminescence (300 K PL) peak intensity was shown to increase when: the number of wells i ncreases. Light Emitting Device (LED) structures have been grown following the above-mentioned model of MQW structures. Electroluminescence (EL) was p erformed on:the devices and the results are in accordance with the material structures involved.