Articles you may be interested inLow energy electron beam induced damage on InGaN/GaN quantum well structure J. Appl. Phys. 109, 083105 (2011); 10.1063/1.3574655 Indium redistribution in an InGaN quantum well induced by electron-beam irradiation in a transmission electron microscope Appl. Electron-beam-induced strain within InGaN quantum wells: False indium "cluster" detection in the transmission electron microscope Appl. Phys. Lett. 83, 5419 (2003); 10.1063/1.1636534 Investigation of V-Defects and embedded inclusions in InGaN/GaN multiple quantum wells grown by metalorganic chemical vapor deposition on (0001) sapphire Appl.

We report a study of the emission properties of InGaN/GaN quantum wells, grown by metalorganic vapour phase epitaxy, as a function of barrier-growth temperature, using continuous wave and time-resolved photoluminescence spectroscopy. We observe that high barrier-growth temperatures lead to a blue-shift of the photoluminescence, a reduction of the recombination lifetime, and a broadening of the emission linewidth. These effects are consistent with increased indium desorption during the pause preceding the growth of the barrier at higher temperatures. The blue-shift and the reduced lifetime are consistent with a reduction of the average indium concentration, while the increase of the linewidth is caused by the increase of the indium composition fluctuations due to the randomness of the desorption process. At the same time, the high barrier temperature samples have the highest photoluminescence efficiency at room temperature due to the reduced number of defects in the barrier.

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We report optical characterisation of AlGaN epitaxial layers and GaN/AlGaN quantum wells, grown by metalorganic vapour phase epitaxy on sapphire substrates. A combination of emission (photoluminescence) and absorption (photoluminescence excitation) spectroscopy provides information on the nature of the electronic states and on built-in electric fields resulting from piezoelectric and spontaneous polarisation effects. These fields are found to be considerably smaller than in previously reported work on similar structures.Introduction The wide band gap alloy AlGaN has numerous potential electronic and optoelectronic applications, such as HFETs, and UV photodetectors and emitters. However, despite this, AlGaN has been considerably less well studied than the InGaN system, due in part to difficulties in performing spectroscopy in the spectral region below 350 nm. Here we describe the application of photoluminescence (PL) and photoluminescence excitation (PLE) to study AlGaN epitaxial layers and GaN/AlGaN quantum wells (QWs). This combination of emission and absorption spectroscopy allows the material quality to be assessed, provides information on the electronic states and allows the effects of the built-in piezoelectric and spontaneous polarisation induced electric fields to be studied.