AlGaAs/GaAs light emitting diode (LED) structures with an InMnAs ferromagnetic layer were grown by metal organic vapour phase epitaxy. Four different LED structures were studied. Their electroluminescence spectra revealed one peak at an energy of 1.467 eV in accordance with the design of the active quantum-well (QW) region. The incorporation of a 100 nm thick InMnAs layer into one of the LED structures led to a 50% decrease in the total optical output power of the LEDs compared with that of LEDs based on the QW structure that did not have InMnAs (reference structure). LEDs based on the structures with InMnAs exhibited dark currents between 1 mu A and 1 mA at V-R = -5 V. Those based on the reference LED structure had a dark current of 20 nA. Temperature dependent magnetic measurements proved that the LED structures with InMnAs were ferromagnetic at room temperature. (C) 2010 Elsevier B.V. All rights reserved.