We have studied the introduction of deep levels in InGaAs/InP multi-quantum wells (MQW) grown by metalorganic vapor phase epitaxy using tert-butylarsine ((BuAsH2)-Bu-t) as arsenic precursor as well as chromium (bis-cyclopentadienyl chromium) and zinc (diethyl-zinc) as dopant elements able to promote recombination centres in the ternary alloy. We have utilized secondary-ion mass spectrometry to measure dopant concentrations and high-resolution X-ray diffraction for structural characterization. Particularly for the chromium-doped systems. frequency- and time-resolved optical spectroscopy of the MWQ ground-state transition confirms an increase of the carrier recombination rate upon an increase of defect density, while the electronic and structural properties of the sample are largely preserved. (C) 2002 Elsevier Science B.V. All rights reserved.