High-quality, Cr-doped InGaAs/InP(001) MQWs grown by tert-butylarsine in a MOVPE apparatus

We have studied the introduction of deep levels in InGaAs/InP multi-quantum wells (MQW) grown by metalorganic vapor phase epitaxy using tert-butylarsine (tBuAsH2) 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.