Low-temperature MBE growth and characteristics of InP-based AlInAs/GaInAs MQW structures

Basic development steps towards low-temperature molecular beam epitaxy of I nP-based AlInAs/GaInAs multiple quantum wells are presented. The achievemen t of unstrained material and the adjustment of 1.55 mum emission necessitat e modified growth conditions as compared to conventional growth. Single cry stalline growth down to a temperature as low as 100 degreesC was successful ly achieved as indicated by the appearance of superlattice peaks in the X-r ay diffraction spectra as well as 300 K photoluminescence emission. The tem poral development of transmission changes after optical excitation (pump-pr obe techniques) in the low-temperature material is predominantly governed b y two recombination paths. Modelling of this bi-exponential decay on the ba sis of a three-level approach delivers the characteristics of the main trap incorporated in the quantum well material when grown at low temperature. T he physical nature of this trap is attributed to As-Ga as supported by resu lts of beryllium doping. (C) 2001 Elsevier Science B.V. All rights reserved .