Long wavelength emission in InxGa1-xAs quantum dot structures grown in a GaAs barrier by metalorganic chemical vapor deposition

We demonstrate a method to obtain room temperature long wavelength emission from InGaAs quantum dots (QDs) growth directly into a binary GaAs matrix. The wavelength is tuned from 1.26 up to 1.33 mum by varying the V/III ratio during growth of the GaAs cap layer, without using a seeding layer or InGaAs wells. Strong improvement in terms of line-shape narrowing and efficiency is obtained. In addition to the shift in wavelength we observe an impressive reduction of temperature dependent quenching of the emission efficiency, which decreases only by a factor of 3 between cryogenic temperatures and room temperature, very good for QD structures emitting at 1.3 mum. Photoluminescence spectroscopy and theoretical modeling were combined for interpretation of the results. (C) 2004 American Institute of Physics.