Effect of matrix on InAs self-organized quantum dots on InP substrate

InAs self-organized quantum dots in In0.53Ga0.47As and In0.52Al0.48As matrices have been grown on InP substrates by molecular beam epitaxy. The dot size in InGaAs has been found to be 3-4 times larger, but the areal density about an order of magnitude smaller than that in InAlAs. Low-temperature photoluminescence (PL) of the InAs/InGaAs quantum dots is characterized by a narrow (35 meV) PL line as compared to that of InAs/InAlAs quantum dots (170 meV). Quantum dot formation increases the carrier localization energy as compared to quantum well structures with the same InAs thickness in a similar manner for both InAs/InGaAs and InAs/InAlAs structures, The effect of the barrier band gap on the optical transition energy is qualitatively the same for quantum well and quantum dot structures. The results demonstrate a possibility of controlling the quantum dot emission wavelength by varying the matrix composition. (C) 1998 American Institute of Physics.